Article: 223528 of rec.radio.amateur.antenna From: "John Passaneau" Subject: Re: Thomas & Betts UV Resistant Tie Wraps: Any Experiences With For Out Of Door Usage ? Date: Thu, 13 Apr 2006 09:38:32 -0400 Message-ID: References: "Robert11" wrote in message news:BPednWi15vkNzaPZRVn-pg@comcast.com... > Hi, > > Was wondering if anyone has any experience using the "Premium" Thomas & > Betts, Black, "UV-Resistant" > nylon tie wraps out of doors ? > > e.g., do they become brittle after a fer years due to very cold temps, or > UV ? > > Or, do they really hold up well, etc. ? > > Thanks, > Bob > > Hi Bob: I have no experience with that brand, but I've used UV resistant (black tie warps) for years. The feedlines on my tower are held up with them and I've noticed no degradation in them for the last 4 years. For what its worth, in the past I've used Scotch #33 black electrical tape and it has held hard-line and coax to my tower for 5 to 6 years with no problem. Some professionals I know use electrical tape for all but the largest runs of hard-line. -- John Passaneau Penn State University Physics Dept. jxp16@psu.edu Article: 223529 of rec.radio.amateur.antenna From: "Yuri Blanarovich" References: <1144647060.456337.126840@e56g2000cwe.googlegroups.com> <3989-443A71AB-132@storefull-3256.bay.webtv.net> <123orli9a52nr5e@corp.supernews.com> <123qihrf94k80e8@corp.supernews.com> <4Ng%f.138$732.128@fe10.lga> <123ra2kngip1a54@corp.supernews.com> Subject: Re: Current across the antenna loading coil - from scratch Message-ID: Date: Thu, 13 Apr 2006 09:42:35 -0400 "Richard Clark" wrote in message news:i5tr32hoo6ebelfh6uh9jh9ea8eao0bbvf@4ax.com... > On Wed, 12 Apr 2006 23:07:20 -0400, "Yuri Blanarovich" > wrote: > >>I am really done here > Hope triumphs over experience. yep, "hope" with pictures, measurements and descriptions (no good) vs. "experience" = it can't be, but, but, but... ("proof") how does the coil have higher current at the top if it loses radiation through capacitance to W8JI? "Experienced" silencio!!! There is your sign! Richard, keep up sticking needles, that really sheds light on the subject Happy Easter to everyone, even unbelievers! Yuri da BUm Article: 223530 of rec.radio.amateur.antenna From: "Caveat Lector" Subject: Mag Mount on aluminum ? Message-ID: Date: Thu, 13 Apr 2006 07:09:53 -0700 Since aluminum is non magnetic, I would assume a mag-mount vertical would not couple properly to a aluminum ground plane. Thoughts ? -- CL -- I doubt, therefore I might be ! Article: 223531 of rec.radio.amateur.antenna From: "stargatesg1" References: <443c671f$0$10677$afc38c87@news.optusnet.com.au> Subject: Re: HF discone ????????????? Message-ID: <6tt%f.10580$8g3.4793@trnddc02> Date: Thu, 13 Apr 2006 14:44:18 GMT I actually had the chance to use one of these at a Titan II missile site in Wichita, KS. when I was in the USAF back in the 80's. I had been dispatched out to the base to do some maintenance on the VHF/UHF radio equipment they used, and our departure was delayed for awhile due to a snow storm. I asked the site commander if I could use the HF gear to make a few amateur radio contacts and he gave me permission. WOW what good signal reports! I was running the full legal limit on 75 and 40 meters through it and whatever I could hear I could work. I made about a dozen contacts and the commander must have gotten a little worried and ordered me to stop. I guess I was lucky he let me make any contacts at all considering the situation. Nice memory:-) Anyway, the antenna was HUGE to say the least! it was made of cable for the skirt and large tubing for the hat radials. I would guess about 100-150'+ across the bottom of the skirt. I haven't thought about that in years. Thanks for reminding me of those times:-) Loved being in the Air Force! RoD KD0XX "Spock" wrote in message news:443c671f$0$10677$afc38c87@news.optusnet.com.au... > Hello Everyone > I saw somewhere that the us navy used on some of it's ships hf discone > antennas. Were they any good? are they practical? what are the pros and > cons? are they used commercially? > > Than you. > > > > > --- > avast! Antivirus: Outbound message clean. > Virus Database (VPS): 0615-1, 11/04/2006 > Tested on: 12/04/2006 12:04:06 PM > avast! - copyright (c) 1988-2005 ALWIL Software. > http://www.avast.com > > > Article: 223532 of rec.radio.amateur.antenna From: "Caveat Lector" References: Subject: Re: Mag Mount on aluminum ? Message-ID: Date: Thu, 13 Apr 2006 07:57:19 -0700 Ha - indeed Richard -- no for home use. Would the aluminum act as a proper ground plane ? Like a steel sheet would. -- CL -- I doubt, therefore I might be ! "Richard Clark" wrote in message news:uvos329cssntcbd1r3baehmcsd1la2d20p@4ax.com... > On Thu, 13 Apr 2006 07:09:53 -0700, "Caveat Lector" > wrote: > >>Thoughts ? > > The antenna will probably fall over at 20-30 MPH if that's what you > mean. > > 73's > Richard Clark, KB7QHC Article: 223533 of rec.radio.amateur.antenna From: fmmck@aol.com (Fred McKenzie) Subject: Re: Improving FM in building Date: Thu, 13 Apr 2006 11:05:52 -0400 Message-ID: References: <2bf27$443d1c89$45011502$10556@KNOLOGY.NET> <443D5362.A5E09CCD@shaw.ca> In article , Ian Jackson wrote: > Irv, > Have you any idea about the lengths which cable TV operators go to to > keep their networks RF-tight (ingress and egress)? Feed an outlet into > antenna? Maybe not such a good idea!! Ian- In that case, why not get the Cable TV people to install it for you? They can use an isolation amplifier that will prevent outside signals from being fed back into their system. Fred Article: 223534 of rec.radio.amateur.antenna From: "Caveat Lector" References: <22ss32pfu81c2e8bgdnre49jaiubkc906f@4ax.com> Subject: Re: Mag Mount on aluminum ? Message-ID: Date: Thu, 13 Apr 2006 08:49:06 -0700 Thanks folks Someone posed the question to me and I thought I'd better check with the experts. -- CL -- I doubt, therefore I might be ! "Richard Clark" wrote in message news:22ss32pfu81c2e8bgdnre49jaiubkc906f@4ax.com... > On Thu, 13 Apr 2006 07:57:19 -0700, "Caveat Lector" > wrote: > >>Ha - indeed Richard -- no for home use. >>Would the aluminum act as a proper ground plane ? >>Like a steel sheet would. > > Hi OM, > > Sure, to the same degree of your having enough metal to resonate it. > Sometimes even that doesn't matter. > > 73's > Richard Clark, KB7QHC Article: 223535 of rec.radio.amateur.antenna From: richardharrison@webtv.net (Richard Harrison) Subject: Re: Current across the antenna loading coil - from scratch Date: Thu, 13 Apr 2006 11:32:20 -0500 Message-ID: <6093-443E7D14-1029@storefull-3254.bay.webtv.net> References: <1144920639.132371.257750@z34g2000cwc.googlegroups.com> Tom, W8JI wrote: "It isn`t standing waves, it is missing electrical degrees." That could be sarcasm because it certainly could be standing waves. In a coil the RF signal travels as a surface wave around the turns of the coil (helix) at about the velocity of light. Hopper`s rule says this is about one foot in a billionth of a second (one nanosecond). Self inductance can`t magically induce the signal in one end of a coil instantaneously into the opposite end of the coil. Here`s why. Current in the coil induces voltage and current lags the applied voltage by 90-degrees (1/4 of the time required for a complete cyclr). That`s a delay. Antenna systems produce a reflection from the open-circuit at the tip of an antenna. The incident wave reaching the tip reverses its direction becoming the reflected wave, traveling in the opposite direction from the incident wave. You likely have seen the interference pattern produced by incident and reflected waves on a transmission line in a book. The same pattern starts at the tip of an antenna not terminated in its Zo. At certain points on the signal path the voltages in the two waves will be in phase and will add, while at other points they will be out of phase and subtract. The points along the path where the two voltages are in phase are points of maximum voltage and minimum current and are spaced one-half wavelength apart. The points along the path where the two voltages are 180-degrees out of phase are points of minimum voltage and maximum current and are also spaced one-half wavelength apart. The distance between alternate points is one-quarter wavelength. Coil, wire, free-space, whever you have an incident wave and its reflection on a path, you will get this interference pattern on a conductor. So, a loading coil is going to have variations of voltage and current caused by an energy reflection with or without coupling to the rest of the universe. Best regards, Richard Harrison, KB5WZI Article: 223536 of rec.radio.amateur.antenna Subject: Re: Thomas & Betts UV Resistant Tie Wraps: Any Experiences With For Out Of Door Usage ? From: Ed References: Message-ID: Date: 13 Apr 2006 17:13:59 GMT "Robert11" wrote in news:BPednWi15vkNzaPZRVn-pg@comcast.com: > Hi, > > Was wondering if anyone has any experience using the "Premium" Thomas > & Betts, Black, "UV-Resistant" > nylon tie wraps out of doors ? > > e.g., do they become brittle after a fer years due to very cold temps, > or UV ? > > Or, do they really hold up well, etc. ? My experience with the black UV resistant ties from many manufacturers is that they do last years in direct sunlight. ... don't even compare with white ties that will degredate within a single year. Also, a Blue colored tie has been available for some time that is supposedly guarantied to last up to 15 years outdoors. Having used them in years past, it does appear to be true... although they are quite expensive. I forget the manufacturer. In years past many techs have just used short lengths of insulated 12guage solid wire to hold feedlines to a tower. This is still a valid way to go.... cheaper than ties, and they last very long, too. Ed K7AAT Article: 223537 of rec.radio.amateur.antenna From: John Ferrell Subject: Re: Source code of program COAX_VLF Message-ID: References: Date: Thu, 13 Apr 2006 20:04:22 GMT Thank yoy, de W8CCW On Thu, 13 Apr 2006 20:18:39 +0100, "Reg Edwards" wrote: >I have made available from my website the source code of program >COAX_VLF. It may be of interest to transmission line addicts. > >Regarding the mathematics involved with the calculations you will not >find any references in your Bibles on which you appear to depend so >much. > >But you may, at least, judge from the comments alongside the code what >is involved. That much may be rather obvious. > >Roy and others have been criticising me for years about not disclosing >what's behind my programs in the hope of inducing me to disclose the >trade secrets. There are no secrets. Just common sense. > >Well Roy, now you have it all. What do you make of it? Can you make >any sense out of it? Don't expect me to spend the next few years >trying to educate you. I havn't the time to spare. In any case I >should expect to be paid at the rate of 100 US$ per hour. > >My programs are free to USA citizens. Make what use of them as you >will. And don't quibble about them on the grounds that they are >founded merely on the opinions of a foreigner. > >"Patriotism is not enough" - Nurse Edith Cavell. >---- >Reg. > John Ferrell W8CCW Article: 223538 of rec.radio.amateur.antenna From: Jim - NN7K Subject: Re: Thomas & Betts UV Resistant Tie Wraps: Any Experiences With References: Message-ID: Date: Thu, 13 Apr 2006 21:19:41 GMT Black tie wraps do definately hold up longer than regular tie wraps, but will still give up after several years. Used to use them for Telephone cables, as well as coax. Wish I remembered the brand name , but if you Permanent ties, there is a make of METAL- plastic coated ties, that 1) last forever, and 2), can be reused. Try Greybar Electric , and W.W. Grainger. Tiewraps are also available in different colors, (they were used to mark multi -pair telephone cables, in 25 pair bunches), which are great for clean installs of wireing, in vehicles (blend in with the vehicle colors), makeing them nearly invisible. As info, Jim NN7K Robert11 wrote: > Hi, > > Was wondering if anyone has any experience using the "Premium" Thomas & > Betts, Black, "UV-Resistant" > nylon tie wraps out of doors ? > > e.g., do they become brittle after a fer years due to very cold temps, or UV > ? > > Or, do they really hold up well, etc. ? > > Thanks, > Bob > > Article: 223539 of rec.radio.amateur.antenna From: "M.M." Subject: Re: Magnetic antenna base in pickup truck References: <1144945801.830133.244250@v46g2000cwv.googlegroups.com> Message-ID: <_NA%f.11449$iU2.11096@fed1read01> Date: Thu, 13 Apr 2006 16:04:27 -0700 WØCBF wrote: > Hello, > > I have a Ranger pickup with a spray in Line X bed liner. I am > interested using a magnetic base for a Hamstick HF antenna possibly one > of the brands that have 3 magnets in a triangle. ... I tried that with my Ranger. Didn't work too well. Never could get a decent swr on the Hamstick (10M). I finally bought one of those mounts that goes in the stake pocket and it worked great. I think the guy advertises in QST. They're about the same price as one of those mag mounts but get the antenna up out of the bed. If you can't find the ad, I'll sell you mine since I don't use it any more (gave the Ranger to my kid). 