Article: 96822 of rec.radio.amateur.homebrew Subject: Re: 4CX250B 2m linear circuit? (Class C ideally!) From: Allan Butler Date: Sun, 12 Mar 2006 22:05:06 -0600 Message-ID: <1142222573_37@64triton.net> References: Samuel Hunt wrote: > Hi all. > > I'm trying to find a good circuit for a Class C 4CX250B linear. > > I've found a few for multiple valves in Class A, but I'm after just a > simple circuit that shows a 4CX250B linear for 2m with Class C biasing. > > Idea is to use it for a little project where I want to run about 100W, but > run it cleanly without all the RF hash that transistor amps give. > > > Can anyone point me in the right direction? > > Also, how would you go about varying the RF power output on a 4CX250B > linear in class C? Is it by varying the 1.2kV supply voltage, which would > make sense, or is there some other recommended way? > > > Sam Sam: If you want to run an RF amp in a linear manner then one cannot bias the amp in class C. Class C is not a linear mode of operation and will give all kinds of trash if running in SSB. Now if you are running either CW or FM, then you can run a class C amplifier. The Most linear class of amplifier operation in the classic modes is class A mode. This mode means the active device is always conducting even when the input is not being fed any signal. In an ideal world efficiency of class A is only going to be 25 percent. Most amateur class amplifiers run in a mode that is either ABone or ABtwo. I can't recall the differences between the two at the moment but they are clean under normal operation and don't put out a lot of noise. ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- Article: 96823 of rec.radio.amateur.homebrew From: Nedlar Subject: Re: Optical Communications? RSCB Irrelevance? (Was : Re: The smallest Baird Televisor?) Date: Mon, 13 Mar 2006 10:29:15 +0000 Message-ID: <66ia12hmnegvqp02shs20ganuqmp01an87@4ax.com> References: <1142099027.152408.11300@i39g2000cwa.googlegroups.com> <1142146185.518102.243580@j52g2000cwj.googlegroups.com> <6cr712du3m5q1vg49fhjfm0n21bst29sdk@4ax.com> On Sun, 12 Mar 2006 23:15:50 +0000, Spike the coward wrote: > >Do your neighbours know you have an excessive interest in the school >holidays? My only interest in the holidays are a deep concern for your welfare. I know that you, being paedophobic, suffer greatly. If we could now get you to understand what ' I can't think of anything else' means, then that would be real progress. What is it about the above sentence that confuses you? Post the article if your man enough. Article: 96824 of rec.radio.amateur.homebrew From: Spike Subject: Re: Optical Communications? RSCB Irrelevance? (Was : Re: The smallest Baird Televisor?) Date: Mon, 13 Mar 2006 10:48:58 +0000 Message-ID: References: <1142099027.152408.11300@i39g2000cwa.googlegroups.com> <1142146185.518102.243580@j52g2000cwj.googlegroups.com> <6cr712du3m5q1vg49fhjfm0n21bst29sdk@4ax.com> <66ia12hmnegvqp02shs20ganuqmp01an87@4ax.com> Nedlar The Simpleton Simon wrote: >On Sun, 12 Mar 2006 23:15:50 +0000, Spike the >coward wrote: > >>Do your neighbours know you have an excessive interest in the school >>holidays? > >My only interest in the holidays are a deep concern for your welfare. >I know that you, being paedophobic, suffer greatly. Nice try at blame-shifting, but your excessive interest in the timing of school holidays is entirely down to you, and is a matter of public record. Perhaps you'd like to ponder the implications of that. Don't use me as a cover. >If we could now get you to understand what ' I can't think of anything >else' means, then that would be real progress. > >What is it about the above sentence that confuses you? > >Post the article if your man enough. If you aren't careful someone will tell your Care in the Community Social Worker how naughty you've been. You won't like that, she won't wipe the egg from your face. No throwing away of a fine receiver here due to 'nerves', fettling, or missing pages from the manual. ROFLMAO. In fact, it directly follows the Gospel According to Gareth, in his (still unqualified and therefore dangerous) 'repair with gusto' creed; something he has admitted failing in the past. ROFLMAO. from Aero Spike Article: 96825 of rec.radio.amateur.homebrew From: Nedlar Subject: Re: Optical Communications? RSCB Irrelevance? (Was : Re: The smallest Baird Televisor?) Date: Mon, 13 Mar 2006 11:08:05 +0000 Message-ID: References: <1142099027.152408.11300@i39g2000cwa.googlegroups.com> <1142146185.518102.243580@j52g2000cwj.googlegroups.com> <6cr712du3m5q1vg49fhjfm0n21bst29sdk@4ax.com> <66ia12hmnegvqp02shs20ganuqmp01an87@4ax.com> On Mon, 13 Mar 2006 10:48:58 +0000, Spike wrote: > >Nice try at blame-shifting, but your excessive interest in the timing >of school holidays is entirely down to you, and is a matter of public >record. Perhaps you'd like to ponder the implications of that. The blame shifting is entirely yours. It was your original article that mentioned problems during school holidays. Perhaps you'd like to ponder on that! Don't use me as a cover. Still not man enough to post the article eh? Article: 96826 of rec.radio.amateur.homebrew From: Spike Subject: Re: Optical Communications? RSCB Irrelevance? (Was : Re: The smallest Baird Televisor?) Date: Mon, 13 Mar 2006 11:54:53 +0000 Message-ID: References: <1142146185.518102.243580@j52g2000cwj.googlegroups.com> <6cr712du3m5q1vg49fhjfm0n21bst29sdk@4ax.com> <66ia12hmnegvqp02shs20ganuqmp01an87@4ax.com> Nedlar wrote, before the nurse took away his computer: >On Mon, 13 Mar 2006 10:48:58 +0000, Spike >wrote: > >> >>Nice try at blame-shifting, but your excessive interest in the timing >>of school holidays is entirely down to you, and is a matter of public >>record. Perhaps you'd like to ponder the implications of that. > >The blame shifting is entirely yours. It was your original article >that mentioned problems during school holidays. Perhaps you'd like to >ponder on that! That was very poor...is the medication wearing off? >Don't use me as a cover. > >Still not man enough to post the article eh? Still not technical enough to repost one of your own articles? If you aren't careful someone will tell your Care in the Community Social Worker how naughty you've been. You won't like that, she won't wipe the egg from your face. No throwing away of a fine receiver here due to 'nerves', fettling, or missing pages from the manual. ROFLMAO. In fact, it directly follows the Gospel According to Gareth, in his (still unqualified and therefore dangerous) 'repair with gusto' creed; something he has admitted failing in the past. ROFLMAO. from Aero Spike Article: 96827 of rec.radio.amateur.homebrew From: =?ISO-8859-1?Q?Per-=C5ke_Andersson?= Subject: Re: Wainwright Mini-Mounts Date: Mon, 13 Mar 2006 12:57:12 +0100 Message-ID: References: John A wrote: > Does anyone know of a UK source for "Wainwright Mini-mounts"? These are > small PCBs made in Germany by WMM GmbH (no web-site or email!), laid out to > take an IC, with tracks from each IC pad taken out to the edge of the PCB - > very useful for prototyping with TSSOP devices it seems. > > If they sound interesting, see: > > http://www.rdi-wainwright.com/ > > which is the site of the US agent - $100 min order! > > John > > > Could be the same as http://www.wainwright-filters.com/ There adress is andechs (See Impressum at homepage) /Per-Ake -- Remove "extra" in my e-mail Article: 96828 of rec.radio.amateur.homebrew From: Nedlar Subject: Re: Optical Communications? RSCB Irrelevance? (Was : Re: The smallest Baird Televisor?) Date: Mon, 13 Mar 2006 12:42:05 +0000 Message-ID: References: <6cr712du3m5q1vg49fhjfm0n21bst29sdk@4ax.com> <66ia12hmnegvqp02shs20ganuqmp01an87@4ax.com> On Mon, 13 Mar 2006 11:54:53 +0000, Spike wrote: > >That was very poor...is the medication wearing off? You're getting more childish by the hour. No wonder the kids hate you. ( It's that word again, sorry it frightens you). Still not man enough to post the article eh? Article: 96829 of rec.radio.amateur.homebrew From: Allison-nospam@nouce.bellatlantic.net Subject: Re: 4CX250B 2m linear circuit? (Class C ideally!) Message-ID: <7vra12hq3hdnc903gard6ae00ni4d7r794@4ax.com> References: Date: Mon, 13 Mar 2006 13:29:59 GMT On Sun, 12 Mar 2006 11:30:43 +0000 (UTC), "Samuel Hunt" wrote: >Hi all. > >I'm trying to find a good circuit for a Class C 4CX250B linear. > >I've found a few for multiple valves in Class A, but I'm after just a simple >circuit that shows a 4CX250B linear for 2m with Class C biasing. > >Idea is to use it for a little project where I want to run about 100W, but >run it cleanly without all the RF hash that transistor amps give. > > >Can anyone point me in the right direction? > >Also, how would you go about varying the RF power output on a 4CX250B linear >in class C? Is it by varying the 1.2kV supply voltage, which would make >sense, or is there some other recommended way? > > >Sam There are several things here. Well designed and operated transistor amps are clean. if transistor amps are "dirty" there are design issues (spurious oscillation is common is poor designs). Class C tube operation is simply a bias and drive change and for any 4cx250 the circuit will remain the same with maybe some variation in the output network tuning for optimum results. For good clean linear operation of 4CX250 the Anode voltage should be as close as possble to 2kv and screen voltages stiffly regulated. Use plenty of air to keep it cool. For FM use Class C is efficient and works. For AM and SSB you must run as linear modes or the distortion will be excessive. One exception, for AM plate/screen modulated final that tube can be run class C(old style big modulation transformer AM). A 4cx250B plate modulated is good for around 60W(carrier) with heavy cooling and must run with reduced anode voltage to avoid arc overs. The 4CX250 was a VHF tube of choice for FM and constant carrier operations as well as pulsed (radar). For HF plate modulated or linear operation a 4-400 or 3-500 will put out far more power. If you are getting noise on recieve then the switching is not removing bias/power (transistor) or applying cutoff bias (tube). IF you want linear operation then the tube (or transistors) must be correctly biased for the amplifier topology, class B or AB2 for push-pull designs and AB1 or AB2 for single ended. Allison Article: 96830 of rec.radio.amateur.homebrew From: Roberto IZ5FCY Subject: GG Tetrode/Pentode QRO Date: Mon, 13 Mar 2006 15:05:04 +0100 Message-ID: <1afj8ab1gogi.qjys8f3ucsch$.dlg@40tude.net> Hello to everybody. I would want to use a pair or quad tetrode (4-400a or 4cx250/350) as GG triode for AB/C class operations. I don't remember where I have read that only the control grid had physically push to ground, while the others grid(s) was electrically floating and connected to ground through of the capacitors.... Can you help me with schemas, links and suggestions? Many thanks in advance..and sorry for bandwidht... Roberto IZ5FCY -- 73's de IZ5FCY Roberto Article: 96831 of rec.radio.amateur.homebrew From: "Bill Turner" Subject: Re: GG Tetrode/Pentode QRO References: <1afj8ab1gogi.qjys8f3ucsch$.dlg@40tude.net> Message-ID: <4415a997$1_1@newsfeed.slurp.net> Date: 13 Mar 2006 12:19:19 -0500 ORIGINAL MESSAGE: > I don't remember where I have read that only the control grid had > physically push to ground, while the others grid(s) was electrically > floating and connected to ground through of the capacitors.... