20070301.ba v04_n022.bam.20070301 >From ???@??? Wed Feb 28 18:00:40 2007 -0600 Date: Thu, 1 Mar 2007 00:00:06 GMT From: Old Tube Radios To: Old Tube Radios Subject: BOATANCHORS digest 4022 Message-Id: <20070301000008.79FC4187B01@srvr1.theporch.com> BOATANCHORS Digest 4022 Topics covered in this issue include: 1) Power Supply Design Software by "B. Smith" 2) Re: ARRL - end of code / duct tape by Bob Roehrig 3) Re: Lowering power supply output voltage. by Richard Post 4) Re: Lowering power supply output voltage. by "Marty Reynolds' debris field" 5) Re: ARRL - end of code / duct tape by "Arden Allen" 6) Re: Lowering power supply output voltage. by "Arden Allen" 7) I want to run the B+ at 100 volts, not 250.... by Zengmeiste@aol.com 8) Cool contact by ---------------------------------------------------------------------- Message-ID: <000501c75b42$e4f81060$731bc847@HAL1000> From: "B. Smith" To: Old Tube Radios Subject: Power Supply Design Software Date: Wed, 28 Feb 2007 09:15:17 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: 7bit Has anyone played with this software? http://www.duncanamps.com/psud2/index.html breck k4che ------------------------------ Date: Wed, 28 Feb 2007 09:44:56 -0600 (CST) From: Bob Roehrig To: Old Tube Radios Cc: Old Tube Radios Subject: Re: ARRL - end of code / duct tape Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed On Wed, 28 Feb 2007, David Stinson wrote: > If running a ship- or even the 7th Fleet- depends on 1500 > messages a day, then you have another sort of problem > and God help you if the teletype goes down > (or the balloon goes up). When I used to cruise the bands for RTTY stations, I used to tune in those multi-channel military stations (16 or more channels per carrier). Seldom were they idle. Usually one of the "outermost" channels would carry un-uncrypted AP press or sometimes weather. The rest was all encrypted "junk". I am guessing that there was not that much actual traffic and that the rest was "fill" just to keep the channels busy (probably just nonsense random characters so the bad guys would not know what was real treaffic and what was not). Bob Roehrig Aurora University Telecom dept. broehrig@aurora.edu K9EUI W9ZGP WD2XSH/19 630-844-4898 fax 630-844-4222 "Nostalgia is a thing of the past" ------------------------------ Mime-Version: 1.0 Message-Id: Date: Wed, 28 Feb 2007 12:32:14 -0500 To: Old Tube Radios From: Richard Post Subject: Re: Lowering power supply output voltage. Cc: Old Tube Radios Content-Type: text/plain; charset="us-ascii" ; format="flowed" Here's another solution if you don't want to do the choke thing. One the simplest ways of reducing voltage on a receiver B+ would be a couple of parallel night lights in series with the power transformer center tap. The ones I have draw 44 mils at 120 volts each (just a bit over 5 watts). They show a 50 mA draw at 150 volts each. (without burning out.) The radio will draw less current with less B+. Depending upon the radio, just one of these may be enough to get to your goal. Simple and easy to reverse, just short out the socket. And if there's a short in the B+ line, your new pilot light(s) becomes an easily-replaced fuse. Cheap at 4 or 5 for a dollar. Also would work on combo with a new choke in that center tap lead. I use one or two of these in series as visual fuses when I reform electrolytics with the Heath PS-4 variable supply. There are lots of other uses for small lapmps. I once used a 60 watt candelabra lamp and a small resistor in a tube base as a ballast in an old radio with 300 mA series string. Worked great and took up the initial power-on surge as if it was designed to handle the full 120 volts ;-) 73, Rich KB8TAD http://tinyurl.com/537ds At 9:32 PM -0600 2/27/07, David Stinson wrote: >OK; we've heard a basket of "it won't work." > ------------------------------ Message-ID: <1776.76.17.111.22.1172683465.squirrel@fracas.netboobie.org> Date: Wed, 28 Feb 2007 12:24:25 -0500 (EST) Subject: Re: Lowering power supply output voltage. From: "Marty Reynolds' debris field" To: Old Tube Radios Cc: "Old Tube Radios" MIME-Version: 1.0 Content-Type: text/plain;charset=iso-8859-1 Content-Transfer-Encoding: 8bit N5CM asked: > Hi Scott, > > Not