73... Mark AA7TA Article: 223540 of rec.radio.amateur.antenna From: "Dan/W4NTI" References: <443c671f$0$10677$afc38c87@news.optusnet.com.au> Subject: Re: HF discone ????????????? Message-ID: Date: Thu, 13 Apr 2006 23:09:36 GMT "Spock" wrote in message news:443c671f$0$10677$afc38c87@news.optusnet.com.au... > Hello Everyone > I saw somewhere that the us navy used on some of it's ships hf discone > antennas. Were they any good? are they practical? what are the pros and > cons? are they used commercially? > > Than you. > > > > --- > avast! Antivirus: Outbound message clean. > Virus Database (VPS): 0615-1, 11/04/2006 > Tested on: 12/04/2006 12:04:06 PM > avast! - copyright (c) 1988-2005 ALWIL Software. > http://www.avast.com > > > While in SAC (Strategic Air Command) I was assigned to Lockbourne AFB in Ohio. We had two of the super large HF Discones. Took up several acres of real estate as I remember...Not a good choice for Field Day. Basic unity gain 3 to 30. Worked great. However the two Rhombics beat them out hands down. And YES I did play on the ham bands with them. And that's another story. Dan/W4NTI Article: 223541 of rec.radio.amateur.antenna Date: Thu, 13 Apr 2006 18:17:13 -0500 From: Tom Ring Subject: Re: Current across the antenna loading coil - from scratch References: <123orli9a52nr5e@corp.supernews.com> <123qihrf94k80e8@corp.supernews.com> <4Ng%f.138$732.128@fe10.lga> <123ra2kngip1a54@corp.supernews.com> Message-ID: <443edbfa$0$1014$39cecf19@news.twtelecom.net> Richard Clark wrote: > On Thu, 13 Apr 2006 09:42:35 -0400, "Yuri Blanarovich" > wrote: > > >>Happy Easter to everyone, even unbelievers! > > > Hi Yuri, > > I was at Seder last night. Are you calling me an unbeliever? > > 73's > Richard Clark, KB7QHC Unfortunately Richard, to many, including some I am acquainted with, you would be considered much worse than that. Minnesota is not as broad minded as they like to pretend. Religious hangings weren't that long ago here. And, as the grandson of Polish Jews who, for some unknown reason, hid their ancestry to the point where I was raised Catholic, I am obviously conflicted! ;) tom K0TAR Article: 223542 of rec.radio.amateur.antenna Subject: Re: Thomas & Betts UV Resistant Tie Wraps: Any Experiences With For Out Of Door Usage ? From: Ed References: Message-ID: Date: 13 Apr 2006 23:53:10 GMT > Black tie wraps do definately hold up longer than regular tie wraps, > but will still give up after several years. Used to use them for > Telephone cables, as well as coax. Wish I remembered the brand name , I'll bet Panduit was the likely name for them! They are one of the larger makers of all kinds of ties, plastic, metal, etc. I used them for decades. Do a Google search for Panduit Tie wrap and see what turns up. Ed K7AAT Article: 223543 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: Source code of program COAX_VLF Date: Thu, 13 Apr 2006 17:41:25 -0700 Message-ID: <123trtlt9p7jea7@corp.supernews.com> References: Reg Edwards wrote: > . . . > Roy and others have been criticising me for years about not disclosing > what's behind my programs in the hope of inducing me to disclose the > trade secrets. There are no secrets. Just common sense. > . . . There you go again, Reg, making things up and presenting them as fact. I challenge you to cite a single example of my criticizing you for not disclosing your source code. I have, on the other hand, criticized you several times for lying. Consider this another one. Roy Lewallen, W7EL Article: 223544 of rec.radio.amateur.antenna Date: Thu, 13 Apr 2006 21:33:06 -0500 From: Tom Ring Subject: Re: Current across the antenna loading coil - from scratch References: <123orli9a52nr5e@corp.supernews.com> <123qihrf94k80e8@corp.supernews.com> <4Ng%f.138$732.128@fe10.lga> <123ra2kngip1a54@corp.supernews.com> <443edbfa$0$1014$39cecf19@news.twtelecom.net> <1144971342.258949.214160@e56g2000cwe.googlegroups.com> Message-ID: <443f09e2$0$1008$39cecf19@news.twtelecom.net> K7ITM wrote: > (Continuing the basenote drift, since the basenote thread is pretty > much a mess anyway...) > > So it's not clear to me who might be calling whom an unbeliever. Both > Christians and Jews celebrate seder. Maybe it would be those of some > other faith? It's interesting to me--and sad--that so many whose > religion teaches that God is all-powerful and too great to be known > fully by any person are intolerant of others whose religions teach just > the same thing. The intolerance seems as common between sects of > nominally the same religion as between religions. If you can't ever > fully know your god, who are you to say it's not the same god as the > one someone else worships differently, or as someone else worships as a > set of gods? > > Hey, we might as well be discussing religion as loading coils... > > Ducking, > Tom No, it's just that certain groups of Xians, not a majority but getting too populous for my taste, seem to think they are the be all end all, and everyone else is going to HELL, even other Xians, especially Catholics. And those that aren't Xian, fuggetaboutit, they are all damned even if they are Good Samaritans and kinder than Mother Theresa, because they don't belive in the RIGHT THINGS. tom K0TAR Article: 223545 of rec.radio.amateur.antenna From: "Sal M. Onella" References: Subject: Re: Mag Mount on aluminum ? Message-ID: <8xF%f.477$QP4.476@fed1read12> Date: Thu, 13 Apr 2006 21:27:47 -0700 "Caveat Lector" wrote in message news:PYs%f.12664$bm6.7806@fed1read04... > Since aluminum is non magnetic, I would assume a mag-mount vertical would > not couple properly to a aluminum ground plane. > > Thoughts ? > -- > CL -- I doubt, therefore I might be ! >\ Not to worry. All-aluminum antennas are quite practical, as it is the conductivity of the counterpoise/radials that makes it work. Also, please consider the many vertical antennas working off buried copper wires for their ground plane. If you need magnetic properties on a large aluminum surface (roof?), then cement a small sheet of steel to the aluminum with any handy adhesive. NOT stainless, though; it's generally non-magnetic. Article: 223546 of rec.radio.amateur.antenna From: "Jae" Subject: Hidaka VS33 antenna Date: Fri, 14 Apr 2006 22:35:10 +1000 Message-ID: <443f96ff$1_1@news.iprimus.com.au> Can SKS help me out with the spacings for traps on this antenna ?. Have an unassembled antenna that I am trying to rebuild. Regards VK3CVF John Melbourne... Article: 223547 of rec.radio.amateur.antenna From: "Wilder Scott" Subject: A warning! Message-ID: Date: Fri, 14 Apr 2006 10:02:18 -0400 I think Bush and his administration probably had better turn their attention to the U.S. and forget about Iraq & Iran, or we're DONE FOR! Check this out! Pat http://halturnershow.com/aztlan.caps.wmv Article: 223548 of rec.radio.amateur.antenna From: "jimmiefender@bellsouth.net" References: Subject: Re: Mag Mount on aluminum ? Message-ID: Date: Fri, 14 Apr 2006 14:27:59 -0400 "Caveat Lector" wrote in message news:PYs%f.12664$bm6.7806@fed1read04... > Since aluminum is non magnetic, I would assume a mag-mount vertical would > not couple properly to a aluminum ground plane. > > Thoughts ? > -- > CL -- I doubt, therefore I might be ! I tried this on a 2M antenna and it didnt work so well. My theory was that since the antenna was not firmly attached to the Al then the capacitve coupling between the base of the antenna and the Al groundplane was off. Fixed the problem by soldering radials to a coffee can lid and placing the antenna on this. Article: 223549 of rec.radio.amateur.antenna From: "Steve Nosko" Subject: Re: Mag Mount on aluminum ? Date: Fri, 14 Apr 2006 14:51:27 -0500 Message-ID: References: "jimmiefender@bellsouth.net" wrote in message news:uNR%f.786$MM6.80@bignews3.bellsouth.net... > > "Caveat Lector" wrote in message > news:PYs%f.12664$bm6.7806@fed1read04... > > Since aluminum is non magnetic, I would assume a mag-mount vertical would > > not couple properly to a aluminum ground plane. > > > > Thoughts ? > > -- > > CL -- I doubt, therefore I might be ! > > I tried this on a 2M antenna and it didnt work so well. My theory was that > since the antenna was not firmly attached to the Al then the capacitve > coupling between the base of the antenna and the Al groundplane was off. > Fixed the problem by soldering radials to a coffee can lid and placing the > antenna on this. > > Aluminum is a decent conductor and as a result, it will work. Possibly, the Lack of the magnetic attractive force was not pulling the magnet very close or firmly to the plate. This could be helped by putting something on the bottom of the aluminum / aluminium to get some force and closer spacing, such as another magnet. You can also generate a lot of posts / re-posts on the operating theory of mag mount antennas and what this capacitance does... 73, Steve, K9DCI I tried to maintain a global flavour... Article: 223550 of rec.radio.amateur.antenna From: "Steve Nosko" Subject: Re: A warning! Date: Fri, 14 Apr 2006 14:46:11 -0500 Message-ID: References: <35Q%f.38$yQ.26@trnddc07> Doesn't matter. Site unacceptable anyway. While there may be many on this group who understand the situation we are in with Georgie Porgie, this isn't the place to post nor give those doing so any reason to continue... Steve N. "John - KD5YI" wrote in message news:35Q%f.38$yQ.26@trnddc07... > Wilder Scott wrote: > > I think Bush and his administration probably > > had better turn their attention to the U.S. and > > forget about Iraq & Iran, or we're DONE FOR! Check this out! Pat > > > > http://halturnershow.com/aztlan.caps.wmv > > > > > > > > > Not Found > The requested document was not found on this server. > > Web Server at halturnershow.com Article: 223551 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: Mutual capacitance of an 8 conductor system Date: Fri, 14 Apr 2006 14:25:37 -0700 Message-ID: <12404qird4ts65f@corp.supernews.com> References: <1144930785.151800.313130@j33g2000cwa.googlegroups.com> Sriram wrote: > Hi, > > Is there a derivation for calculating mutual capacitance and mutual > inductance in an 8 conductor system? I did manage to find one for a 4 > conductor system but unable to extend that to 8 conductors. Any > suggestions on books or papers for reference would be of great help. > Thanks in advance. _Fundamentals of Coupled Lines and Multiwire Antennas_ by Hidenari Uchida, published by Sasaki Printing and Publishing Company, Ltd., 1967. Roy Lewallen, W7EL Article: 223552 of rec.radio.amateur.antenna Message-ID: <4440567C.20907@fuse.net> Date: Fri, 14 Apr 2006 22:12:12 -0400 From: jawod Subject: Re: A warning! References: <35Q%f.38$yQ.26@trnddc07> Steve Nosko wrote: > Doesn't matter. Site unacceptable anyway. While there may be many on this > group who understand the situation we are in with Georgie Porgie, this isn't > the place to post nor give those doing so any reason to continue... Steve N. > > "John - KD5YI" wrote in message > news:35Q%f.38$yQ.26@trnddc07... > >>Wilder Scott wrote: >> >>>I think Bush and his administration probably >>>had better turn their attention to the U.S. and >>>forget about Iraq & Iran, or we're DONE FOR! Check this out! Pat >>> >>>http://halturnershow.com/aztlan.caps.wmv >>> >>> >>> >> >> >>Not Found >>The requested document was not found on this server. >> >>Web Server at halturnershow.com > > > I agree this is not the place...but please don't count ME in with Cheney's lap dog. john Article: 223553 of rec.radio.amateur.antenna From: "David G. Nagel" Subject: Re: Interesting antenna. Semi-fractal?? Date: Fri, 14 Apr 2006 21:19:43 -0500 Message-ID: <1240m2apghs3bec@corp.supernews.com> References: <1145052775.297265.98520@v46g2000cwv.googlegroups.com> <1145057035.515651.107190@j33g2000cwa.googlegroups.com> Richard Clark wrote: > On 14 Apr 2006 16:23:55 -0700, "K7ITM" wrote: > > >>John Popelish wrote: >> >>>K7ITM wrote: >>> >>>>http://us.gizmodo.com/gadgets/gadgets/space-antenna-design-evolved-by-hive-of-borg-156502.php >>> >>>Do you have any idea what the performance specs are for this antenna? >> >>No idea at all. A friend knows I'm interested in antennas, and sent me >>the link simply as something interesting. Since things are WAY too >>quiet here today, I thought I'd post it. ;-) > > > Hi Tom, John, > > The form shown is a variation of what I called the triangle sweep some > 8 years ago. I fed it dipole style, they do similar sections in > parallel against a ground plane. > http://www.qsl.net/kb7qhc/antenna/fractal/Triangle%20Sweep%20Dissection/3dtri-42.htm > The following page shows one construction out 5 iterations in a > planar, not 3 space form: > http://www.qsl.net/kb7qhc/antenna/fractal/Triangle%20Sweep/index.htm > There are as many variations as could be expected, but calling them > "fractal" strains the definition - especially when the debate got down > to claims that every good conventional antenna design was an hidden > example of fractal principles. > > If you drill down through the links, they are challenging Walt's > Quadrafilar design of some 35 years ago. Curiously, one frequency > sweep of the "better" of two models had pretty crummy SWR. I couldn't > find the design goal. > > 73's > Richard Clark, KB7QHC Ut Oh! Your in trouble now.... :)... Article: 223554 of rec.radio.amateur.antenna From: "Sal M. Onella" References: Subject: Re: Mag Mount on aluminum ? Message-ID: <6WZ%f.557$QP4.244@fed1read12> Date: Fri, 14 Apr 2006 20:39:46 -0700 "jimmiefender@bellsouth.net" wrote in message news:uNR%f.786$MM6.80@bignews3.bellsouth.net... > > "Caveat Lector" wrote in message > news:PYs%f.12664$bm6.7806@fed1read04... > > Since aluminum is non magnetic, I would assume a mag-mount vertical would > > not couple properly to a aluminum ground plane. > > > > Thoughts ? > > -- > > CL -- I doubt, therefore I might be ! > > I tried this on a 2M antenna and it didnt work so well. My theory was that > since the antenna was not firmly attached to the Al then the capacitve > coupling between the base of the antenna and the Al groundplane was off. > Fixed the problem by soldering radials to a coffee can lid and placing the > antenna on this. > > I was able to make a magmount work OK with only a steel TV tray. I decided I wanted an emergency 2M antenna, so I got a ladder and attached the antenna whip from the high point inside my garage roof. The VSWR was awful until I took an old TV tray up and -- *bonk* -- stuck it to the dangling magmount base. Voila! Good VSWR. So, it doesn't take much. If the coffee can lid is what works, then that's what you do!! Article: 223555 of rec.radio.amateur.antenna From: "Sal M. Onella" References: <35Q%f.38$yQ.26@trnddc07> Subject: Re: A warning! Message-ID: Date: Fri, 14 Apr 2006 20:51:56 -0700 "John - KD5YI" wrote in message news:35Q%f.38$yQ.26@trnddc07... > Wilder Scott wrote: > > I think Bush and his administration probably > > had better turn their attention to the U.S. and > > forget about Iraq & Iran, or we're DONE FOR! Check this out! Pat > > > > http://halturnershow.com/aztlan.caps.wmv > > > > > > > > > Not Found > The requested document was not found on this server. > > Web Server at halturnershow.com FYI: It came up for me. It's clips of public speeches by people who oppose border controls. I think there was one guy with an HT on his belt, so the OP can claim it was ham radio-related, hi hi. Article: 223556 of rec.radio.amateur.antenna From: Butch Magee Subject: nag mount Date: Sat, 15 Apr 2006 00:01:49 -0500 Message-ID: <1240vi1hapapg07@corp.supernews.com> Mag mt. will wurk just fine if you use sufficient grey tape. The magic is that aluminum sticks really good to gray tape, but is a lousy sticker to mag mts. Magnetic antennas won't even stick, I tried. Butch Article: 223557 of rec.radio.amateur.antenna From: "jimmiefender@bellsouth.net" References: <443c671f$0$10677$afc38c87@news.optusnet.com.au> Subject: Re: HF discone ????????????? Message-ID: Date: Sat, 15 Apr 2006 03:59:04 -0400 "Spock" wrote in message news:443c671f$0$10677$afc38c87@news.optusnet.com.au... > Hello Everyone > I saw somewhere that the us navy used on some of it's ships hf discone > antennas. Were they any good? are they practical? what are the pros and > cons? are they used commercially? > > Than you. > > > > --- > avast! Antivirus: Outbound message clean. > Virus Database (VPS): 0615-1, 11/04/2006 > Tested on: 12/04/2006 12:04:06 PM > avast! - copyright (c) 1988-2005 ALWIL Software. > http://www.avast.com > > > Remember seeing one down in South Florida back in the early 80s. Part of quite an extensive antenna farm. Looked govt. Article: 223558 of rec.radio.amateur.antenna From: John - KD5YI Subject: Re: fun with loading References: Message-ID: Date: Sat, 15 Apr 2006 14:55:22 GMT Dave wrote: > How would you guys who are stuck in an endless thread of loading coils like > to take on 'linear loading'?? are the currents the same at each end of the > loading line?? do they cancel completely along the length of the loading > line? does the loading line replace so many degrees of the length of the > elements or cause some kind of delay??? > > the antenna i am working on is an m-squared 40m4lldd where, for example, the > reflector is 50' tip to tip, about 10' out from the boom there is an > insulator, a rod about 9' long connects with a metal bracket on each side of > the insulator and folds back toward the boom where they are connected with > an aluminum shorting bar that then uses a piece of phillystrand that goes to > an element truss support bracket. then of course beyond the insulator is > another 15' or so of element, the tips are adjusted to tune the elements. > What's "linear loading"? What's a "loading line"? Article: 223559 of rec.radio.amateur.antenna Date: Sat, 15 Apr 2006 10:51:36 -0500 From: Tom Ring Subject: 50 years ago - Not antenna related, but probably interesting to many Message-ID: <44411688$0$1015$39cecf19@news.twtelecom.net> I'm sure there are some here who will have memories stirred by this article. http://tvtechnology.com/features/news/2006.04.12-n_the_video_tape_02.shtml Tom K0TAR Article: 223560 of rec.radio.amateur.antenna From: "Yuri Blanarovich" References: Subject: Re: fun with loading Message-ID: Date: Sat, 15 Apr 2006 12:06:45 -0400 "Dave" wrote in message news:lq-dnTNXcoNal9zZRVn-rA@crocker.com... > > "John - KD5YI" wrote in message > news:uP70g.270$_s5.47@trnddc04... >> Dave wrote: >>> How would you guys who are stuck in an endless thread of loading coils >>> like to take on 'linear loading'?? are the currents the same at each >>> end of the loading line?? do they cancel completely along the length of >>> the loading line? does the loading line replace so many degrees of the >>> length of the elements or cause some kind of delay??? >>> As far as acting as loading element, it is another form of (real life) loading inductance, so it is similar to loading coil, but worse performer in the loaded Yagi situation. Have look at the end of my article http://www.k3bu.us/loadingcoils.htm where EZNEC plot shows current distribution along the loaded Yagi element, using loading stubs. >>> the antenna i am working on is an m-squared 40m4lldd where, for example, >>> the reflector is 50' tip to tip, about 10' out from the boom there is an >>> insulator, a rod about 9' long connects with a metal bracket on each >>> side of the insulator and folds back toward the boom where they are >>> connected with an aluminum shorting bar that then uses a piece of >>> phillystrand that goes to an element truss support bracket. then of >>> course beyond the insulator is another 15' or so of element, the tips >>> are adjusted to tune the elements. >>> >> >> >> What's "linear loading"? What's a "loading line"? > > i probably didn't do a very good job of describing it, but basically you > take a shorter than 1/4 wave element and cut it in the middle somewhere > and put in an insulator. instead of putting in a loading coil as you > would normally expect you use a shorted piece of parallel wire line to > tune it. in the case of the 40m4lldd the parallel wire line is made of > aluminum rod and is folded back to use it as a truss for the element. > > It has been found and published in articles in CQ magazine, where loading stubs were replaced by the loading coils and the performance of the antenna like KLM 80m 3 el. loaded Yagi was improved significantly. Better gain and better and cleaner F/B and pattern. Real modeling and measurements confirmed that, regardless what the "flat earth - same current" believers claim and try to "prove". Folding the loading stubs along the elements seems to distort the current distribution along the element and deteriorate its' performance. So you are better off replacing loading stubs with loading coils, and that's what the whole debate about the current distribution, reality and understanding it is about. 