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The control grid should be connected directly to ground but never allow the other grids to float. They must either be connected to a standard bias supply or grounded themselves. If they are floating, they will pick up a charge and do things you don't want them to do. :-) Connecting all grids to ground was a common practice in the old days but is rarely done anymore, due I believe to bad linearity. If you're only doing CW, FM or RTTY, linearity is not an issue and it should work fine that way. Bill, W6WRT Article: 96832 of rec.radio.amateur.homebrew From: Roberto IZ5FCY Subject: Re: GG Tetrode/Pentode QRO References: <1afj8ab1gogi.qjys8f3ucsch$.dlg@40tude.net> Date: Mon, 13 Mar 2006 21:29:35 +0100 Message-ID: > AFAIK a tetrode in grounded grid doesn't give you much more (if any) > gain than a triode in grounded grid, but you still need all the special > care and feeding of the screen. I agree with you opinion. > So why not just use triodes? My experiences are only in triode PA and I have a lot of tetrodes and pentodes "unemployed" :-))) > Better yet, why not use the tetrodes in common-cathode service, and get > 1000 watts out for 1-10 watts in? Sure, but I don't have experience in tetrode or pentode PA and the screen grid managenement, isn't a walking... In all know books and websites I don't find a valid explaination of this matter.... Thanks!! -- 73's de IZ5FCY Roberto Article: 96833 of rec.radio.amateur.homebrew From: Roberto IZ5FCY Subject: Re: GG Tetrode/Pentode QRO References: <1afj8ab1gogi.qjys8f3ucsch$.dlg@40tude.net> <4415a997$1_1@newsfeed.slurp.net> Date: Mon, 13 Mar 2006 21:30:15 +0100 Message-ID: <1ec0b1uuy54a9.gfut7q4gm29g.dlg@40tude.net> > The control grid should be connected directly to ground but never allow > the other grids to float. They must either be connected to a standard > bias supply or grounded themselves. If they are floating, they will > pick up a charge and do things you don't want them to do. :-) > > Connecting all grids to ground was a common practice in the old days > but is rarely done anymore, due I believe to bad linearity. If you're > only doing CW, FM or RTTY, linearity is not an issue and it should work > fine that way. > > Bill, W6WRT Thanks Bill... -- 73's de IZ5FCY Roberto Article: 96834 of rec.radio.amateur.homebrew From: "DPhil" References: Subject: Re: Wainwright Mini-Mounts Date: Mon, 13 Mar 2006 22:52:55 -0000 Message-ID: <4415f73d_2@mk-nntp-1.news.uk.worldonline.com> Try www.rapidelectronics.co.uk look under PCB Equipment described as surface mount development boards Phil G8AAE "John A" wrote in message news:dv0rmo$uoa$1@newsg2.svr.pol.co.uk... > Does anyone know of a UK source for "Wainwright Mini-mounts"? These are > small PCBs made in Germany by WMM GmbH (no web-site or email!), laid out to > take an IC, with tracks from each IC pad taken out to the edge of the PCB - > very useful for prototyping with TSSOP devices it seems. > > If they sound interesting, see: > > http://www.rdi-wainwright.com/ > > which is the site of the US agent - $100 min order! > > John > > > Article: 96835 of rec.radio.amateur.homebrew Date: Tue, 14 Mar 2006 00:59:27 +0200 From: Risto Tiilikainen Subject: Re: 4CX250B 2m linear circuit? (Class C ideally!) References: Message-ID: <4415f851$0$7477$39db0f71@news.song.fi> Ken Scharf kirjoitti: > >> >> >> > Oxymoron. Class C is NOT linear! > True > Now if you want to amplify CW or FM signals, class > C is fine. For AM or SSB signals you want class A, AB or B. > For this tube the grid #1 bias, grid #2 voltage and grid #1 > drive (signal input) are different as you change class of > operation. (Mostly the screen and plate voltages can remain > the same and just change the resting plate current with the > bias and don't apply more than a specific signal level so > your max plate current isn't exceeded.) > Hi Class C isn't fine. Class C is producing a lot of harmonics Specially odd ones are bad. I don't recomment class C elsewhere but for transistor FM use in VHF and UHF Maybe also for KISS QRP in HF CW 73 , Risto OH2BT Article: 96836 of rec.radio.amateur.homebrew From: Spike Subject: Re: Optical Communications? RSCB Irrelevance? (Was : Re: The smallest Baird Televisor?) Date: Mon, 13 Mar 2006 23:17:38 +0000 Message-ID: References: <6cr712du3m5q1vg49fhjfm0n21bst29sdk@4ax.com> <66ia12hmnegvqp02shs20ganuqmp01an87@4ax.com> Nedlar wrote: >On Mon, 13 Mar 2006 11:54:53 +0000, Spike >wrote: > >>That was very poor...is the medication wearing off? >You're getting more childish by the hour. No wonder the kids hate you. >( It's that word again, sorry it frightens you). > >Still not man enough to post the article eh? Still not man enough to repost one of your technical articles? I thought not. from Aero Spike Article: 96837 of rec.radio.amateur.homebrew From: "Reg Edwards" Subject: Re: GG Tetrode/Pentode QRO Date: Tue, 14 Mar 2006 02:59:28 +0000 (UTC) Message-ID: References: <1afj8ab1gogi.qjys8f3ucsch$.dlg@40tude.net> How to adjust DC grid bias, screen and plate voltages, RF grid-drive volts, to provide a given plate-current operating angle, is shown in program OPANGLE3. It is the plate current operating angle which decides which condition the amplifier is operated under. Program OPANGLE3 covers covers class-AB, B and C conditions. Download now from website below. ---- ........................................................... Regards from Reg, G4FGQ For Free Radio Design Software go to http://www.btinternet.com/~g4fgq.regp ........................................................... Article: 96838 of rec.radio.amateur.homebrew From: ken scharf Subject: Re: GG Tetrode/Pentode QRO References: <1afj8ab1gogi.qjys8f3ucsch$.dlg@40tude.net> Message-ID: Date: Mon, 13 Mar 2006 22:04:19 -0500 Tim Wescott wrote: > Roberto IZ5FCY wrote: > >> Hello to everybody. >> I would want to use a pair or quad tetrode (4-400a or 4cx250/350) as GG >> triode for AB/C class operations. >> >> I don't remember where I have read that only the control grid had >> physically push to ground, while the others grid(s) was electrically >> floating and connected to ground through of the capacitors.... >> >> Can you help me with schemas, links and suggestions? >> >> Many thanks in advance..and sorry for bandwidht... >> >> >> Roberto IZ5FCY >> > AFAIK a tetrode in grounded grid doesn't give you much more (if any) > gain than a triode in grounded grid, but you still need all the special > care and feeding of the screen. > > So why not just use triodes? > > Better yet, why not use the tetrodes in common-cathode service, and get > 1000 watts out for 1-10 watts in? > By connecting BOTH grids of a 4-400A or similar tube to ground you are creating a high mu triode out of a tetrode/pentode/beampower tube. Nothing wrong with that, but triodes made specificly for the purpose do work better. Now if you happen to have gotten the tetrodes surplus, or they are already in the junk box, use them, they make good grounded grid amplifiers. The "triode" grounded grid connection does not require neutralization, bias, or screen power. It DOES require more driving power. You can also apply normal grid and screen voltages but ground the grids (for RF) with capacitors and apply drive to the cathode as in grounded grid. This is called "cathode driven". A cathode driven tetrode requires no neutralization and needs less drive than a true grounded grid amp, but more drive than grounded cathode (grid driven). BTW not all tetrodes can be driven in true grounded grid. The 4cx250 for example, can ONLY be used in cathode driven or grid driven service. If you try to run it as true grounded grid you will MELT the grids! Article: 96839 of rec.radio.amateur.homebrew From: Eamon Skelton Subject: Re: RF power transistor - CM10-12A datasheet, and stock Message-ID: References: <1142313821.705029.197960@i39g2000cwa.googlegroups.com> Date: Tue, 14 Mar 2006 08:24:24 +0000 On Mon, 13 Mar 2006 21:23:41 -0800, MarkAren wrote: > Hi Guys, > > Can anyone help with a full data sheet and an idea where I might be able > to buy one without getting charged the earth. > > Thanks, > > Mark. datasheetarchive.com list the MRF641 as a possible substitute. The MRF641 datasheet is readily available. A comparison with the specs below shows that they are quite similar but not identical. The following specs are also from datasheetarchive.com Part Number = CM10-12A Description = Bipolar NPN UHF-Microwave Transisitor Manufacturer = Various V(BR)CBO (V) = 36 I(C) Abs.(A) Collector Current = 2.5 Absolute Max. Power Diss. (W) = 35 Power Gain Min. (dB) = 7 @V(CE) (V) (Test Condition) = 12 @Freq. (Hz) (Test Condition) = 470M @I(C) (A) (Test Condition) = 10 @V(CE) (V) (Test Condition) = 12 @Freq. (Hz) (Test Condition) = 470M Semiconductor Material = Silicon Package = SOT-119var 73, Ed. EI9GQ. -- Linux 2.6.15 Remove 'X' to reply by e-mail. Yes, my username really is: nospam Article: 96840 of rec.radio.amateur.homebrew From: Roberto IZ5FCY Subject: Re: GG Tetrode/Pentode QRO References: <1afj8ab1gogi.qjys8f3ucsch$.dlg@40tude.net> Date: Tue, 14 Mar 2006 09:50:38 +0100 Message-ID: > BTW not all tetrodes can be driven in true grounded grid. The 4cx250 > for example, can ONLY be used in cathode driven or grid driven service. > If you try to run it as true grounded grid you will MELT the grids! Mhmmm.. good info, Ken. Thank you !! -- 73's de IZ5FCY Roberto Article: 96841 of rec.radio.amateur.homebrew From: Roberto IZ5FCY Subject: Re: GG Tetrode/Pentode QRO References: <1afj8ab1gogi.qjys8f3ucsch$.dlg@40tude.net> Date: Tue, 14 Mar 2006 09:51:46 +0100 Message-ID: <1u3nud01x5cng$.1gio3y1vhc1ue.dlg@40tude.net> Excellent software mine, Reg !! Thanks and compliments. -- 73's de IZ5FCY Roberto Article: 96842 of rec.radio.amateur.homebrew From: Rex Subject: Re: What do you call these devices? Date: Tue, 14 Mar 2006 00:59:52 -0800 Message-ID: <451d12psikgo37pu10ko4ef7lumbk50g14@4ax.com> References: <1212j86qjoboec6@corp.supernews.com> On Fri, 10 Mar 2006 01:55:19 -0800, "Joel Kolstad" wrote: >At work we have these "do-hickeys" that look like a regular "tee" connector. >However, it's meant to be used such that a signal passes through the "top" >of the tee while the "leg" of the tee "picks off" the signal some 10dB or so >down from the input. (The insertion loss is some fraction of a dB.) The >pick off seems to just be a wire tip coming out of the backside of the >connector (just capacitively coupled?); there's an adjustable sleeve that >lets you position this tip closer or further from the through line; moving >it closer creates better coupling, but also tends to decrease frequency >flatness. The cool thing is that all ports drive 50 ohms, and the >pick-off's output is surprisingly flat over more than an octave. > >Any ideas? It's definitely not constructed the way I'd build a directional >coupler -- even though it performs a somewhat similar function --, nor a >"magic tee" (although I've only seem magic tees in the form of waveguides >and transformer-based affairs for HF). > >Thanks, >---Joel Kolstad > Here's a link to one manufacturer http://www.microlab.fxr.com/pdf/HX,HY,Hzseries.pdf As on their page, I've always called them samplers. The picture shows the probe end of an electromagnetic coupler with a wire loop to ground. The electrostatic version looks like the head of a nail sticking out of the teflon. Article: 96843 of rec.radio.amateur.homebrew From: Nedlar Subject: Re: Optical Communications? RSCB Irrelevance? (Was : Re: The smallest Baird Televisor?) Date: Tue, 14 Mar 2006 10:21:00 +0000 Message-ID: References: <66ia12hmnegvqp02shs20ganuqmp01an87@4ax.com> On Mon, 13 Mar 2006 23:17:38 +0000, Spike wrote: > >Nedlar wrote: > >>On Mon, 13 Mar 2006 11:54:53 +0000, Spike >>wrote: >> >>>That was very poor...is the medication wearing off? >>You're getting more childish by the hour. No wonder the kids hate you. >>( It's that word again, sorry it frightens you). >> >>Still not man enough to post the article eh? > >Still not man enough to repost one of your technical articles? > >I thought not. > >from >Aero Spike Still afraid to tell the truth? Article: 96844 of rec.radio.amateur.homebrew From: "Joel Kolstad" Subject: Re: What do you call these devices? Date: Tue, 14 Mar 2006 08:51:30 -0800 Message-ID: <121dt7d6b1mpha0@corp.supernews.com> References: <1212j86qjoboec6@corp.supernews.com> <451d12psikgo37pu10ko4ef7lumbk50g14@4ax.com> Hi Rex, "Rex" wrote in message news:451d12psikgo37pu10ko4ef7lumbk50g14@4ax.com... > Here's a link to one manufacturer > http://www.microlab.fxr.com/pdf/HX,HY,Hzseries.pdf Yep, that's them alright. The one we have is the electrostatic version. I took a closer look over a wider frequency range at its response and -- not too surprisingly -- it's a straight line on a log-log plot (i.e., the coupling is almost purely capacitive). Thanks for everyone's help, ---Joel Article: 96845 of rec.radio.amateur.homebrew From: "Mike Andrews" Subject: Re: What do you call these devices? Date: Tue, 14 Mar 2006 17:36:56 +0000 (UTC) Message-ID: References: <1212j86qjoboec6@corp.supernews.com> <451d12psikgo37pu10ko4ef7lumbk50g14@4ax.com> Rex wrote: > On Fri, 10 Mar 2006 01:55:19 -0800, "Joel Kolstad" > wrote: >>At work we have these "do-hickeys" that look like a regular "tee" connector. >>However, it's meant to be used such that a signal passes through the "top" >>of the tee while the "leg" of the tee "picks off" the signal some 10dB or so >>down from the input. (The insertion loss is some fraction of a dB.) The >>pick off seems to just be a wire tip coming out of the backside of the >>connector (just capacitively coupled?); there's an adjustable sleeve that >>lets you position this tip closer or further from the through line; moving >>it closer creates better coupling, but also tends to decrease frequency >>flatness. The cool thing is that all ports drive 50 ohms, and the >>pick-off's output is surprisingly flat over more than an octave. >> >>Any ideas? It's definitely not constructed the way I'd build a directional >>coupler -- even though it performs a somewhat similar function --, nor a >>"magic tee" (although I've only seem magic tees in the form of waveguides >>and transformer-based affairs for HF). > Here's a link to one manufacturer > http://www.microlab.fxr.com/pdf/HX,HY,Hzseries.pdf > As on their page, I've always called them samplers. > The picture shows the probe end of an electromagnetic coupler with a > wire loop to ground. The electrostatic version looks like the head of a > nail sticking out of the teflon. Yeah. for 50-12000 MHz. 6m and above and not much use for HF, then. Good thing they've got a feedback E-mail address, but I suspect that they'd want lots'o'$ for a one-off modification. -- "If God had intended us to vote, he'd have given us candidates." Article: 96846 of rec.radio.amateur.homebrew From: Spike Subject: Re: Optical Communications? RSCB Irrelevance? (Was : Re: The smallest Baird Televisor?) Date: Tue, 14 Mar 2006 17:42:00 +0000 Message-ID: <230e12p06p1jkja0ufqcj4n6tuktl1astn@4ax.com> References: <66ia12hmnegvqp02shs20ganuqmp01an87@4ax.com> Nedlar wrote: >On Mon, 13 Mar 2006 23:17:38 +0000, Spike >wrote: > >> >>Nedlar wrote: >> >>>On Mon, 13 Mar 2006 11:54:53 +0000, Spike >>>wrote: >>> >>>>That was very poor...is the medication wearing off? >>>You're getting more childish by the hour. No wonder the kids hate you. >>>( It's that word again, sorry it frightens you). >>> >>>Still not man enough to post the article eh? >> >>Still not man enough to repost one of your technical articles? >> >>I thought not. >> >>from >>Aero Spike > >Still afraid to tell the truth? Whatever are you blabbering on about? Truth? Would you know the meaning of the word? Truth about what? from Aero Spike Article: 96847 of rec.radio.amateur.homebrew From: "Joel Kolstad" Subject: Re: What do you call these devices? Date: Tue, 14 Mar 2006 10:16:03 -0800 Message-ID: <121e26cdhe9jscc@corp.supernews.com> References: <1212j86qjoboec6@corp.supernews.com> <451d12psikgo37pu10ko4ef7lumbk50g14@4ax.com> "Mike Andrews" wrote in message news:dv6uvo$o53$1@puck.litech.org... > Yeah. for 50-12000 MHz. 6m and above and not much use for HF, then. I suspect you could make your own for HF without too much difficulty by modifying something like a SO259 tee along with a standard PL259 connector. On the other hand, for HF you can make pretty decent directional couplers using transformers and get a significantly flatter response if you're looking to accurately measure signal levels. Article: 96848 of rec.radio.amateur.homebrew From: Bob Subject: Re: RF power transistor - CM10-12A datasheet, and stock References: <1142313821.705029.197960@i39g2000cwa.googlegroups.com> Message-ID: Date: Tue, 14 Mar 2006 18:54:09 GMT MarkAren wrote: > Hi Guys, > > Can anyone help with a full data sheet and an idea where I might be > able to buy one without getting charged the earth. > > Thanks, > > Mark. > I will only charge you the moon, not the earth.:-) It is 8 pages, which I will copy today and email to you. Enjoy. Bob, w6nbi -- When replying direct, remove the X from my address. Article: 96849 of rec.radio.amateur.homebrew From: Nedlar Subject: Re: Optical Communications? RSCB Irrelevance? (Was : Re: The smallest Baird Televisor?) Date: Tue, 14 Mar 2006 20:20:26 +0000 Message-ID: <0b9e12pe7m940l0m8hkua4h88cp4ht6qpg@4ax.com> References: <66ia12hmnegvqp02shs20ganuqmp01an87@4ax.com> <230e12p06p1jkja0ufqcj4n6tuktl1astn@4ax.com> On Tue, 14 Mar 2006 17:42:00 +0000, Spike wrote: > >Whatever are you blabbering on about? Truth? Would you know the >meaning of the word? Truth about what? > >from >Aero Spike Still digging eh? Tell the truth. HTH Article: 96850 of rec.radio.amateur.homebrew From: "Howard" Subject: Winding coils Message-ID: Date: Tue, 14 Mar 2006 20:45:37 GMT I can't find the answers to these in the books and I've wondered about them for years. When winding a coil on a standard (say 1/4") former with ferrite or iron dust core, should the secondary be wound adjacent to the "hot" end of the primary or the earthy end? Also, should the earthy end of the secondary be adjacent to the primary hot end or earthy end? What's the difference between dust iron and ferrite cores and can you tell the difference by just looking at them? Thanks. Howard. Article: 96851 of rec.radio.amateur.homebrew From: microwaves@blueyonder.co.uk (Peter) Subject: Re: Optical Communications? RSCB Irrelevance? (Was : Re: The smallest Baird Televisor?) Message-ID: <44173a9c.15307821@news.blueyonder.co.uk> References: <1142099027.152408.11300@i39g2000cwa.googlegroups.com> <1142146185.518102.243580@j52g2000cwj.googlegroups.com> Date: Tue, 14 Mar 2006 21:50:29 GMT On Sun, 12 Mar 2006 09:22:37 GMT, "Brian Reay" wrote: >> As these beasties come in a mounting that already >> has facilities for screw fixing, perhaps there is >> potential capability for optical communications? > >Been done. UK record, as of a couple of years back at least, was something >like 75km. There is project in the latest RSGB handbook (if you are >interesed I'll look up the page, I noticed the article but haven't read the >detail). The current UK laser record is around 73km I believe... held by G0MFR and G8LSD. They used standard low power red laser diodes of the kind found in the pointers. Barry,G8AGN, Gordon G0EWN and myself (all in Sheffield) are also experimenting on these lines have done a 45km path so far... using cw. We have some LOS paths up here in the North up to 136km so we're hoping to better the record one day soon :-) Peter, G3PHO Article: 96852 of rec.radio.amateur.homebrew From: "James F. Mayer" Subject: Digikey phishing Message-ID: Date: Tue, 14 Mar 2006 23:12:41 GMT Someone or a group of persons are phishing with the subject header "CC Pending Order Letter from Digi-Key for salesorder 16642643" I have received 2 (two) of them in the last two days and I have forwarded them to Digikey. They are investigating. If you receive any, please notify Digikey so thay can trsck down the culprits and prosecute them to the fullest extent of the law. Article: 96853 of rec.radio.amateur.homebrew From: ZS1KE Subject: Re: 4CX250B 2m linear circuit? (Class C ideally!) Date: Wed, 15 Mar 2006 07:04:58 -0000 Message-ID: References: Hi Samuel and all > > I'm trying to find a good circuit for a Class C 4CX250B linear. *cough* *cough* *choke* A Class C is *not* linear. I think the usage of "linear" for "an