73 and GL Yuri, K3BU.us Article: 223561 of rec.radio.amateur.antenna From: "Hal Rosser" References: Subject: Re: Thomas & Betts UV Resistant Tie Wraps: Any Experiences With For Out Of Door Usage ? Message-ID: Date: Sat, 15 Apr 2006 17:33:28 -0400 "Robert11" wrote in message news:BPednWi15vkNzaPZRVn-pg@comcast.com... > Hi, > > Was wondering if anyone has any experience using the "Premium" Thomas & > Betts, Black, "UV-Resistant" > nylon tie wraps out of doors ? > > e.g., do they become brittle after a fer years due to very cold temps, or UV > ? > > Or, do they really hold up well, etc. ? > > Thanks, > Bob I worked at an electrical supply for several years, and When Georgia Power was building Plant Vogtle nuclear plant, they must have purchased a truckload or more TY-525-MX (black WP tie-raps). Paperwork had to be traceable back to the factory. We also sold a lot of of Panduit brand tie-raps. I think they are of equal quality. The black ones have carbon in the mix to retard UV damage. If you take one more step (like put a wrap of tape (3M#88) over the tie-rap) or even paint it - it should give more years of life. --but like one post mentioned - Panduit -and T&B if I recall both have stainless steel versions. Article: 223563 of rec.radio.amateur.antenna From: "Yuri Blanarovich" References: <4ie242db8e606932th5cq8pbn2prfvks16@4ax.com> Subject: Re: fun with loading Message-ID: Date: Sat, 15 Apr 2006 21:44:55 -0400 Hi Richard, I thank you for posting such revealing evaluation of my deficient, misleading knowledge. Yes, my web site is full of old no good stuff. Even my C6AYB picture is too many pounds old. Anyone with spec of antenna knowledge can see that "G5RV" is operated as dipole, judging by the standing wave current distribution, and it is not cardinal sin to call it G5RV dipole or vice versa. If I can get away from deflecting mumbo-jumbo and over holidays, I will start working on the project. Looks like audience here is looking for sticking needles rather than providing answers and suggestions to questions. The main thrust of question posted here was, should he stay with loading stubs or do something better. I described what was done, and stubs suck, coils are MUCH better and that current distribution is what it is and illustrated in that "butchered" drawing by W5DXP. I humbly bow in view of your much better, educational posting. I am sure the questioner is fully satisfied with your answers and solutions. Happy Easter from bankrupt designer 73 Yuri, K3BU "Richard Clark" wrote in message news:4ie242db8e606932th5cq8pbn2prfvks16@4ax.com... > On Sat, 15 Apr 2006 12:06:45 -0400, "Yuri Blanarovich" > wrote: > >>it is similar to loading coil, but worse performer in >>the loaded Yagi situation. Have look at the end of my article >>http://www.k3bu.us/loadingcoils.htm > > Hi Yuri, > > As usual, your statement has nothing to do with your link. What is > worse, this EZNEC model is from a third party who is not available to > comment as to the accuracy of your statements about performance. > > Even more is the compounding of error at the link: > "G5RV antenna using inductors in the form of loading stubs" > Clearly, then, it is NOT a G5RV. > > When we continue with the commentary we find: > "When simple inductance in Eznec is inserted in place of the > stubs, the current erroneously is shown as the same at the both > ends of the inductor." > Clearly, then, the model designer who expected something other does > not know how to design the model. It would seem after several years > of corrections to this error you continue to publish, that you would > have updated your page by now. > > It is easy to offer broken solutions. This group sees many of them > that are then used to discredit either the tool or the theory. What > these broken models reveals are the bankrupt designer. > > Perhaps you should vet the material from your contributors more > closely. > > 73's > Richard Clark, KB7QHC Article: 223564 of rec.radio.amateur.antenna From: "Yuri Blanarovich" References: <4ie242db8e606932th5cq8pbn2prfvks16@4ax.com> Subject: Re: fun with loading Message-ID: Date: Sun, 16 Apr 2006 01:33:10 -0400 "Richard Clark" wrote > > How much better? This sounds like a fractal sales pitch. > Your HOW MUCH is getting a bit TOO MUCH! Comparing this to fractal sales pitch??? That is TOO MUCH! Go read the article in CQ magazine if you like to find out details. Geeez! Guy asked question, I gave some answer, better than nothing that you gave or anyone else. If you expect me to write a book, than wait! Looks like you got TOO MUCH time and enjoy sticking needles. Sorry I don't write exactly as you would wish. Get a life! 73 Yuri Article: 223565 of rec.radio.amateur.antenna From: internetDotComs.com Subject: for sale: internetDotComs.com Date: Sun, 16 Apr 2006 19:47:29 +0200 Message-ID: domain for sale: internetdotcoms.com http://www.afternic.com/name.php?id=11866440 Article: 223566 of rec.radio.amateur.antenna From: "Yuri Blanarovich" References: <1145180243.458726.20590@i39g2000cwa.googlegroups.com> Subject: Re: fun with loading Message-ID: Date: Sun, 16 Apr 2006 20:58:06 -0400 Chrystos Voskres! Christ has risen! May he nelighten those confused and enlighten them! Nice going Tom, W8JI! 73 Yuri, K3BU.us Article: 223567 of rec.radio.amateur.antenna From: Buck Subject: Re: paint antenna? Message-ID: References: <122u6ah1aa5iv2e@corp.supernews.com> Date: Sun, 16 Apr 2006 21:24:50 -0400 On Wed, 05 Apr 2006 14:05:47 GMT, Silfax wrote: >I would try putting up a vertical stripe on the building and then paint the >radials on the sidewalk/street. This could be the ultimate in stealth. Make the >radials look like a crosswalk or the center line down the street. You could >even paint the curb, to make a no parking zone radial. > > Why paint radials? Just paint the entire surface for 260 FEET in diameter. Then you can use a vertical for any band from 160 up with infinite radials in the circle. -- 73 for now Buck N4PGW Article: 223568 of rec.radio.amateur.antenna From: Buck Subject: Re: paint antenna? Aluminum paint? Message-ID: <9lr542dqlira9c1qeq79mtrbprn1hi4djm@4ax.com> References: Date: Sun, 16 Apr 2006 21:27:05 -0400 I have seen my father use aluminum paint from way back in the 60's. I haven't seen it lately, not that I have looked, but I wonder how it would work..... Buck N4PGW -- 73 for now Buck N4PGW Article: 223569 of rec.radio.amateur.antenna From: Buck Subject: Re: Must 300 ohm feedline be kept completely clear of contact w anything? Message-ID: References: <1239aaafdv8fa49@corp.supernews.com> Date: Sun, 16 Apr 2006 21:55:45 -0400 >In general there is a magnetic/electric field between the conductors in >twinlead feed line. >Dave WD9BDZ Dave, Just to clarify, is the 'magnetic/electric field' to which you refer the same as saying 'electromagnetic field'? I am just trying to clarify whether it is just how you expressed it or if you are making a distinctive difference. Thanks Buck -- 73 for now Buck N4PGW Article: 223570 of rec.radio.amateur.antenna From: Buck Subject: Re: Mag Mount on aluminum ? Message-ID: References: Date: Sun, 16 Apr 2006 22:25:31 -0400 On Thu, 13 Apr 2006 07:09:53 -0700, "Caveat Lector" wrote: >Since aluminum is non magnetic, I would assume a mag-mount vertical would >not couple properly to a aluminum ground plane. > >Thoughts ? Put a steel plate below the aluminum so the magnet won't fall over. Electrically, it should work on aluminum as the ground will still conduct when the magnet touches the aluminum. If nothing else, the capacitive connection through the base of the antenna should be about the same as it is on the steel. my thoughts N4PGW buck -- 73 for now Buck N4PGW Article: 223571 of rec.radio.amateur.antenna From: Buck Subject: Re: Mag Mount on aluminum ? Message-ID: References: <6WZ%f.557$QP4.244@fed1read12> Date: Sun, 16 Apr 2006 22:27:36 -0400 On Fri, 14 Apr 2006 20:39:46 -0700, "Sal M. Onella" wrote: > >"jimmiefender@bellsouth.net" wrote in message >news:uNR%f.786$MM6.80@bignews3.bellsouth.net... >> >> "Caveat Lector" wrote in message >> news:PYs%f.12664$bm6.7806@fed1read04... >> > Since aluminum is non magnetic, I would assume a mag-mount vertical >would >> > not couple properly to a aluminum ground plane. >> > >> > Thoughts ? >> > -- >> > CL -- I doubt, therefore I might be ! >> >> I tried this on a 2M antenna and it didnt work so well. My theory was that >> since the antenna was not firmly attached to the Al then the capacitve >> coupling between the base of the antenna and the Al groundplane was off. >> Fixed the problem by soldering radials to a coffee can lid and placing the >> antenna on this. >> >> > >I was able to make a magmount work OK with only a steel TV tray. > >I decided I wanted an emergency 2M antenna, so I got a ladder and attached >the antenna whip from the high point inside my garage roof. The VSWR was >awful until I took an old TV tray up and -- *bonk* -- stuck it to the >dangling magmount base. Voila! Good VSWR. So, it doesn't take much. If >the coffee can lid is what works, then that's what you do!! > Try a pizza pan -- 73 for now Buck N4PGW Article: 223572 of rec.radio.amateur.antenna From: "David G. Nagel" Subject: Re: Must 300 ohm feedline be kept completely clear of contact w anything? Date: Sun, 16 Apr 2006 21:38:18 -0500 Message-ID: <1245vtaahrsbh31@corp.supernews.com> References: <1239aaafdv8fa49@corp.supernews.com> Buck wrote: >>In general there is a magnetic/electric field between the conductors in >>twinlead feed line. >>Dave WD9BDZ > > > Dave, > > Just to clarify, is the 'magnetic/electric field' to which you refer > the same as saying 'electromagnetic field'? I am just trying to > clarify whether it is just how you expressed it or if you are making a > distinctive difference. > > Thanks > Buck > Buck You are correct in your interpretation of my stumbling words. The main thing is close proximity to another conductive material will affect the transmission of energy on twin lead. I hope that I have helped you. Amateur radio is a fascinating field of endeavor. Your education does not ever stop. Dave Article: 223573 of rec.radio.amateur.antenna From: Buck Subject: Re: Must 300 ohm feedline be kept completely clear of contact w anything? Message-ID: References: <1239aaafdv8fa49@corp.supernews.com> <1245vtaahrsbh31@corp.supernews.com> Date: Sun, 16 Apr 2006 22:42:09 -0400 On Sun, 16 Apr 2006 21:38:18 -0500, "David G. Nagel" wrote: >Buck wrote: >>>In general there is a magnetic/electric field between the conductors in >>>twinlead feed line. >>>Dave WD9BDZ >> >> >> Dave, >> >> Just to clarify, is the 'magnetic/electric field' to which you refer >> the same as saying 'electromagnetic field'? I am just trying to >> clarify whether it is just how you expressed it or if you are making a >> distinctive difference. >> >> Thanks >> Buck >> >Buck > >You are correct in your interpretation of my stumbling words. >The main thing is close proximity to another conductive material will >affect the transmission of energy on twin lead. >I hope that I have helped you. Amateur radio is a fascinating field of >endeavor. Your education does not ever stop. > >Dave Thanks, and yes, the education continues. -- 73 for now Buck N4PGW Article: 223574 of rec.radio.amateur.antenna From: Owen Duffy Subject: Re: fun with loading Message-ID: References: <1145180243.458726.20590@i39g2000cwa.googlegroups.com> <1145227446.811948.31350@g10g2000cwb.googlegroups.com> Date: Mon, 17 Apr 2006 03:50:34 GMT On 16 Apr 2006 15:44:06 -0700, "K7ITM" wrote: >OK, I gotta take issue with the part that says, > >"> A transmission line, even a very good one, generally has a Q of >> someplace around 20-75. The definition of Q I am using is reactance >> over ESR. Say you need a reactance of 400 ohms to resonate an antenna. >> Linear or stub loading would add a series resistance of 5 to 20 ohms as >> loss resistance at that point in the system. >" > >I know that transmission line