external amplifier to boost the power going to the antenna" comes from the CB crowd, who *do* need a linear amplifier (for SSB). OK, you want to boost FM, and for that you can use Class C. The only ARRL Handbook I have here (1992, I'm not counting the '48 :-) has two very similar schematics, one for a 3CX800 and the other for a 3CX1500, but I do seem to recall that a different edition had a 4CX250 schematic. Or maybe it's the RSGB handbook. > I've found a few for multiple valves in Class A, but I'm after just a > simple circuit that shows a 4CX250B linear for 2m with Class C > biasing. Don't search for "linear", search for "amplifier" :-) W Article: 96854 of rec.radio.amateur.homebrew From: "John A" Subject: Re: Wainwright Mini-Mounts Date: Wed, 15 Mar 2006 09:26:10 -0000 Message-ID: References: Thanks Leon and Per, WWM are linked to Wainwright filters, I suspect - but there is no sign of the Mini-Mount product or anything like it on Wainwright Filter's web-site. Thanks Phil, What we are looking for is TSSOP adapters (nt so easy to homebrew, Leon!), which rules out the items on Rapid's website. I'll keep looking, but many thanks for your thoughts - and any other still to come! John "John A" wrote in message news:dv0rmo$uoa$1@newsg2.svr.pol.co.uk... > Does anyone know of a UK source for "Wainwright Mini-mounts"? These are > small PCBs made in Germany by WMM GmbH (no web-site or email!), laid out to > take an IC, with tracks from each IC pad taken out to the edge of the PCB - > very useful for prototyping with TSSOP devices it seems. > > If they sound interesting, see: > > http://www.rdi-wainwright.com/ > > which is the site of the US agent - $100 min order! > > John > > > Article: 96855 of rec.radio.amateur.homebrew From: Spike Subject: Re: Optical Communications? RSCB Irrelevance? (Was : Re: The smallest Baird Televisor?) Date: Wed, 15 Mar 2006 09:46:26 +0000 Message-ID: References: <66ia12hmnegvqp02shs20ganuqmp01an87@4ax.com> <230e12p06p1jkja0ufqcj4n6tuktl1astn@4ax.com> <0b9e12pe7m940l0m8hkua4h88cp4ht6qpg@4ax.com> Nedlar wrote: >On Tue, 14 Mar 2006 17:42:00 +0000, Spike >wrote: > >>Whatever are you blabbering on about? Truth? Would you know the >>meaning of the word? Truth about what? >> > >Still digging eh? > >Tell the truth. Tell the truth or stop claiming a certain 'licence class'. >HTH from Aero Spike Article: 96856 of rec.radio.amateur.homebrew From: "Bill Turner" Subject: Re: focus group question for new products References: <1142406521.125109.71730@u72g2000cwu.googlegroups.com> Message-ID: <4418221f_5@newsfeed.slurp.net> Date: 15 Mar 2006 09:18:07 -0500 ORIGINAL MESSAGE: eternalsquire@comcast.net wrote: > Hi, > > If I could build a high quality rf-tight small enclosure for dc-30 Mhz > at low to moderate cost, what would you need? > > Thanks, > > The Eternal Squire *********** REPLY SEPARATOR *********** I use the Pomona die-cast boxes, but they are expensive. If you can improve the cost factor, I will beat a path to your doorstep, as will others. Bill, W6WRT Article: 96857 of rec.radio.amateur.homebrew From: "xpyttl" References: <1142406521.125109.71730@u72g2000cwu.googlegroups.com> Subject: Re: focus group question for new products Message-ID: Date: Wed, 15 Mar 2006 10:49:29 -0500 I find that boxes are generally too expensive, and rarely the right size. Generally, I want a box for the desk, so it typically could stand to be fairly deep -- say 7-10 inches. I also want it wide enough for a few controls and an LCD, so maybe again, 7-10 inches. The height generally seems to be the problem. It seems like boxes are either an inch and a half high, so you can't get a display in there, or 5 inches, way taller than necessary. I would think that 2.5-3" high boxes would be awfully handy, but they seem rare. And of course, they tend to be horribly expensive. Card guides inside would be nice. Aluminum would be nice so that it is easy to machine. Although in reality, some sort of lined plastic might be better. Thick enough to be strong, but thin enough that it doesn't weigh a ton -- plus, a thick panel looks junky in front of a display. Powder coated would be nice, but at least some reasonably clean finish so I don't have a ton of work to do before painting. I often use plastic boxes with a removeable, flat panel. I can replace the panel with plexiglas, so that instead of trying to make a square hole for the display, I can simply mask off a square hole. As an added bonus, my labels are protected by the plexi. Unfortunately, these kinds of boxes aren't RF tight. In an ideal world, I would have that sort of box, sprayed on the inside with RF proof paint, and with an insert I could place behind the display to make the front RF tight too, while still allowing for the display. Pipe dreams I guess. .. wrote in message news:1142406521.125109.71730@u72g2000cwu.googlegroups.com... > Hi, > > If I could build a high quality rf-tight small enclosure for dc-30 Mhz > at low to moderate cost, what would you need? > > Thanks, > > The Eternal Squire > Article: 96858 of rec.radio.amateur.homebrew From: "Juergen Kosel" Subject: 1 Million Visitors to your Website Message-ID: <_0XRf.1108$Yr.20@nntpserver.swip.net> Date: Wed, 15 Mar 2006 17:12:25 How To Get 1 Million Visitors On Your Web Site Without Paying A Dime In advertising ! Are you frustrated by the lack of traffic coming to your site? If I would tell you that after months of research, I just got my hands on the most hidden secrets... very sneaky tricks ! Click here : http://freeadguru.com/cgi-bin/i.pl?c=a&i=32460 Hurry, before the page gets banned! --- MAF Anti-Spam ID: 20060315091657M9n6YrV1 Article: 96859 of rec.radio.amateur.homebrew From: "johan aeq" References: <1142406521.125109.71730@u72g2000cwu.googlegroups.com> Subject: Re: focus group question for new products Date: Wed, 15 Mar 2006 18:40:18 +0100 Message-ID: <7367a$4418526b$52ad139c$2141@news.versatel.nl> i usually use unethed doublesided pcb and solder it together. "xpyttl" schreef in bericht news:hIWRf.13$vd5.0@fe06.lga... > I find that boxes are generally too expensive, and rarely the right size. > > Generally, I want a box for the desk, so it typically could stand to be > fairly deep -- say 7-10 inches. I also want it wide enough for a few > controls and an LCD, so maybe again, 7-10 inches. The height generally > seems to be the problem. It seems like boxes are either an inch and a half > high, so you can't get a display in there, or 5 inches, way taller than > necessary. I would think that 2.5-3" high boxes would be awfully handy, but > they seem rare. > > And of course, they tend to be horribly expensive. > > Card guides inside would be nice. > > Aluminum would be nice so that it is easy to machine. Although in reality, > some sort of lined plastic might be better. > > Thick enough to be strong, but thin enough that it doesn't weigh a ton -- > plus, a thick panel looks junky in front of a display. > > Powder coated would be nice, but at least some reasonably clean finish so I > don't have a ton of work to do before painting. > > I often use plastic boxes with a removeable, flat panel. I can replace the > panel with plexiglas, so that instead of trying to make a square hole for > the display, I can simply mask off a square hole. As an added bonus, my > labels are protected by the plexi. Unfortunately, these kinds of boxes > aren't RF tight. In an ideal world, I would have that sort of box, sprayed > on the inside with RF proof paint, and with an insert I could place behind > the display to make the front RF tight too, while still allowing for the > display. Pipe dreams I guess. > > .. > > wrote in message > news:1142406521.125109.71730@u72g2000cwu.googlegroups.com... > > Hi, > > > > If I could build a high quality rf-tight small enclosure for dc-30 Mhz > > at low to moderate cost, what would you need? > > > > Thanks, > > > > The Eternal Squire > > > > Article: 96860 of rec.radio.amateur.homebrew From: Allison-nospam@nouce.bellatlantic.net Subject: Re: focus group question for new products Message-ID: References: <1142406521.125109.71730@u72g2000cwu.googlegroups.com> Date: Wed, 15 Mar 2006 20:03:51 GMT On 14 Mar 2006 23:08:41 -0800, eternalsquire@comcast.net wrote: >Hi, > >If I could build a high quality rf-tight small enclosure for dc-30 Mhz >at low to moderate cost, what would you need? > >Thanks, > >The Eternal Squire I have plenty of diecast and Other aluminum boxes from various vendors. The usual problems are finding them and cos t(even aluminum miniboxes are costly for the metal sheet in them). Often a project will require several of differing sizes so I may make internal shield boxes box using single or two sided copper clad board (scrap). Cheap, solderable, good shielding. Whem I want something that looks good Hammond, LMB and TenTec offer very stylish boxes. Allison Article: 96861 of rec.radio.amateur.homebrew From: "kh" Message-ID: <0QMXZWh9EdSr-pn2-NH0e0dg7c19i@localhost> Subject: mini-DX-60 status report. Date: 16 Mar 2006 02:48:35 GMT -- Updated my mini-DX-60 page at www.kiyoinc.com/dx60.htm Please enjoy. de ah6gi/4 thinking about a mini-30S-1 now Article: 96862 of rec.radio.amateur.homebrew Subject: Crystal replacement From: "Joel" Date: Wed, 15 Mar 2006 23:31:20 -0600 Message-ID: <1142486941_139@sp6iad.superfeed.net> I have a couple 6 channel public service radios that are in the 155Mhz range. Some are synthesized and require cutting diodes to change the frequency and that works out well. But some are crystal controlled and with the cost and availability of crystals it's cost prohibitive to re-crystal these radios. It looks like these crystals are in the X9 mode so that puts them in the 16-16.5 MHz range. I am considering building a VCO to inject a signal into the old crystal socket to get around the crystal issue. Actually I figure a PIC to program the PLL would be great. I'm just not sure what frequency to inject into the old crystal socket. Should I build a 16mhz VCO or some harmonic? Will injecting a signal into a crystal-less oscillator even work? I'm going to use a ADF4110 PLL and a 16F89 PIC. Any suggestions for the VCO? Schematic for a 16 MHz VCO? Joe Loucka AG4QC ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- Article: 96864 of rec.radio.amateur.homebrew From: Allison-nospam@nouce.bellatlantic.net Subject: Re: Crystal replacement Message-ID: References: <1142486941_139@sp6iad.superfeed.net> Date: Thu, 16 Mar 2006 13:31:44 GMT On Wed, 15 Mar 2006 23:31:20 -0600, "Joel" wrote: >I have a couple 6 channel public service radios that are in the 155Mhz >range. Some are synthesized and require cutting diodes to change the >frequency and that works out well. >But some are crystal controlled and with the cost and availability of >crystals it's cost prohibitive to re-crystal these radios. It looks like >these crystals are in the X9 mode so that puts them in the 16-16.5 MHz >range. I am considering building a VCO to inject a signal into the old >crystal socket to get around the crystal issue. Actually I figure a PIC to >program the PLL would be great. I'm just not sure what frequency to inject >into the old crystal socket. Should I build a 16mhz VCO or some harmonic? >Will injecting a signal into a crystal-less oscillator even work? I'm going >to use a ADF4110 PLL and a 16F89 PIC. Any suggestions for the VCO? Schematic >for a 16 MHz VCO? > >Joe Loucka AG4QC If you going to do a "crystal equivilent" using a PIC and PLL the PLL system must be very well done to avoid the sideband noise that can occur when multiplied by 9 (or 18). The reason you need a PLL as a VCO has not the stability to hold a given frequency alone. An alternate is PIC + DDS chip. Getting crystals for older radios is not a lost cause, it's that they are not cheap and never were. Allison Article: 96865 of rec.radio.amateur.homebrew From: "John A" Subject: Re: Wainwright Mini-Mounts Date: Thu, 16 Mar 2006 15:15:17 -0000 Message-ID: References: <1142420039.036045.117250@e56g2000cwe.googlegroups.com> I'm impressed! I don't think that I could make PCBs to that sort of resolution and the prototype I made as a birdsnest five years ago, and which has recently expired, was built with eyesight that I can now only dream of. John "Leon" wrote in message news:1142420039.036045.117250@e56g2000cwe.googlegroups.com... > > I've homebrewed TSSOP (0.5 mm lead spacing) without problems. > > Leon > Article: 96866 of rec.radio.amateur.homebrew From: "Bob Spooner" Subject: Re: Question about 4-400 tube socket/mounting Date: Thu, 16 Mar 2006 10:53:41 -0500 Message-ID: References: <4412eccb_5@newsfeed.slurp.net> Why is the dissipation rating of the 4-400A lower when used in grounded grid service than it is when used in the traditional configuration? 73, Bob AD3K "Bill Turner" wrote in message news:4412eccb_5@newsfeed.slurp.net... > ORIGINAL MESSAGE: > > Straydog wrote: > >> there must be forced-air directed upwards from the non-tube side of >> the tube socket and there are specifications for flow rate and >> pressure. > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > "Flow rate and pressure" are nice, but the *only* important thing is > the temperature of the tube at various points as specified by the tube > manufacturer. If you are serious about proper tube cooling, use either > a non-contact thermometer of some kind or thermally-sensitive paint to > ensure your tube is within temp specs. Flow rate and pressure are a > means to an end, not an end in themselves. > > Bill, W6WRT Article: 96867 of rec.radio.amateur.homebrew From: "Samuel Hunt" Subject: FM S:N and C:N relationship? Date: Thu, 16 Mar 2006 18:09:24 +0000 (UTC) Message-ID: Does anyone know any sort of a formulas that might give me a clue as to the relationship between S:N and C:N for an FM system? I'm playing with narrow FM (500hz deviation kind of stuff), and want to try to work out the expected S:N for various different deviations with different C:N radios. Obviously the C:N improves with lower deviation because of the tighter IF filter, but the S:N will worsen because of the lower deviation, but I would appreciate some sort of help in the right direction for the formulas. Thanks all, Sam Article: 96868 of rec.radio.amateur.homebrew From: Allison-nospam@nouce.bellatlantic.net Subject: Re: Crystal replacement Message-ID: References: <1142486941_139@sp6iad.superfeed.net> <1142520347.864591.223820@e56g2000cwe.googlegroups.com> Date: Thu, 16 Mar 2006 19:33:17 GMT On 16 Mar 2006 06:45:47 -0800, "Tim Shoppa" wrote: >Allison-nospam@nouce.bellatlantic.net wrote: >> If you going to do a "crystal equivilent" using a PIC and PLL >> the PLL system must be very well done to avoid the sideband noise >> that can occur when multiplied by 9 (or 18). The reason you need a >> PLL as a VCO has not the stability to hold a given frequency alone. > >It depends on mode, reference frequency, et al. VHF-FM and VHF-AM are >remarkably less sensitive to crap coming out of the synthesizer than >say HF SSB operation. I shiver when I look at the 50's and 60's ARRL >handbooks and see construction articles for 2M and 70cm transmitters >using a tube VFO at 8MHz multiplied all the way up! ;) Yes I remember when. T44 strip anyone? > >All that said, chips made specifically for VHF synth operation >(MC145170) are available as are kits using these marketed towards hams >(e.g. http://www.dckits.com/ ) who want to play around and learn. It's >not a guarantee that you won't be radiating crap all over the public >service frequencies of course (that is the biggest risk here, isn't >it?) > >Tim. The real problem is older radio use 8 or 16 mhz with *8 or *18 multiplier. That means for 15khz channels your reference is 1.66667khz or 833.333hz respectively , and filtering the low reference has always been tougher. Most PLLs for VHF and up are direct with 2.5khz or higher reference and output directly in band or maybe a small offset (10.7mhz if or the like) so it's easier to keep the reference out of the audio. The cheap way out is a VHF PLL and then divide the output down to 16mhz. No mater what it's more complex than just a crystal. There is also the problem of some radios direct FM the crystal with a varicap diode. A stable source will not be FM'd that way. If one is lucky and the radio uses a reactance (phasing) mod then it will work. Allison KB!GMX Old radio and old computers plus new tech. Article: 96869 of rec.radio.amateur.homebrew Date: Fri, 17 Mar 2006 01:38:56 +0200 From: Risto Tiilikainen Subject: Re: Winding coils References: Message-ID: <4419f609$0$7480$39db0f71@news.song.fi> Tim Wescott kirjoitti: > > > Ferrite cores usually have higher permitivity, which means more > inductance for the same number of winds. They also usually saturate > quicker, which means that they aren't as good for resonant circuits or > for filters. > Hi The great advantage of ferrite materials is just what you said - more inductance for the same number of winds. In this way high Q coils can be done. A good example is direction finding receiver with ferrite rod antenna for magnetical field component of fox transmitter. I agree that saturation can be a problem in higher power levells Anyhow good high power baluns are made with toroids and filament chokes with ferrite rods for grounded grid linears ( Yes- they are not tuned resonant circuits ) 73, Risto OH2BT Article: 96871 of rec.radio.amateur.homebrew Date: Fri, 17 Mar 2006 14:49:53 +0800 From: Richard Hosking Subject: Re: Crystal replacement References: <1142486941_139@sp6iad.superfeed.net> Message-ID: <441a5c11$0$18561$5a62ac22@per-qv1-newsreader-01.iinet.net.au> If its for commercial use it would probably be easiest just to get the crystals. Otherwise designing a PLL system is possible - particularly if you want to learn about them for your own education. But the work involved is not trivial - probably not worth it for a few old radios. The other issue will be how the radio achieves FM - if it does it swinging the crystal, then this will impose another restriction on the PLL. While it is possible to do (keep loop filter BW below min audio freq) I tried doing this on a 2M design once - couldnt get it stable. Some radios phase modulate one of the multipliers, which would avoid this issue. R Joel wrote: > I have a couple 6 channel public service radios that are in the 155Mhz > range. Some are synthesized and require cutting diodes to change the > frequency and that works out well. > But some are crystal controlled and with the cost and availability of > crystals it's cost prohibitive to re-crystal these radios. It looks like > these crystals are in the X9 mode so that puts them in the 16-16.5 MHz > range. I am considering building a VCO to inject a signal into the old > crystal socket to get around the crystal issue. Actually I figure a PIC to > program the PLL would be great. I'm just not sure what frequency to inject > into the old crystal socket. Should I build a 16mhz VCO or some harmonic? > Will injecting a signal into a crystal-less oscillator even work? I'm going > to use a ADF4110 PLL and a 16F89 PIC. Any suggestions for the VCO? Schematic > for a 16 MHz VCO? > > Joe Loucka AG4QC > > > > ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- > http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups > ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- Article: 96872 of rec.radio.amateur.homebrew Subject: Re: Crystal replacement From: "Joel" Date: Fri, 17 Mar 2006 01:01:23 -0600 Message-ID: <1142578756_9403@sp6iad.superfeed.net> References: <1142486941_139@sp6iad.superfeed.net> <441a5c11$0$18561$5a62ac22@per-qv1-newsreader-01.iinet.net.au> The idea is we have a few dozen crystallized Maxon 4010's here and figured we could get them converted to 2 meters to give to the new ham's in the area. We would do the crystal route, but crystals seem to be in the $12.50 or more range (If you can even find them) That means it would be about 25 buck/channel. The price quickly makes conversion cost prohibitive compared to a new 2 meter radio. I reversed engineered the Maxon 3010 as they are synthesized and by cutting diodes we have them working on 2 meters. Of course, having a schematic for either radio would make things a lot easer.. (hint).. Joe Loucka AG4QC "Richard Hosking" wrote in message news:441a5c11$0$18561$5a62ac22@per-qv1-newsreader-01.iinet.net.au... > If its for commercial use it would probably be easiest just to get the > crystals. > Otherwise designing a PLL system is possible - particularly if you want to > learn about them for your own education. But the work involved is not > trivial - probably not worth it for a few old radios. The other issue will > be how the radio achieves FM - if it does it swinging the crystal, then > this will impose another restriction on the PLL. While it is possible to > do (keep loop filter BW below min audio freq) I tried doing this on a 2M > design once - couldnt get it stable. Some radios phase modulate one of the > multipliers, which would avoid this issue. > > R > > Joel wrote: >> I have a couple 6 channel public service radios that are in the 155Mhz >> range. Some are synthesized and require cutting diodes to change the >> frequency and that works out well. >> But some are crystal controlled and with the cost and availability