Q varies all over the place: it's much >more reasonable to use it in a resonator at high frequencies than low, >and line construction makes a big difference too. To back this up with >numbers, I just ran some calcs (actually put together a little Scilab >program to run them for me) on four different lines: (a) is RG-8/RG-213 >type line with solid poly dielectric, (b) is 75 ohm air insulated coax >in an 0.5" ID copper tube, (c) is balanced two-wire line made with >12AWG (~2mm) wire spaced 2" (~5cm) on centers), and (d) is two 0.625" >OD copper tubes spaced 3" on center. > >For a 1/8 wave section of line shorted at the far end, the calculated >impedances and Qs are: > >line a, 10MHz: 0.622+j50, Q=80 >line a, 100MHz: 0.197+j50, Q=254 >line a, 1000MHz: 0.0622+j50, Q=800 I tried these numbers in the line loss calculator at http://www.vk1od.net/tl/tllce.php using Belden 8267 of 2.475m length for 0.125 wavelengths and Zload=0.0000000001. The input Z I got was a little higher at 0.88+j50 (probably slightly different approximation of Zo used in the calcs), yeilding a Q of 57. The Q is quite dependent on line length, decreasing as length increases towards a quarter wave. I suspect this is not a good method of analysing behaviour when the line elements are field coupled to other radiator elements, the currents in each leg are not necessarily equal and opposite. Owen -- Article: 223575 of rec.radio.amateur.antenna From: Dave Heil Subject: Re: Thomas & Betts UV Resistant Tie Wraps: Any Experiences With References: Message-ID: Date: Mon, 17 Apr 2006 03:57:27 GMT Hal Rosser wrote: > I worked at an electrical supply for several years, and When Georgia Power > was building Plant Vogtle nuclear plant, they must have purchased a > truckload or more TY-525-MX (black WP tie-raps). Paperwork had to be > traceable back to the factory. We also sold a lot of of Panduit brand > tie-raps. I think they are of equal quality. I used to sell the things in large quantities while working for a Cincinnati electronics distributor. The T&B's are pricey, but for a reason. They have a stainless steel barb to lock the ty-wrap (their trademarked name for the devices). It is much stronger than most competitors molded nylon barb. The black, uv treated ty-wraps work very, very well. I'll admit that as a radio amateur, I use the generic uv resistant ones and they also do the job. I generally tape over them. Dave Heil K8MN Article: 223576 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: paint antenna? Aluminum paint? Date: Sun, 16 Apr 2006 21:48:26 -0700 Message-ID: <12467gtb8mvjg38@corp.supernews.com> References: <9lr542dqlira9c1qeq79mtrbprn1hi4djm@4ax.com> Buck wrote: > I have seen my father use aluminum paint from way back in the 60's. I > haven't seen it lately, not that I have looked, but I wonder how it > would work..... As a guess, very badly. The aluminum in the paint is in the form of small particles, each probably covered with an oxide coating. So the conductivity would be very poor, even if the paint dried in such a way as to bring the individual particles into contact with each other (which it very well might not). Roy Lewallen, W7EL Article: 223577 of rec.radio.amateur.antenna From: Owen Duffy Subject: Re: fun with loading Message-ID: <38r6429t5021v46j4cb4a9047uf30bctr6@4ax.com> References: <1145180243.458726.20590@i39g2000cwa.googlegroups.com> <1145227446.811948.31350@g10g2000cwb.googlegroups.com> <1145254113.447279.155260@z34g2000cwc.googlegroups.com> Date: Mon, 17 Apr 2006 10:43:57 GMT On Mon, 17 Apr 2006 08:41:36 +0100, "Reg Edwards" wrote: >You dim witts are calculating Q incorrectly. > Reg, that is just so polite! >Q = X / R > >where R is the RF resistance of the conductor and X is the reactance >of the conductor's inductance. You first have to calculate >inductance. > So, you state that the ratio X/R is an acceptable way to express the Q of an inductor, why is it unacceptable to express the Q of a two terminal device with an equivalent series impedance of 0.88+j50 (where 0.88 is the RF series resistance of the network and 50 is the series inductive reactance of the element) as 50/0.88 or 57? Aren't the effiency implications (for that was the context) for a 50 ohm reactance created with a TL stub as described just the same as for a coil with 50 ohms of inductive reactance and 0.88 ohms of series (RF) resistance, ie a coil with the same Q factor? Owen -- Article: 223578 of rec.radio.amateur.antenna From: Buck Subject: Re: paint antenna? Aluminum paint? Message-ID: <8ev642pfr5fkvtc7tlvqr2b4164keg3s2q@4ax.com> References: <9lr542dqlira9c1qeq79mtrbprn1hi4djm@4ax.com> <12467gtb8mvjg38@corp.supernews.com> Date: Mon, 17 Apr 2006 07:37:26 -0400 On Sun, 16 Apr 2006 21:48:26 -0700, Roy Lewallen wrote: >Buck wrote: >> I have seen my father use aluminum paint from way back in the 60's. I >> haven't seen it lately, not that I have looked, but I wonder how it >> would work..... > >As a guess, very badly. The aluminum in the paint is in the form of >small particles, each probably covered with an oxide coating. So the >conductivity would be very poor, even if the paint dried in such a way >as to bring the individual particles into contact with each other (which >it very well might not). > >Roy Lewallen, W7EL I figured there must be some problem with it's conductivity if someone just invented paint to be conductive, but I hadn't tried it. Thanks -- 73 for now Buck N4PGW Article: 223579 of rec.radio.amateur.antenna From: "Hi" Subject: Vertically Polorized Omni Slot Antenna Date: Mon, 17 Apr 2006 13:56:19 -0500 Message-ID: <1247p6p3cdursca@corp.supernews.com> This is a horizontally powerized omni slot antenna. http://tinyurl.com/kbwkf Does anyone know if its possible to make a vertically polerized omni slot antenna? Matt Article: 223580 of rec.radio.amateur.antenna From: "Hi" Subject: Re: Vertically Polorized Omni Slot Antenna Date: Mon, 17 Apr 2006 14:34:44 -0500 Message-ID: <1247reqls3891e0@corp.supernews.com> References: <1247p6p3cdursca@corp.supernews.com> <1145302170.914834.97730@v46g2000cwv.googlegroups.com> > If I recall correctly, nope. > > A vertically polarized slot antenna will have an azimuth pattern like a > dipole. I was thinking if the slots were cut horizontally rather then vertically. Won't work? Matt > If you want a vertically polarized omnidirectional antenna, you build a > collinear array of vertical elements. If you want a horizontally > polarized omnidirectional antenna, you build a collinear array of > everything EXCEPT those elements, and feed that. A slot radiates the > same way that an antenna element of the same size and shape would > radiate, but the E and H fields are interchanged, and therefore has the > opposite polarization. > > Look up Babinet. > > 73, > Dan > N3OX > www.n3ox.net > Article: 223581 of rec.radio.amateur.antenna From: "Ken Bessler" Subject: Source for antenna? Message-ID: Date: Mon, 17 Apr 2006 15:17:21 -0500 I need a compact antenna for receiving from 0.030-1.800 mhz - I figure an active antenna will work - does anyone have links to either a build it yourself article or a commercial antenna? Receiver overload is NOT a big issue (TS-850SAT)..... -- 73's de Ken KG0WX - Kadiddlehopper #11808, Flying Pigs #-1055, Grid EM17io, TS-850SAT, Elecraft XG2, Tenna Dipper, Heath GD-1B Article: 223582 of rec.radio.amateur.antenna From: "Hal Rosser" References: Subject: Re: Thomas & Betts UV Resistant Tie Wraps: Any Experiences With For Out Of Door Usage ? Message-ID: Date: Mon, 17 Apr 2006 17:31:24 -0400 "Dave Heil" wrote in message news:HmE0g.3434$Fy2.1460@newsread3.news.pas.earthlink.net... > I used to sell the things in large quantities while working for a > Cincinnati electronics distributor. The T&B's are pricey, but for a > reason. They have a stainless steel barb to lock the ty-wrap (their > trademarked name for the devices). *************** That's right. but the regestered name is TyRap. TY525M was the best selling one we sold. ********** Article: 223583 of rec.radio.amateur.antenna From: "Hi" Subject: Re: Vertically Polorized Omni Slot Antenna Date: Mon, 17 Apr 2006 18:08:39 -0500 Message-ID: <12487vvg8511g57@corp.supernews.com> References: <1247p6p3cdursca@corp.supernews.com> <1145302170.914834.97730@v46g2000cwv.googlegroups.com> <1247reqls3891e0@corp.supernews.com> >>I was thinking if the slots were cut horizontally rather then vertically. >>Won't work? > > Hi Matt, > > No, it won't. Thanks for the response. Any sort of waveguide based antenna that will work as vertical omni? Matt Article: 223584 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Current across the antenna loading coil - from scratch References: <1144647060.456337.126840@e56g2000cwe.googlegroups.com> <3989-443A71AB-132@storefull-3256.bay.webtv.net> <123orli9a52nr5e@corp.supernews.com> <123rg6prdklphe0@corp.supernews.com> Message-ID: <9kW0g.11860$4L1.1293@newssvr11.news.prodigy.com> Date: Tue, 18 Apr 2006 00:23:33 GMT Roy Lewallen wrote: > The amount the magnitude of the current drops across an inductor is > determined primarily by the amount of inductance and the capacitance > from the inductor to ground or the other half of the antenna. This is > easily explained by simple lumped constant circuit theory. How does lumped constand circuit theory handle the phase shift through the inductance? It is certainly NOT zero as your measured. -- 73, Cecil http://www.qsl.net/w5dxp Article: 223585 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Current across the antenna loading coil - from scratch References: <1144647060.456337.126840@e56g2000cwe.googlegroups.com> <1144708348.601210.298690@e56g2000cwe.googlegroups.com> <4nB_f.67497$Jd.30975@newssvr25.news.prodigy.net> <5nC_f.5711$YT1.592@bgtnsc04-news.ops.worldnet.att.net> <6ZF_f.64716$H71.32645@newssvr13.news.prodigy.com> Message-ID: Date: Tue, 18 Apr 2006 00:25:10 GMT Gene Fuller wrote: > I gave you a very specific reference to demonstrate your supposition was > incorrect. You came back with nothing but, "Because I say so." You have > not offered one shred of backing for your constant Vf argument. Good Grief, Gene, can't I have a 6 day motorcycle in piece without you saying something that is not true? -- 73, Cecil http://www.qsl.net/w5dxp Article: 223586 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Current across the antenna loading coil - from scratch References: <1144647060.456337.126840@e56g2000cwe.googlegroups.com> <3989-443A71AB-132@storefull-3256.bay.webtv.net> <123orli9a52nr5e@corp.supernews.com> <123qihrf94k80e8@corp.supernews.com> <4Ng%f.138$732.128@fe10.lga> <123ra2kngip1a54@corp.supernews.com> Message-ID: Date: Tue, 18 Apr 2006 00:25:48 GMT Gene Fuller wrote: > Do you suppose that maybe the displacement current can actually work in > either direction? I guess magical thinking works in any directions. -- 73, Cecil http://www.qsl.net/w5dxp Article: 223587 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Current across the antenna loading coil - from scratch References: <1144647060.456337.126840@e56g2000cwe.googlegroups.com> <3989-443A71AB-132@storefull-3256.bay.webtv.net> <123orli9a52nr5e@corp.supernews.com> <123qihrf94k80e8@corp.supernews.com> <4Ng%f.138$732.128@fe10.lga> <123ra2kngip1a54@corp.supernews.com> <1144906021.162617.242800@i39g2000cwa.googlegroups.com> Message-ID: <0nW0g.11863$4L1.11529@newssvr11.news.prodigy.com> Date: Tue, 18 Apr 2006 00:26:36 GMT K7ITM wrote: > Yes, some time earlier today than that exchange, I posted elsewhere in > this thread a specific circuit, complete with values, how the same > thing is easily accomplished with the infamous ideal lumped components. > No standing waves need apply. But of course if one used distributed > reactances, one could easily get the same effect, and the analysis can > easily be done w/o any reference to standing or travelling waves. How about the phase shift? -- 73, Cecil http://www.qsl.net/w5dxp Article: 223588 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Current across the antenna loading coil - from scratch References: <1144647060.456337.126840@e56g2000cwe.googlegroups.com> <3989-443A71AB-132@storefull-3256.bay.webtv.net> <123orli9a52nr5e@corp.supernews.com> <123qihrf94k80e8@corp.supernews.com> <4Ng%f.138$732.128@fe10.lga> <123ra2kngip1a54@corp.supernews.com> <1144956612.522290.68020@j33g2000cwa.googlegroups.com> Message-ID: Date: Tue, 18 Apr 2006 00:30:45 GMT w8ji@akorn.net wrote: > What it is NOT possible to do is make a coil change current without > that third path to the outside world. Standing waves will not do it, > missing antenna degrees will not do it. That's a really strange thing to say, Tom. It happens all the time inside a piece of coax with reflections. There's no third path to the outside world, yet the standing waves inside a piece of coax certainly cause the current to change. -- 73, Cecil http://www.qsl.net/w5dxp Article: 223589 of rec.radio.amateur.antenna From: "Ed" Subject: 40 meter beam for sale Message-ID: Date: Tue, 18 Apr 2006 00:50:21 GMT M Squared brand, model 40M3L. Several years old but never unboxed, stored inside, dusty but new in every way. Present price is $1092.00, I will take $650 for it. Pick-up only in Dallas, Texas. KV5I eh54@sbcglobal.net Article: 223590 of rec.radio.amateur.antenna From: "Yuri Blanarovich" References: Subject: Re: fun with loading Message-ID: Date: Mon, 17 Apr 2006 23:03:56 -0400 "Richard Clark" wrote in message news:mkq342pdgumknhuh368nkupcseahm5etd5@4ax.com... > On Sat, 15 Apr 2006 12:06:45 -0400, "Yuri Blanarovich" > wrote: > >>As far as acting as loading element, it is another form of (real life) >>loading inductance, so it is similar to loading coil, but worse performer >>in >>the loaded Yagi situation. Have look at the end of my article >>http://www.k3bu.us/loadingcoils.htm > > Hi Yuri, > > Now, when we actually "look" at the design at your link, we find we > don't know much about: Here is the information from my web site as described by Barry, W9UCW: "Here are some actual measurements of current below and above loading coils. 92" mast, using a HI-Q coil (openwound airdux, 2 1/2"d) with small thermocouple type meters mounted on the insulated coil support. First for 40m, moving the coil in the mast from base to center to top (with hat) and reresonating. Base --100ma below & 66ma above Center --100ma below & 45ma above Top --100ma below & 37ma above Then, same test but for 30m Base --100ma below & 75ma above Center --100ma below & 60ma above Top --100ma below & 52ma above On a long, skinny 160 resonator with 25pf of top hat and whip, mounted on an 8' mast, I read 100ma below and 65ma above the coil. Because of the constant claim that this must be due to the fact that the coil is so big compared to a wavelength, I measured the in and out current on a TOROIDAL loading coil used on a 20m mobile antenna. It was a 78" base mast (including spring and mount) with a 38" top whip (including 12" of alum. tubing for adjustment). Below --100ma & Above --79ma When I moved the coil to the top of the mast and made a horizontal "X" top hat to resonate it back on the same freq, I got Below --100ma & Above --47ma So, It happens even in a totally shielded loading coil with miniscule power going thru it! Kirchoff has no laws about current being the same on both ends of inductors. His current law is about one POINT in a circuit and his voltage law is about a closed loop." ... and some significant difference W9UCW in field strength measured between the base and center loading coil: "The actual difference in signal strength between top and base loading of a 9' antenna is about 16 db (measured) on 75m, but Tom calculates 8db on 160. That's because he assumes the same current in the coil. Actually it's worse on 160 than 75." > 1. How tall the antenna is (never said); He said - 92" simulating mobile whip. > 2. How long the radials are (never said); Radials laid on the ground are non resonant, doesn't matter much, but there were enough of them (I remember him mentioning at least 32) > 3. How many turns in the coil (have to squint and count and hope); Coild is of good quality (aka Texas Bugcatcher), what is important that it was adjusted to bring antenna to 90 electr. degrees - RESONANCE. > 4. How long the coil is (you gotta guess); Same as 3, in each test, enough to resonante on band of test (40, 30, 80) > 5. What frequency this resonates at (well, actually it doesn't say it > resonates anywhere); Ham bands 40, 30, 80 and 160 is where they measured the currents. > 6. What the drive point Z is (as if that mattered) Not important as long as antenna is resonant on frequency in question. The power was adjusted to show 100 ma full scale on the bottom of the coil and read on the same type of meter on the top. > But we do know that some one can find > 7. The current into the coil and; > 8. The current out of the coil; > 9. which according to breathless reports makes all the difference in > the world, > Picture of REALITY vs. phasors, distributed baloney, pink electrons, bla, bla ... why it "could not be". More appropriate assesment would be "significant", which you can judge by his comment about 16 dB vs. 8 dB "calculated" by W8JI Anyone can duplicate the test and verify the results and claims, instead of displaying their ignorance of reality. > until > 10. I threw away that trash coil, replaced it with a distributed load > (aka shorted transmission line) and boosted the performance. > And you did that, and measured it, right? It has been proven in real life and measurements that "trash" coil performs better in the loaded Yagi design that loading stub (distributed load). It has been done, described and measured by at least three happy owners of modified KLM 2 or 3 el. loaded Yagis on 80. Improved gain and pattern, F/B. Interesting that the "problems" with loading coils and same current affcionados "know it" based on their (faulty) theories. W8JI attributes his mental state to others to "prove" his "right" which will end up being big egg in his face. Interesting, that question about loading stubs has "matured" to this also, instead of providing some answers for David. This is my last contribution to this thread. > 73's > Richard Clark, KB7QHC 73 Yuri, K3BU Article: 223591 of rec.radio.amateur.antenna From: "Jerry Martes" References: <1247p6p3cdursca@corp.supernews.com> <1145337537.742840.315710@j33g2000cwa.googlegroups.com> Subject: Re: Vertically Polorized Omni Slot Antenna Message-ID: Date: Tue, 18 Apr 2006 05:38:51 GMT wrote in message news:1145337537.742840.315710@j33g2000cwa.googlegroups.com... > So I guess the annular slot is the complement to a halo? Since I think of a halo as a loop in a plane parallel to the ground, it is difficult for me to make a comparison of it to a monopole antenna pattern. My suggestion would be for you to re-define your needs. There are some really good antenna designers contributing to this group. Article: 223592 of rec.radio.amateur.antenna From: "Yuri Blanarovich" References: <403942te0vdkte65fo3rsgcuga3t2pqtki@4ax.com> Subject: Re: fun with loading Message-ID: Date: Tue, 18 Apr 2006 10:24:07 -0400 OK one more time. We had argument about current in antenna loading coils, one bunch says it is different, another bunch says it is, has to be the same, no way can it be different. Instead of trying to verify the reality on real antennas, with real, typical hardware and measure it or show that there is something wrong with what we so far presented, we see "theoretical reasons" why it can't be and nitpicking on tangents leading to la-la land, instead of hitting the "meat" of the argument. Suit yourself. No one said that W9UCW did all the different band experiments with the same setup in the picture. He showed one picture, proof that current CAN be different at two ends of a loading coil, which W8JI and his worshippers claim it CAN NOT BE. Show us your setup, description and details showing that in all cases current IS ALWAYS (or almost) the SAME! There is really no point of arguing any more here. I will do the tests and with help of "our campers" we will present comprehensive article on the subject. I would like to thank you all, including "current nonbelievers" for their opposition, because they highlighted how much misinformation (50 years) and false "science" is out there and helped us to understand the depth and reasons for the current in the loading coil behavior, and especially for the need to set the record straight and help to improve the modeling of loaded antennas. The rest will be reported on my web site, which I will consolidate and bring up to date in the next few days at www.K3BU.us Then you can nitpick or provide critique. There is no point in arguing, when Cecil asks why is there higher current at the top of the coil and "unbelievers" are mum or keep rattling off their but, but, but... IT IS STANDING WAVE CURRENT and VOLTAGE along the resonator, get it? What's next? Denying that there is a daylight, when the sun is out? 73 + Yuri, K3BU Article: 223593 of rec.radio.amateur.antenna From: "Tom Donaly" Subject: Re: fun with loading References: <1145180243.458726.20590@i39g2000cwa.googlegroups.com> <1145227446.811948.31350@g10g2000cwb.googlegroups.com> <1145254113.447279.155260@z34g2000cwc.googlegroups.com> <38r6429t5021v46j4cb4a9047uf30bctr6@4ax.com> <1145303985.792386.114170@z34g2000cwc.googlegroups.com> <1145317172.067738.100500@i40g2000cwc.googlegroups.com> Message-ID: <8x71g.16786$tN3.2021@newssvr27.news.prodigy.net> Date: Tue, 18 Apr 2006 15:24:52 GMT K7ITM wrote: > :-) > > How nice it is to have modern instruments which cover a wide range of > frequencies in one simple measurement setup, display the results in any > of an array of formats, and even store the measurement results for use > in a variety of analysis programs. > > (Sometimes, it's even nicer to just escape from them altogether.) > > Cheers, > Tom > It's not quite so nice, though, when you develop a psychotic addiction to measuring which sends you to the poorhouse for buying expensive equipment, and to the therapist for treatment of your obsession. 