of >> crystals it's cost prohibitive to re-crystal these radios. It looks like >> these crystals are in the X9 mode so that puts them in the 16-16.5 MHz >> range. I am considering building a VCO to inject a signal into the old >> crystal socket to get around the crystal issue. Actually I figure a PIC >> to program the PLL would be great. I'm just not sure what frequency to >> inject into the old crystal socket. Should I build a 16mhz VCO or some >> harmonic? Will injecting a signal into a crystal-less oscillator even >> work? I'm going to use a ADF4110 PLL and a 16F89 PIC. Any suggestions >> for the VCO? Schematic for a 16 MHz VCO? >> >> Joe Loucka AG4QC ----== Posted via Newsfeeds.Com - >> Unlimited-Unrestricted-Secure Usenet News==---- >> http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ >> Newsgroups >> ----= East and West-Coast Server Farms - Total Privacy via Encryption >> =---- > ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- Article: 96873 of rec.radio.amateur.homebrew Subject: Re: Crystal replacement From: "Joel" Date: Fri, 17 Mar 2006 09:03:17 -0600 Message-ID: <1142607665_9759@sp6iad.superfeed.net> References: <1142486941_139@sp6iad.superfeed.net> <441a5c11$0$18561$5a62ac22@per-qv1-newsreader-01.iinet.net.au> <1142578756_9403@sp6iad.superfeed.net> Scott, I hear your point.. These are not HT's but 40 watt mobiles. I understand how cheap HT's are and that's why I can't see spending much resources on the conversion. But I'm always looking for new uses to implement PIC chips and interfacing one to a synthesizer seemed like an inexpensive idea. PIC and synthesizer cost together is barely 12 bucks. Joe Loucka AG4QC "Scott" wrote in message news:jJ-dncrEDuwYN4fZnZ2dnUVZ_vmdnZ2d@bright.net... > Here's another idea...instead of making these radios to hand out to new > hams, maybe you could remove the transmit crystal and just replace the > receive crystal, lowering the conversion cost. You could hand these out > to NON-HAMS so they could listen in on the local repeater or simplex > channel. Maybe they would be interested in becoming hams. 2M HTs are so > cheap these days, just about any new ham can afford one with a lot of > bells and whistles built in. > > Scott > N0EDV > > Joel wrote: >> The idea is we have a few dozen crystallized Maxon 4010's here and >> figured we could get them converted to 2 meters to give to the new ham's >> in the area. We would do the crystal route, but crystals seem to be in >> the $12.50 or more range (If you can even find them) That means it would >> be about 25 buck/channel. The price quickly makes conversion cost >> prohibitive compared to a new 2 meter radio. >> >> I reversed engineered the Maxon 3010 as they are synthesized and by >> cutting diodes we have them working on 2 meters. Of course, having a >> schematic for either radio would make things a lot easer.. (hint).. >> >> Joe Loucka AG4QC >> >> >> >> "Richard Hosking" wrote in message >> news:441a5c11$0$18561$5a62ac22@per-qv1-newsreader-01.iinet.net.au... >> >>>If its for commercial use it would probably be easiest just to get the >>>crystals. >>>Otherwise designing a PLL system is possible - particularly if you want >>>to learn about them for your own education. But the work involved is not >>>trivial - probably not worth it for a few old radios. The other issue >>>will be how the radio achieves FM - if it does it swinging the crystal, >>>then this will impose another restriction on the PLL. While it is >>>possible to do (keep loop filter BW below min audio freq) I tried doing >>>this on a 2M design once - couldnt get it stable. Some radios phase >>>modulate one of the multipliers, which would avoid this issue. >>> >>>R >>> >>>Joel wrote: >>> >>>>I have a couple 6 channel public service radios that are in the 155Mhz >>>>range. Some are synthesized and require cutting diodes to change the >>>>frequency and that works out well. >>>>But some are crystal controlled and with the cost and availability of >>>>crystals it's cost prohibitive to re-crystal these radios. It looks like >>>>these crystals are in the X9 mode so that puts them in the 16-16.5 MHz >>>>range. I am considering building a VCO to inject a signal into the old >>>>crystal socket to get around the crystal issue. Actually I figure a PIC >>>>to program the PLL would be great. I'm just not sure what frequency to >>>>inject into the old crystal socket. Should I build a 16mhz VCO or some >>>>harmonic? Will injecting a signal into a crystal-less oscillator even >>>>work? I'm going to use a ADF4110 PLL and a 16F89 PIC. Any suggestions >>>>for the VCO? Schematic for a 16 MHz VCO? >>>> >>>>Joe Loucka AG4QC ----== Posted via Newsfeeds.Com - >>>>Unlimited-Unrestricted-Secure Usenet News==---- >>>>http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ >>>>Newsgroups >>>>----= East and West-Coast Server Farms - Total Privacy via Encryption >>>>=---- >>> >> >> >> >> ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet >> News==---- >> http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ >> Newsgroups >> ----= East and West-Coast Server Farms - Total Privacy via Encryption >> =---- > ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- Article: 96874 of rec.radio.amateur.homebrew From: "Steve Nosko" Subject: Re: What do you call these devices? Date: Fri, 17 Mar 2006 11:51:12 -0600 Message-ID: References: <1212j86qjoboec6@corp.supernews.com> <451d12psikgo37pu10ko4ef7lumbk50g14@4ax.com> <121dt7d6b1mpha0@corp.supernews.com> "Joel Kolstad" wrote in message news:121dt7d6b1mpha0@corp.supernews.com... > Hi Rex, > > "Rex" wrote in message > news:451d12psikgo37pu10ko4ef7lumbk50g14@4ax.com... > > Here's a link to one manufacturer > > http://www.microlab.fxr.com/pdf/HX,HY,Hzseries.pdf > > Yep, that's them alright. The one we have is the electrostatic version. > > I took a closer look over a wider frequency range at its response and -- not > too surprisingly -- it's a straight line on a log-log plot (i.e., the coupling > is almost purely capacitive). > > Thanks for everyone's help, > ---Joel > > I don't know what Butches point was.... I think I was close, no? Don't they have a number and name stamped on them? Usually uLab does that. Google is mighty powerful in this regard. 73, Steve, K9DCI Article: 96875 of rec.radio.amateur.homebrew From: microwaves@blueyonder.co.uk (Peter) Subject: Re: Optical Communications? RSCB Irrelevance? (Was : Re: The smallest Baird Televisor?) Message-ID: <441b25d8.272135830@news.blueyonder.co.uk> References: <1142099027.152408.11300@i39g2000cwa.googlegroups.com> <1142146185.518102.243580@j52g2000cwj.googlegroups.com> <44173a9c.15307821@news.blueyonder.co.uk> Date: Fri, 17 Mar 2006 21:12:11 GMT On Tue, 14 Mar 2006 21:50:29 GMT, microwaves@blueyonder.co.uk (Peter) wrote: >The current UK laser record is around 73km I believe... held by G0MFR >and G8LSD. Whooops! G0MFR should read G0MRF ... sorry Dave! peter, G3PHO Article: 96876 of rec.radio.amateur.homebrew From: "James Thompson" References: <1142486941_139@sp6iad.superfeed.net> <441a5c11$0$18561$5a62ac22@per-qv1-newsreader-01.iinet.net.au> <1142578756_9403@sp6iad.superfeed.net> Subject: Re: Crystal replacement Date: Fri, 17 Mar 2006 17:05:18 -0500 Message-ID: > area. We would do the crystal route, but crystals seem to be in the $12.50 > or more range (If you can even find them) That means it would be about 25 > buck/channel. The price quickly makes conversion cost prohibitive compared > to a new 2 meter radio. What crystal do you need? Digikey sells most crystals for .60 to 1.50 each , where did you look to find them costing 12 bucks each? curious.... Jim Article: 96877 of rec.radio.amateur.homebrew From: TW Subject: Data needed on RF2065 MMIC - similar to MAR-3 Message-ID: Date: Fri, 17 Mar 2006 18:48:51 -0500 I need a datasheet on the RF2065 MMIC, or more specifically, RF2065TR7M. Supposed to be similar to the MAR-3, but I can't prove it. The guy I bought some from tested it as if it were a MAR-3, he says. I want to use it in the circuit of Fig. 11.14 of EMRFD (U4). Note that the part type designations for the MMICs in that figure are inconsistent with the block diagram of Fig 11.13...U4 should be a MAR-3 or MSA-0385 (I guess), not an MSA-0685 Yes, I've Goggled to the max, did all of the datasheetcatalog.com-type and we-may-have-it-but-you-to-buy-the-info.com-type places, and called and wrote RF Microdevices sales support. No joy. This device must have been either been developed specifically for a US Gov't Tippy-Top Secret, Burn Before Reading project, or was the subject of a massive recall; both pure speculation on my part. Tnx, Article: 96878 of rec.radio.amateur.homebrew From: Allison-nospam@nouce.bellatlantic.net Subject: Re: Crystal replacement Message-ID: <9tvm125jc83tb3kgukigsmoqtgo1fd8cgo@4ax.com> References: <1142486941_139@sp6iad.superfeed.net> <441a5c11$0$18561$5a62ac22@per-qv1-newsreader-01.iinet.net.au> <1142578756_9403@sp6iad.superfeed.net> Date: Sat, 18 Mar 2006 03:43:04 GMT On Fri, 17 Mar 2006 17:05:18 -0500, "James Thompson" wrote: >> area. We would do the crystal route, but crystals seem to be in the $12.50 >> or more range (If you can even find them) That means it would be about 25 >> buck/channel. The price quickly makes conversion cost prohibitive compared >> to a new 2 meter radio. >What crystal do you need? Digikey sells most crystals for .60 to 1.50 each >, where did you look to find them costing 12 bucks each? curious.... Jim > Those are standard frequencies used for modems and microprocessors and are cheap because of common frequencies and bulk production. Most are low tolerence or not temperature stable. Not to say they are junk just not designed for the same use. For radios (old VHF crystal controlled ones) the crystals are typically x*16 (or x*18) for TX and X*3+IF for RX and must be accurate to .001% to be useful. So a set for an old radio I have would be for the 146.34/94 pair (9.14625mhz TX and 45.146667mhz RX). This requires crystals ground to spec (custom) and 25$ a pair is actually pretty good. There are a few companies that do this. Allison Article: 96879 of rec.radio.amateur.homebrew From: Allison-nospam@nouce.bellatlantic.net Subject: Re: Data needed on RF2065 MMIC - similar to MAR-3 Message-ID: References: Date: Sat, 18 Mar 2006 03:58:30 GMT On Fri, 17 Mar 2006 18:48:51 -0500, TW wrote: >I need a datasheet on the RF2065 MMIC, or more specifically, >RF2065TR7M. Supposed to be similar to the MAR-3, but I can't prove >it. The guy I bought some from tested it as if it were a MAR-3, he >says. > >I want to use it in the circuit of Fig. 11.14 of EMRFD (U4). Note >that the part type