73, Tom Donaly, KA6RUH Article: 223594 of rec.radio.amateur.antenna From: "Phil" Subject: M2 6 Meter Yegis Message-ID: Date: Tue, 18 Apr 2006 11:28:45 -0400 I am thinking for replacing my old Creative Design CL-6A 5 element 6 meter yagis with one of the M Squared antennas, either a 6M7, 6M7JHV, or a 6M2WLC. Does anyone know where there's any comparatiuve data on them or where there are product reviews on the 6M7 or 6M2WLC (the JHV was in QST a few years back)? Thanks Phil Finkle K6EID Article: 223595 of rec.radio.amateur.antenna From: "Yuri Blanarovich" References: <403942te0vdkte65fo3rsgcuga3t2pqtki@4ax.com> <931a421onp5m58fsnpe16kll01qv46t5d2@4ax.com> Subject: Re: fun with loading Message-ID: Date: Tue, 18 Apr 2006 12:56:58 -0400 OK, standby for our tests, measurements and data. Appears that you distrust anything we have argued, but W8JI and equal current believers need not to present similar data for your microscope. I will chronicle my experiments and provide data that you question. I am already washing up my 72 Buick LeSabre and cleaning antenna contacts, sharpening my instruments and hopefully have enough accurate numbers and answers for your questions. Helloooo! We are arguing current distribution in antenna loading coil. Is it always equal or can it vary? The rest is nitpicking and obfuscating the question in question. now really, really SK! 73 Yuri "Richard Clark" wrote in message news:931a421onp5m58fsnpe16kll01qv46t5d2@4ax.com... > On Tue, 18 Apr 2006 10:24:07 -0400, "Yuri Blanarovich" > wrote: > >>OK one more time. > > Hi Yuri, > > Of all things, "one more time" is boringly trivial. Put it in your > sweetheart diary, lock that sucker up, and put it back under your > pillow. You have not adequately specified anything, and your comments > about efficiency, performance and the rest (if in fact there was > anything else) are castles in the air. > >>There is really no point of arguing any more here. > > And yet this is the entire point of your having posted anything, isn't > it? > >>I will do the tests and >>with help of "our campers" we will present comprehensive article on the >>subject. > > Why would anyone believe in a future of full disclosure when you > obviously have such difficulty with simpler topics now? > > I offered very simple questions, all about very specific > characteristics of ONE antenna. This antenna was YOUR choice to > introduce the topic. This antenna was YOUR source of data for all > comments that flowed for 10000 postings ever after. You have had more > than 2 years to fill in the gaps about ONE antenna. The minimum among > these ANTENNA questions was: > > 1. How high? > > 2. What drive point Z? > > 3. What frequency for the combination of all elements? > > Now as to the particulars of loading: > > 1. How long a coil? > > 2. How many turns in that coil? > > 3. How long are the radials? > > Now as to your efficiency/performance claims: > > 1. What is the efficiency of a bare radiator without loading? > > 2. What is the efficiency of the loaded antenna you presented at your > page? > > 3. What is the performance criteria of a bare radiator? > > 4. What was the performance response of the loaded radiator you > presented at your page? > > We roll on to test proclamations about linear loading: > > 1. Let's simply skip this as being obviously tainted by so much > missing information as to be irresolvable from more old wives' tales. > > Everyone of these questions is easily answered with a simple number. > > Everyone of these questions is commonplace discussion for technical > examination. > > You have answered NONE of these questions. Or was it just one, 92 > inches tall? You couldn't even get that one right because the picture > ON YOUR PAGE obviously showed a bigger one! > > You apparently think you can treat us like fools and that this is > enough to prove: > >>What's next? Denying that there is a daylight, when the sun is out? > > Yuri, you don't have the horsepower to win the race of wits. > > 73's > Richard Clark, KB7QHC Article: 223596 of rec.radio.amateur.antenna From: "Jerry Martes" References: <1247p6p3cdursca@corp.supernews.com> <1145337537.742840.315710@j33g2000cwa.googlegroups.com> <1145374731.833215.126530@t31g2000cwb.googlegroups.com> Subject: Re: Vertically Polorized Omni Slot Antenna Message-ID: Date: Tue, 18 Apr 2006 17:15:25 GMT wrote in message news:1145374731.833215.126530@t31g2000cwb.googlegroups.com... > I'm not the one designing the antenna. I'd build a collinear. I'm > just interested in the properties of the annular slot. > > What I mean by "I guess the annular slot is the complement to a halo?" > is this: > > A halo as I know it is a half wave or so loop broken opposite the > feedpoint and in a plane parallel to the ground. It has an > omnidirectional azimuth pattern but radiates horizontally polarized > radiation. > > It seems that the annular slot is a slot in a plane parallel to the > ground, with an omnidirectional azimuth pattern, and vertically > polarized radiation. > > So, is an annular slot antenna a halo cut out of a sheet? > > 73, > Dan > N3OX Hi Dan I recognized that I responded improperly only after I'd sent that post about "you" being the original poster. I may learn to read sometime. But, back to your question about the annular slot. It is a circular slot cut in a plane, conducting surface. The original Annular Slot design concept may have involved itself with *top loading* of a monopole taken to the extreme. The radiator becomes a ring shaped slot. My problem with relating the Annular Slot with the Halo, is that the two antennas seem to be of different types. The annular slot does have the radiation pattern similar to 1/2 of that of the halo in free space. In the 1950's, the anular slot was used on most military aircraft for ~ 1GHz antennas since it does become flush with the conductive skin of the aircraft. I suspect there are better antennas in use today. Jerry Article: 223597 of rec.radio.amateur.antenna From: Butch Magee Subject: paint on antenna Date: Tue, 18 Apr 2006 12:40:10 -0500 Message-ID: <124a93qm7ohui1a@corp.supernews.com> We painted the heck out of them when I was in the Navy, 'course that was 47 years ago, but I bet they still do. Butch KF5DE Article: 223598 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: fun with loading References: <403942te0vdkte65fo3rsgcuga3t2pqtki@4ax.com> <931a421onp5m58fsnpe16kll01qv46t5d2@4ax.com> Message-ID: Date: Tue, 18 Apr 2006 18:24:47 GMT Yuri Blanarovich wrote: > standby for our tests, measurements and data. Yuri, I don't know what you are going to prove. W8JI's and W7EL's own measurements prove beyond any doubt that the current at each end of the coil is NOT equal. And the error they made in trying to measure phase using a signal with unchanging phase is more than obvious. What you are going to find is that the coil warps the current profile away from a pure cosine wave as is shown in Figure 3 at: http://www.k6mhe.com/n7ws/Loaded%20antennas.htm The delay through that coil is obviously NOT zero and the currents at the ends are obviously NOT equal. -- 73, Cecil http://www.qsl.net/w5dxp Article: 223599 of rec.radio.amateur.antenna From: Gene Fuller Subject: Re: Current across the antenna loading coil - from scratch References: <1144647060.456337.126840@e56g2000cwe.googlegroups.com> <1144708348.601210.298690@e56g2000cwe.googlegroups.com> <4nB_f.67497$Jd.30975@newssvr25.news.prodigy.net> <5nC_f.5711$YT1.592@bgtnsc04-news.ops.worldnet.att.net> <6ZF_f.64716$H71.32645@newssvr13.news.prodigy.com> Message-ID: <3_b1g.19794$az4.7266@bgtnsc04-news.ops.worldnet.att.net> Date: Tue, 18 Apr 2006 20:28:47 GMT Cecil, Why don't you go back and re-read that paper carefully. Pay particular attention to the part where the author says, with emphasis, that the magic formula only works when the coil is near or at resonance. Your extension to arbitrarily lower frequencies is pure nonsense. I guess you did not read my complete message. I pointed out the exact location in the paper where this limitation is explained. 73, Gene W4SZ Cecil Moore wrote: > Gene Fuller wrote: > >> I gave you a very specific reference to demonstrate your supposition >> was incorrect. You came back with nothing but, "Because I say so." You >> have not offered one shred of backing for your constant Vf argument. > > > Where the heck have you been? The equation for VF is equation (32) > > at: http://www.ttr.com/TELSIKS2001-MASTER-1.pdf > > Just before that equation for VF is a geometry test for the > coil in question. A 75m bugcatcher coil passes that test. > > The velocity factor equation contains helix diameter, turns > per unit length, and wavelength. If we keep those three > quantities constant, the VF of a coil should remain constant > while varying the length of the coil. > > The problem encountered previously was we kept the coil length > constant while varying the frequency. That does change the VF. > But this time we are keeping frequency constant. Article: 223600 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: Coax Question Date: Tue, 18 Apr 2006 14:42:10 -0700 Message-ID: <124an9msrp204c3@corp.supernews.com> References: The most harmful thing to most plastics outdoors is sunlight. I've had some PE jacketed coax outside for many years without noticeable degradation. However, it gets buried in the grass after a couple of years so doesn't get a whole lot of direct sun. Clear PE will deteriorate fairly quickly, but black coloring prevents penetration of the UV light, so I'd expect black PE jacketed cable to last a very long time. Rain, snow, and temperature extremes aren't a problem. Roy Lewallen, W7EL Robert11 wrote: > Hello: > > Have started running cvoax from a receve-only antenna to the house. > The coax has a Polyethylene (PE) Outer jacket. > With this PE jacket, it's upposed to be buriable. > > It's becoming a real job for me at my age to dig a slit trench, even a > shallow one. > But, I can easily just lay the coax on the surface, without any reql danger > of anyone > stepping on it, etc. It's in a pretty out of the way area. > > I realize that burying it is undoubtedly best, but in a practical > sense, how well does a PE outer jacket stand up if just laying on the ground > ? > Would be subjected, of course, to rain, and also buried in snow during the > winter. > > Again, it's receive only. > > Thanks, > Bob > > Article: 223601 of rec.radio.amateur.antenna From: "Tom Donaly" Subject: Re: fun with loading References: <403942te0vdkte65fo3rsgcuga3t2pqtki@4ax.com> <931a421onp5m58fsnpe16kll01qv46t5d2@4ax.com> Message-ID: <5pe1g.3040$Lm5.140@newssvr12.news.prodigy.com> Date: Tue, 18 Apr 2006 23:14:09 GMT Cecil Moore wrote: > Yuri Blanarovich wrote: > >> standby for our tests, measurements and data. > > > Yuri, I don't know what you are going to prove. W8JI's > and W7EL's own measurements prove beyond any doubt that > the current at each end of the coil is NOT equal. And > the error they made in trying to measure phase using > a signal with unchanging phase is more than obvious. > > What you are going to find is that the coil warps the > current profile away from a pure cosine wave as is > shown in Figure 3 at: > > http://www.k6mhe.com/n7ws/Loaded%20antennas.htm > > The delay through that coil is obviously NOT zero and > the currents at the ends are obviously NOT equal. How do you know it's a "pure cosine wave," Cecil? 73, Tom Donaly, KA6RUH Article: 223602 of rec.radio.amateur.antenna Date: Tue, 18 Apr 2006 18:59:47 -0500 From: Tom Ring Subject: Re: fun with loading References: <403942te0vdkte65fo3rsgcuga3t2pqtki@4ax.com> <931a421onp5m58fsnpe16kll01qv46t5d2@4ax.com> Message-ID: <44457d74$0$76686$39cecf19@news.twtelecom.net> Richard Clark wrote: > > You have answered NONE of these questions. Or was it just one, 92 > inches tall? You couldn't even get that one right because the picture > ON YOUR PAGE obviously showed a bigger one! > > You apparently think you can treat us like fools and that this is > enough to prove: > > >>What's next? Denying that there is a daylight, when the sun is out? > > > Yuri, you don't have the horsepower to win the race of wits. > > 73's > Richard Clark, KB7QHC If he will just post the plans to duplicate the antenna, it would give the rest of us something to test. That would be way too easy, I guess. tom K0TAR Article: 223603 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Current across the antenna loading coil - from scratch References: <1144647060.456337.126840@e56g2000cwe.googlegroups.com> <1144708348.601210.298690@e56g2000cwe.googlegroups.com> <4nB_f.67497$Jd.30975@newssvr25.news.prodigy.net> <5nC_f.5711$YT1.592@bgtnsc04-news.ops.worldnet.att.net> <6ZF_f.64716$H71.32645@newssvr13.news.prodigy.com> <3_b1g.19794$az4.7266@bgtnsc04-news.ops.worldnet.att.net> Message-ID: Date: Wed, 19 Apr 2006 00:14:07 GMT Gene Fuller wrote: > Why don't you go back and re-read that paper carefully. Pay particular > attention to the part where the author says, with emphasis, that the > magic formula only works when the coil is near or at resonance. A 75m bugcatcher coil is self resonant at 6.6 MHz. That's near 4 MHz. Where is all your irrationality coming from? -- 73, Cecil http://www.qsl.net/w5dxp Article: 223604 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: fun with loading References: <403942te0vdkte65fo3rsgcuga3t2pqtki@4ax.com> <931a421onp5m58fsnpe16kll01qv46t5d2@4ax.com> <5pe1g.3040$Lm5.140@newssvr12.news.prodigy.com> Message-ID: Date: Wed, 19 Apr 2006 00:16:08 GMT Tom Donaly wrote: > Cecil Moore wrote: >> What you are going to find is that the coil warps the >> current profile away from a pure cosine wave ... > > How do you know it's a "pure cosine wave," Cecil? Because Kraus says so? -- 73, Cecil http://www.qsl.net/w5dxp Article: 223605 of rec.radio.amateur.antenna From: ml Subject: Re: Coax Question References: <4445582D.1064B76A@shaw.ca> Message-ID: Date: Wed, 19 Apr 2006 00:18:07 GMT the other way to burry it, rather than dig a slit, perhaps you can get a bit of topsoil and just burry it slightly and pack it down after it will 'seem ' to blend in a bit faster i dunno just a idea obv you don't want too much extra dirt to create hazard or eyesore but just a little to soften the edges so to speak In article <4445582D.1064B76A@shaw.ca>, Irv Finkleman wrote: > Robert11 wrote: > > > > Hello: > > > > Have started running cvoax from a receve-only antenna to the house. > > The coax has a Polyethylene (PE) Outer jacket. > > With this PE jacket, it's upposed to be buriable. > > > > It's becoming a real job for me at my age to dig a slit trench, even a > > shallow one. > > But, I can easily just lay the coax on the surface, without any reql danger > > of anyone > > stepping on it, etc. It's in a pretty out of the way area. > > > > I realize that burying it is undoubtedly best, but in a practical > > sense, how well does a PE outer jacket stand up if just laying on the ground > > ? > > Would be subjected, of course, to rain, and also buried in snow during the > > winter. > > > > Again, it's receive only. > > > > Thanks, > > Bob > > I've had coax running though my yard for the past five or six years. It was > just laid across the grass. Gradually it worked it's way out of sight and > show's no sign of deterioration (electrically). We use the yard a lot, I > mow over it, water it, herbicide it, and everything. It survives the harsh > Alberta winters, wet springs, and all. It was just some RG-213 that I picked > up at a flea market!!!! > > Irv VE6BP Article: 223606 of rec.radio.amateur.antenna From: ml Subject: ferrious vs non ferric Message-ID: Date: Wed, 19 Apr 2006 00:24:27 GMT was hoping to get a rough idea of how much a non ferric metal would effect a existing antenna if brought extreemly close I can kinda estimate what a typical ferrious /metal object might do, but say if an exact shaped no ferrious object was brought equally near what would be the effect compartively speaking Article: 223607 of rec.radio.amateur.antenna From: "Tom Donaly" Subject: Re: Current across the antenna loading coil - from scratch References: <1144647060.456337.126840@e56g2000cwe.googlegroups.com> <4nB_f.67497$Jd.30975@newssvr25.news.prodigy.net> <5nC_f.5711$YT1.592@bgtnsc04-news.ops.worldnet.att.net> <6ZF_f.64716$H71.32645@newssvr13.news.prodigy.com> <3_b1g.19794$az4.7266@bgtnsc04-news.ops.worldnet.att.net> Message-ID: Date: Wed, 19 Apr 2006 00:54:37 GMT Cecil Moore wrote: > Gene Fuller wrote: > >> Why don't you go back and re-read that paper carefully. Pay particular >> attention to the part where the author says, with emphasis, that the >> magic formula only works when the coil is near or at resonance. > > > A 75m bugcatcher coil is self resonant at 6.6 MHz. That's > near 4 MHz. Where is all your irrationality coming from? 4 Mhz is not 6.6 Mhz. You're stretching the truth again, Cecil. Gene is right. Why not just give up. You're not going to make anything true just by repeating it over and over again. 73, Tom Donaly, KA6RUH Article: 223608 of rec.radio.amateur.antenna From: "Tom Donaly" Subject: Re: fun with loading References: <403942te0vdkte65fo3rsgcuga3t2pqtki@4ax.com> <931a421onp5m58fsnpe16kll01qv46t5d2@4ax.com> <5pe1g.3040$Lm5.140@newssvr12.news.prodigy.com> Message-ID: Date: Wed, 19 Apr 2006 00:58:20 GMT Cecil Moore wrote: > Tom Donaly wrote: > >> Cecil Moore wrote: >> >>> What you are going to find is that the coil warps the >>> current profile away from a pure cosine wave ... >> >> >> How do you know it's a "pure cosine wave," Cecil? > > > Because Kraus says so? That's interesting. It means we don't need to use NEC any more. 73, Tom Donaly, KA6RUH Article: 223609 of rec.radio.amateur.antenna Date: Tue, 18 Apr 2006 21:37:35 -0400 From: jawod Subject: antennas and rain Message-ID: <828f4$4445947d$453d9423$16800@FUSE.NET> I think I read in this newsgroup that a ham in the PNW waxed his dipole to keep the rain off. I couldn't tell whether it was just a joke? In an area notorious for lots of rain, do hams in the Northwest really wax their antennas? Even when waxed, what is the effect of rain/water on dipole chararacteristics? John AB8WH Article: 223610 of rec.radio.amateur.antenna From: Gene Fuller Subject: Re: Current across the antenna loading coil - from scratch References: <1144647060.456337.126840@e56g2000cwe.googlegroups.com> <4nB_f.67497$Jd.30975@newssvr25.news.prodigy.net> <5nC_f.5711$YT1.592@bgtnsc04-news.ops.worldnet.att.net> <6ZF_f.64716$H71.32645@newssvr13.news.prodigy.com> <3_b1g.19794$az4.7266@bgtnsc04-news.ops.worldnet.att.net> Message-ID: Date: Wed, 19 Apr 2006 01:57:58 GMT Cecil Moore wrote: > Gene Fuller wrote: > >> Why don't you go back and re-read that paper carefully. Pay particular >> attention to the part where the author says, with emphasis, that the >> magic formula only works when the coil is near or at resonance. > > > A 75m bugcatcher coil is self resonant at 6.6 MHz. That's > near 4 MHz. Where is all your irrationality coming from? Cecil, I guess you can't keep up with your fairy tales. The exact quote from your message on April 11, at 9:57 am is copied below. I don't see anything about a bugcatcher coil. Instead there is some un-described coil stock that requires 37 extra turns in addition to the starting 32 turns to achieve self-resonance at 4 MHz. Since the Corum paper highlighted the limitation for applicability of the magic formula it is possible he thought that the limitation might be important. However, with your superior intellect it is fully justifiable to go ahead and accept only those portions of his paper that support your preconceived notions. I suppose whatever number you determine will still fall within your 59% standard of precision. 73, Gene W4SZ [quote] *************************************************** Here's a more valid procedure for determining the delay through a coil. Changing nothing except the number of turns, add turns until the coil is self- resonant at the frequency of use. Frequency doesn't change. Coil diameter doesn't change. Turns per inch doesn't change. The *ONLY* thing that changes is the length of the coil. At self-resonance, we *know* the longer coil is 90 degrees long. *************************************************** Take that same 32 turn coil and keeping everything the same, add turns to the coil until it is self-resonant. We haven't changed the frequency, the diameter, or the turns per inch. All we have done is add 37 turns to the original 32 turn coil to make the self-resonant frequency equal to 4 MHz with 69 turns. SINCE WE HAVEN'T CHANGED THE FREQUENCY, WE KNOW THAT THE VELOCITY FACTOR OF THE COIL HAS NOT CHANGED. In the velocity factor equation, the only variables are coil diameter, turns per inch, and wavelength. NONE OF THOSE VARIABLES ARE CHANGED ABOVE. So we know that 69 turns makes that coil stock self-resonant at 4 MHz. That would make the phase shift through 32 turns equal to 42 degrees, making our above 10 degree assumption false. 42 degrees is probably fairly close to the actual value. The velocity factor for that coil stock calculates out to be 0.023 on 4 MHz. [end quote] Article: 223611 of rec.radio.amateur.antenna From: "David G. Nagel" Subject: Re: antennas and rain Date: Tue, 18 Apr 2006 22:19:02 -0500 Message-ID: <124bb1keret5s0e@corp.supernews.com> References: <828f4$4445947d$453d9423$16800@FUSE.NET> Richard Clark wrote: > On Tue, 18 Apr 2006 21:37:35 -0400, jawod wrote: > > >>In an area notorious for lots of rain, do hams in the Northwest really >>wax their antennas? > > > No, it inhibits moss. > > 73's > Richard Clark, KB7QHC, Seattle (rain city) Only on the south side.... Dave WD9BDZ Article: 223612 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: antennas and rain Date: Tue, 18 Apr 2006 20:44:39 -0700 Message-ID: <124bchbqripdgae@corp.supernews.com> References: <828f4$4445947d$453d9423$16800@FUSE.NET> Richard Clark wrote: > On Tue, 18 Apr 2006 21:37:35 -0400, jawod wrote: > >> In an area notorious for lots of rain, do hams in the Northwest really >> wax their antennas? > > No, it inhibits moss. Only QRPers need it for that -- the big guns just burn the moss off. Roy Lewallen, W7EL Article: 223613 of rec.radio.amateur.antenna From: "Sal M. Onella" References: <6WZ%f.557$QP4.244@fed1read12> Subject: Re: Mag Mount on aluminum ? Message-ID: Date: Tue, 18 Apr 2006 21:10:05 -0700 "Buck" wrote in message news:c8v542lg9n1alb2sf876f8oba2vb50tk7n@4ax.com... > On Fri, 14 Apr 2006 20:39:46 -0700, "Sal M. Onella" > wrote: > >I was able to make a magmount work OK with only a steel TV tray. < snip > > Try a pizza pan 'At'sa some good idea you got! Article: 223614 of rec.radio.amateur.antenna From: "Sal M. Onella" References: <124a93qm7ohui1a@corp.supernews.com> <32ga42p9fe1qc6b938ojr3sh3c7nv98jg8@4ax.com> Subject: Re: paint on antenna Message-ID: Date: Tue, 18 Apr 2006 21:29:22 -0700 "KenW" wrote in message news:32ga42p9fe1qc6b938ojr3sh3c7nv98jg8@4ax.com... > On Tue, 18 Apr 2006 12:40:10 -0500, Butch Magee > wrote: > > >We painted the heck out of them when I was in the Navy, 'course that was > >47 years ago, but I bet they still do. > > > >Butch KF5DE > Did that ages ago. Didn't know that old paint had real aluminum in it > Antenna didn't work very well !!!!!!!!!!!!!! > > > ken...w2bdp We paint them now, too. The HF whips are all tapered fiberglass shafts (some two-piece) with a single conductor in the center for the radiating element. The resin would be eaten up by the sunlight without painting, but it's special paint that is transparent to RF. There's a need for quite a lot of it, considering all the radomes on the ships for satcom and radar. (The really big ones are just "out there" in the elements but many antennas are in domes.) Radar Absorbent Material (RAM) is used a lot, and it has to be preserved with antenna paint, too; Regular paint on RAM would reflect just like whatever surface the RAM is applied to, defeating the purpose.