designations for the MMICs in that figure are >inconsistent with the block diagram of Fig 11.13...U4 should be a >MAR-3 or MSA-0385 (I guess), not an MSA-0685 For that application at 18mhz there is plenty of room for subs. The mar3 or something reasonably close will be fine. You only need enough gain to set the noise figure byb offsetting the losses in the DBMs and image stripping filters. >Yes, I've Goggled to the max, did all of the datasheetcatalog.com-type >and we-may-have-it-but-you-to-buy-the-info.com-type places, and called >and wrote RF Microdevices sales support. No joy. This device must >have been either been developed specifically for a US Gov't Tippy-Top >Secret, Burn Before Reading project, or was the subject of a massive >recall; both pure speculation on my part. > >Tnx, Or it's so old everyone forgot they made it! Really, it does happen!!! For circuits in EMRFD using MIMICs all you need to substitue them is: Gain Max power out Noise figure Then order the nearest MAR or ERA part from Minicircuits. Or as I've done in many cases is use a 2n3904 (2n5109 if more bandwidth is needed) in a broadband 50ohm amp circuit (from earlier in the book). Same performance and I can build from my parts bin and tweek it for my usage. I save the mmics for where space or frequencies greater than 100mhz are important to me. Most cases the lattitue is fairly wide and the specific circuit details will call out the needed info to apply it. Allison Article: 96880 of rec.radio.amateur.homebrew From: "noexqs" Subject: Re: Solid state vhf and UHF amplifier designs? Date: Sat, 18 Mar 2006 14:48:33 +0100 Message-ID: <121o3tjb17lkt25@corp.supernews.com> References: Mike, have a look at: http://www.qsl.net/yu1aw/VHFPower.htm A simple design with MRF317 (28V): http://hjem.get2net.dk/ole_nykjaer/oz2oe/mrf317/317.html You may find some of the transistors used to be obsolete regards, Willem PE2WDO Holland "VK3XL" schreef in bericht news:VK3XL.24nka8@news.radiobanter.com... > > Hi all, Im looking for solid state amplifier designs for use on 144 MHZ > SSB of about 100 W output for up to 20 watts drive. Does anyone have > links to suitable circuit diagrams? > I am also interested to increase my output power on 432 SSB as well. I > currently have 10 w drive and would like to increase that to 100w or > there abouts. Solid state amp circuits only please > Thanks for looking > Mike VK3XL > > > -- > VK3XL Article: 96881 of rec.radio.amateur.homebrew From: Allison-nospam@nouce.bellatlantic.net Subject: Re: Return Loss Bridge Accuracy Questions Message-ID: References: <1142687392.568430.122110@e56g2000cwe.googlegroups.com> Date: Sat, 18 Mar 2006 16:13:41 GMT On 18 Mar 2006 05:09:52 -0800, skavanagh72nospam@yahoo.ca wrote: >I have just built an HF return loss bridge according to the info in >"Solid State design for the Radio Amateur". While it works ok, I was >hoping for a bit better performance. Clearly the "balun" doesn't have >enough inductance to operate well below 10 MHz or so (10 turns bifilar >#30 AWG enamelled wire on Amidon T23-43, as specified in the book - >twisted pair, which isn't specified one way or the other in the book). > This can probably be largely fixed by using a larger ferrite core >(T37-43's available in junkbox). I am interested primarily in the >1.8-50 MHz range, though I wouldn't complain if it worked on 2m too. > >But even at 30 MHz a reasonably good microwave 50 ohm load gives only >about 28 dB apparent return loss...Not bad, but I might have expected a >bit more. > >And an open and short give about 2 dB different signal levels at 30 >MHz. That is with big pads (>20 dB attenuation) on both the signal >generator and detector. The detector is an HF receiver with a step >attenuator used to maintain a constant S-meter reading. > >The circuit is built on a small PC board using construction techniques >typical for the UHF or low microwave range (except that the test port >connector is an SO-239), and is enclosed in a shielded box. Each of >the three 50 ohm resistors is made of two 100 ohm 1206 chip resistors >in parallel and measures between 50.0 and 50.3 ohms at DC. > >Has anyone with experience with this circuit any suggestions for how to >tweak it for best performance ? What accuracy level have you achieved >? Do you know where I might find an error analysis for this circuit ? >Or if I am to think about errors myself, does anyone know how to model >the balun in SPICE ? > >73, >Steve VE3SMA My first guess is leakage around the test fixture. Incidental radiation and coupling around the bridge can be a source of errors. the test for that is to use a well shielded RF source and minimal RF and run the tests with less detector (RX) gain. For a lot of tests getting better than 20db return loss is adaquate accuracy. Allison Article: 96882 of rec.radio.amateur.homebrew From: Unknown Subject: Re: Interested? Here's your FAQ! Message-ID: References: <1142667554.414942.269330@g10g2000cwb.googlegroups.com> Date: Sat, 18 Mar 2006 18:39:45 GMT Just fuck off and get a life ...... please ....... Article: 96883 of rec.radio.amateur.homebrew From: "CA" References: <1142687392.568430.122110@e56g2000cwe.googlegroups.com> Subject: Re: Return Loss Bridge Accuracy Questions Message-ID: Date: Sat, 18 Mar 2006 19:28:15 GMT My homebrew RLB uses a current balun. Some turns of thin 50 Ohm coax on a ferrite core. The core is from a scrapped Siemens inductor. I have acheived good performance between 0,1 to 200 MHz with this technique. I first tried the twisted pair winding approach but the current balun was far better. Chris SM6PXJ skavanagh72nospam@yahoo.ca wrote: > I have just built an HF return loss bridge according to the info in > "Solid State design for the Radio Amateur". While it works ok, I was > hoping for a bit better performance. Clearly the "balun" doesn't have > enough inductance to operate well below 10 MHz or so (10 turns bifilar > #30 AWG enamelled wire on Amidon T23-43, as specified in the book - > twisted pair, which isn't specified one way or the other in the > book). This can probably be largely fixed by using a larger ferrite > core (T37-43's available in junkbox). I am interested primarily in > the > 1.8-50 MHz range, though I wouldn't complain if it worked on 2m too. > > But even at 30 MHz a reasonably good microwave 50 ohm load gives only > about 28 dB apparent return loss...Not bad, but I might have expected > a bit more. > > And an open and short give about 2 dB different signal levels at 30 > MHz. That is with big pads (>20 dB attenuation) on both the signal > generator and detector. The detector is an HF receiver with a step > attenuator used to maintain a constant S-meter reading. > > The circuit is built on a small PC board using construction techniques > typical for the UHF or low microwave range (except that the test port > connector is an SO-239), and is enclosed in a shielded box. Each of > the three 50 ohm resistors is made of two 100 ohm 1206 chip resistors > in parallel and measures between 50.0 and 50.3 ohms at DC. > > Has anyone with experience with this circuit any suggestions for how > to tweak it for best performance ? What accuracy level have you > achieved ? Do you know where I might find an error analysis for this > circuit ? Or if I am to think about errors myself, does anyone know > how to model the balun in SPICE ? > > 73, > Steve VE3SMA Article: 96884 of rec.radio.amateur.homebrew From: Bob Subject: Re: Return Loss Bridge Accuracy Questions References: <1142687392.568430.122110@e56g2000cwe.googlegroups.com> Message-ID: <7KZSf.45026$2O6.20183@newssvr12.news.prodigy.com> Date: Sat, 18 Mar 2006 20:05:23 GMT skavanagh72nospam@yahoo.ca wrote: > I have just built an HF return loss bridge according to the info in > "Solid State design for the Radio Amateur". While it works ok, I was > hoping for a bit better performance. Clearly the "balun" doesn't have > enough inductance to operate well below 10 MHz or so (10 turns bifilar > #30 AWG enamelled wire on Amidon T23-43, as specified in the book - > twisted pair, which isn't specified one way or the other in the book). > This can probably be largely fixed by using a larger ferrite core > (T37-43's available in junkbox). I am interested primarily in the > 1.8-50 MHz range, though I wouldn't complain if it worked on 2m too. > > But even at 30 MHz a reasonably good microwave 50 ohm load gives only > about 28 dB apparent return loss...Not bad, but I might have expected a > bit more. > > And an open and short give about 2 dB different signal levels at 30 > MHz. That is with big pads (>20 dB attenuation) on both the signal > generator and detector. The detector is an HF receiver with a step > attenuator used to maintain a constant S-meter reading. > > The circuit is built on a small PC board using construction techniques > typical for the UHF or low microwave range (except that the test port > connector is an SO-239), and is enclosed in a shielded box. Each of > the three 50 ohm resistors is made of two 100 ohm 1206 chip resistors > in parallel and measures between 50.0 and 50.3 ohms at DC. > > Has anyone with experience with this circuit any suggestions for how to > tweak it for best performance ? What accuracy level have you achieved > ? Do you know where I might find an error analysis for this circuit ? > Or if I am to think about errors myself, does anyone know how to model > the balun in SPICE ? > > 73, > Steve VE3SMA > Directivity plays a large part in the accuracy of return-loss measurements. Do some research on how to determine the directivity of the bridge. If the directivity is less than 30 dB, the return-loss accuracy will be impacted substantially. Bob, w6nbi -- When replying direct, remove the X from my address. Article: 96885 of rec.radio.amateur.homebrew Subject: Re: Crystal replacement From: "Joel" Date: Sat, 18 Mar 2006 15:09:49 -0600 Message-ID: <1142716054_11637@sp6iad.superfeed.net> References: <1142486941_139@sp6iad.superfeed.net> <441a5c11$0$18561$5a62ac22@per-qv1-newsreader-01.iinet.net.au> <1142578756_9403@sp6iad.superfeed.net> <1142607665_9759@sp6iad.superfeed.net> Interestingly, that's exactly what I did.. I revered engineered the Maxon 3010 and have them working fine. Take a look at http://www.w4fhu.org/maxon-3010.htm The Maxon 4010 looks the same from the outside and it appears they started using them because they were probably cheaper. But the 4010's are crystal controlled and that's where I began. Yup, I DO plan on using a PIC and PLL or DDS. Actually the 3010's have the same chip you referenced at Jamco (As you can see from my webpage, above).. I was hoping to use a more modern chip but they all seem to be in the TTSOP format. Actually, I would love to use the AD9835 DDS but again, it's in this TTSOP format and not conductive to homebrewing. Sure I can solder the chip to a ckt board, but I'm not about to have a cktboard made up for a few copies and then find out I made a mistake because I can't really try it before hand. Sort of a catch-22. I am now starting to think about creating a pc board for just the chip to be able to bring out the leads to make them more available for breadboarding. I like the idea of them being in small packages as it cuts down on stray inductances and so on, so sure I'll use them once I have a proven ckt. Ah, lets see what else I can whine about.. LOL Joe Loucka AG4QC "Scott" wrote in message news:qISdnaA6CuNbbobZRVn-qQ@bright.net... > Oh, oops...didn't realize they were a mobile rig! I would think you might > be able to find a suitable schematic for the PLL circuitry by looking at > the data sheets for some of the PLL ICs...such as... > > http://www.jameco.com/wcsstore/Jameco/Products/ProdDS/246713MOT.pdf > > Have you investigated using a DDS (Direct Digital Synthesizer) with a PIC > to control it? > > Scott > > > Joel wrote: > >> Scott, >> I hear your point.. These are not HT's but 40 watt mobiles. I understand >> how cheap HT's are and that's why I can't see spending much resources on >> the conversion. But I'm always looking for new uses to implement PIC >> chips and interfacing one to a synthesizer seemed like an inexpensive >> idea. PIC and synthesizer cost together is barely 12 bucks. >> >> Joe Loucka AG4QC >> >> "Scott" wrote in message >> news:jJ-dncrEDuwYN4fZnZ2dnUVZ_vmdnZ2d@bright.net... >> >>>Here's another idea...instead of making these radios to hand out to new >>>hams, maybe you could remove the transmit crystal and just replace the >>>receive crystal, lowering the conversion cost. You could hand these out >>>to NON-HAMS so they could listen in on the local repeater or simplex >>>channel. Maybe they would be interested in becoming hams. 2M HTs are so >>>cheap these days, just about any new ham can afford one with a lot of >>>bells and whistles built in. >>> >>>Scott >>>N0EDV >>> >>>Joel wrote: >>> >>>>The idea is we have a few dozen crystallized Maxon 4010's here and >>>>figured we could get them converted to 2 meters to give to the new ham's >>>>in the area. We would do the crystal route, but crystals seem to be in >>>>the $12.50 or more range (If you can even find them) That means it would >>>>be about 25 buck/channel. The price quickly makes conversion cost >>>>prohibitive compared to a new 2 meter radio. >>>> >>>> I reversed engineered the Maxon 3010 as they are synthesized and by >>>> cutting diodes we have them working on 2 meters. Of course, having a >>>> schematic for either radio would make things a lot easer.. (hint).. >>>> >>>>Joe Loucka AG4QC >>>> >>>> >>>> >>>>"Richard Hosking" wrote in message >>>>news:441a5c11$0$18561$5a62ac22@per-qv1-newsreader-01.iinet.net.au... >>>> >>>> >>>>>If its for commercial use it would probably be easiest just to get the >>>>>crystals. >>>>>Otherwise designing a PLL system is possible - particularly if you want >>>>>to learn about them for your own education. But the work involved is >>>>>not trivial - probably not worth it for a few old radios. The other >>>>>issue will be how the radio achieves FM - if it does it swinging the >>>>>crystal, then this will impose another restriction on the PLL. While it >>>>>is possible to do (keep loop filter BW below min audio freq) I tried >>>>>doing this on a 2M design once - couldnt get it stable. Some radios >>>>>phase modulate one of the multipliers, which would avoid this issue. >>>>> >>>>>R >>>>> >>>>>Joel wrote: >>>>> >>>>> >>>>>>I have a couple 6 channel public service radios that are in the 155Mhz >>>>>>range. Some are synthesized and require cutting diodes to change the >>>>>>frequency and that works out well. >>>>>>But some are crystal controlled and with the cost and availability of >>>>>>crystals it's cost prohibitive to re-crystal these radios. It looks >>>>>>like these crystals are in the X9 mode so that puts them in the >>>>>>16-16.5 MHz range. I am considering building a VCO to inject a signal >>>>>>into the old crystal socket to get around the crystal issue. Actually >>>>>>I figure a PIC to program the PLL would be great. I'm just not sure >>>>>>what frequency to inject into the old crystal socket. Should I build a >>>>>>16mhz VCO or some harmonic? Will injecting a signal into a >>>>>>crystal-less oscillator even work? I'm going to use a ADF4110 PLL and >>>>>>a 16F89 PIC. Any suggestions for the VCO? Schematic for a 16 MHz VCO? >>>>>> >>>>>>Joe Loucka AG4QC ----== Posted via Newsfeeds.Com - >>>>>>Unlimited-Unrestricted-Secure Usenet News==---- >>>>>>http://www.newsfeeds.com The #1 Newsgroup Service in the World! >>>>>>120,000+ Newsgroups >>>>>>----= East and West-Coast Server Farms - Total Privacy via Encryption >>>>>>=---- >>>>> >>>> >>>> >>>>----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet >>>>News==---- >>>>http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ >>>>Newsgroups >>>>----= East and West-Coast Server Farms - Total Privacy via Encryption >>>>=---- >>> >> >> >> >> ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet >> News==---- >> http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ >> Newsgroups >> ----= East and West-Coast Server Farms - Total Privacy via Encryption >> =---- > ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- Article: 96886 of rec.radio.amateur.homebrew Subject: Any receiver IC's? From: JJ Message-ID: <4db24$441c7a6d$d135c4af$17969@MDI.CA> Date: Sat, 18 Mar 2006 16:23:57 -0500 What are some modern IC's to build a sensitive and strong HAM receiver? Mixers and IF amps recommended? Not looking for NE602 but higher performance. JJ Article: 96887 of rec.radio.amateur.homebrew Subject: Re: Any receiver IC's? From: JJ References: <4db24$441c7a6d$d135c4af$17969@MDI.CA> <1142720911.911739.64900@g10g2000cwb.googlegroups.com> Message-ID: <1cc48$441c9894$d135c4af$31146@MDI.CA> Date: Sat, 18 Mar 2006 18:32:36 -0500 "Leon" wrote in news:1142720911.911739.64900@ > > Bus switches like the FST3125 make very good mixers and quadrature > sampling detectors, as in the SoftRock SDRs. > > Leon > > And how about the IF amp? And VFO? DDS like AD9850 look interesting. JJ Article: 96888 of rec.radio.amateur.homebrew From: Chris Jones Subject: Re: Return Loss Bridge Accuracy Questions Date: Sat, 18 Mar 2006 23:48:33 +0000 Message-ID: <121p71ulqb3i8b3@corp.supernews.com> References: <1142687392.568430.122110@e56g2000cwe.googlegroups.com> CA wrote: > My homebrew RLB uses a current balun. Some turns of thin 50 Ohm coax on a > ferrite core. The core is from a scrapped Siemens inductor. I have > acheived good performance between 0,1 to 200 MHz with this technique. I > first tried the twisted pair winding approach but the current balun was > far better. > > Chris SM6PXJ > > skavanagh72nospam@yahoo.ca wrote: >> I have just built an HF return loss bridge according to the info in >> "Solid State design for the Radio Amateur". While it works ok, I was >> hoping for a bit better performance. Clearly the "balun" doesn't have >> enough inductance to operate well below 10 MHz or so (10 turns bifilar >> #30 AWG enamelled wire on Amidon T23-43, as specified in the book - >> twisted pair, which isn't specified one way or the other in the >> book). This can probably be largely fixed by using a larger ferrite >> core (T37-43's available in junkbox). I am interested primarily in >> the >> 1.8-50 MHz range, though I wouldn't complain if it worked on 2m too. >> >> But even at 30 MHz a reasonably good microwave 50 ohm load gives only >> about 28 dB apparent return loss...Not bad, but I might have expected >> a bit more. >> >> And an open and short give about 2 dB different signal levels at 30 >> MHz. That is with big pads (>20 dB attenuation) on both the signal >> generator and detector. The detector is an HF receiver with a step >> attenuator used to maintain a constant S-meter reading. >> >> The circuit is built on a small PC board using construction techniques >> typical for the UHF or low microwave range (except that the test port >> connector is an SO-239), and is enclosed in a shielded box. Each of >> the three 50 ohm resistors is made of two 100 ohm 1206 chip resistors >> in parallel and measures between 50.0 and 50.3 ohms at DC. >> >> Has anyone with experience with this circuit any suggestions for how >> to tweak it for best performance ? What accuracy level have you >> achieved ? Do you know where I might find an error analysis for this >> circuit ? Or if I am to think about errors myself, does anyone know >> how to model the balun in SPICE ? >> >> 73, >> Steve VE3SMA If you could give more details of how to build your circuit, or a photo of it, I'd appreciate that. Chris Article: 96889 of rec.radio.amateur.homebrew From: Dr. Anton T. Squeegee Subject: Re: In the interests of historical accuracy: Case White Date: Sat, 18 Mar 2006 22:56:54 -0800 Message-ID: References: <4oq712df168pnt2pqt68ujg19hulruu7ts@4ax.com> In article <4oq712df168pnt2pqt68ujg19hulruu7ts@4ax.com>, Aero.Spike@S&T.invalid (known to some as Spike) scribed... > Invasion of Poland (Fall Weiss) You have the wrong newsgroup(s). This is rec.radio.amateur.homebrew, a forum for discussing the design, construction, and troubleshooting of home-built electronic widgets relating to the amateur radio service. Nowhere in your missive did I detect anything that would remotely relate to that topic. -- Dr. Anton T. Squeegee, Director, Dutch Surrealist Plumbing Institute (Known to some as Bruce Lane, KC7GR) http://www.bluefeathertech.com -- kyrrin a/t bluefeathertech d-o=t calm "Salvadore Dali's computer has surreal ports..." Article: 96890 of rec.radio.amateur.homebrew From: "Norm Mann" References: <1142759754.023586.94940@i40g2000cwc.googlegroups.com> Subject: Re: MHW707-2 is it linear ? Message-ID: Date: Sun, 19 Mar 2006 13:02:31 GMT "MarkAren" wrote in message news:1142759754.023586.94940@i40g2000cwc.googlegroups.com... > Hi All, > > I have just found my small stash of these devices along with the Mot > data book. It isn't clear reading the datasheet if this is capable of > linear, or is only class C. > > Any ideas ? > If it's in the same family as MHW710-x, modulating the input with a linear signal will produce a linear signal at the output, but keep an eye on the drive level and watch for self-oscillations. The MHW710 has been used in ATV applications, which is AM and often has an FM subcarrier too. -NM