being well versed in those calculations, one thought > occured to me - > > What would the calculations be for a "swinging choke" input? > Just curious. > > Ken N5CM Dear curious Ken Swinging chokes are to reduce bleeder requirements when u go from no-load to full-load Using Scott's (& arrl's 1953) formula where load=1000 x L, u see that a 5 hy choke wud be @ the 'critical level' w. 5000 ohm load. But a 5-25 jobbie wud only require 25K load to hold p-s output @ no-load. Neat, huh? & here's some BIG (drum roll) NEWS. All transformers act like swinging chokes. Real chokes have a gap to keep L same over wide load range. So A REAL WORLD SOLN. FOLLOWS: Have a H-K Festival w. 2 5881s & mf-am tuna. As rec'd had TU pwr-xfrm. Replaced same w. 350-350 thing & s-s doides. Gave 450V under load. Sorta much. So just put a 10V 2.5A xfrmr's 17 ohm primary in as input choke & voila, now 350V. Nice lunch treat. Mirabile Dictu - which translated might mean morse forever. Or watch out for the chariot. signed, not Scott but aa4rm ...has this been a thread that mighta been better called "Electronic Limbo or 'how low can you go'" ------------------------------ Message-ID: <006f01c75b66$d6929170$c4e47443@KB6NAX> From: "Arden Allen" To: Old Tube Radios Subject: Re: ARRL - end of code / duct tape Date: Wed, 28 Feb 2007 10:17:28 -0800 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit > ....redundancy ....... And nothing has more of that than the military budget process. Arden Allen KB6NAX ------------------------------ Message-ID: <007001c75b66$d763eb30$c4e47443@KB6NAX> From: "Arden Allen" To: Old Tube Radios Cc: "Old Tube Radios" Subject: Re: Lowering power supply output voltage. Date: Wed, 28 Feb 2007 10:32:38 -0800 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit I give Richard Post the credit for putting this idea into my head: To keep the hacking to a minimum the simplest effectve way to lower the B+ is to buck the B+ secondary winding with a small transformer driving a silicon bridge rectifier. Insert the bridge output in series with the B+ winding center tap, and the job is done. Use one of the multi-tapped control transformers to come up with the right bucking voltage. If the reciever has a filter choke converting to a choke input filter is a good way to start the modification. Just move the input filter cap to the other end of the choke. Then add the bucking voltage to the center tap. Arden Allen KB6NAX ------------------------------ From: Zengmeiste@aol.com Message-ID: Date: Wed, 28 Feb 2007 13:54:24 EST Subject: I want to run the B+ at 100 volts, not 250.... To: Old Tube Radios CC: W7QHO@aol.com MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_be8.112a3ede.331729e0_boundary" --part1_be8.112a3ede.331729e0_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Dennis....great solution. Not to mention you also wind up with a dandy isolation transformer, si? Nice. And thanks. 73, Terry KC9KEL ps choke goes to B+ side after the bridge, yes? q: I want to run the B+ at 100 volts, not 250. - arc5@ix.netcom.com a: Presume 6.3 vac heaters..replace power xformer with 2 6.3-V units of appropriate current ratings, connect their secondaries in parallel, run 120 vac into one primary, rectify the 120 vac from the other via full-wave bridge. With a choke input filter the DC output should be close to 100 volts.

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AOL now offers free email to everyone. --part1_be8.112a3ede.331729e0_boundary Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ---REMAINDER OF MESSAGE TRUNCATED--- * * This post contains a forbidden message format * * (such as an attached file, a v-card, HTML formatting) * * Mail Lists at theporch.com only accept PLAIN TEXT * * If your postings display this message your mail program * * is not set to send PLAIN TEXT ONLY and needs adjusting * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * --part1_be8.112a3ede.331729e0_boundary-- ------------------------------ Content-Disposition: inline Content-Transfer-Encoding: binary Mime-Version: 1.0 From: To: Old Tube Radios Subject: Cool contact Content-Type: text/plain Message-Id: <20070228224420.2BE0527D31B@filter6.e-filtering.net> Date: Wed, 28 Feb 2007 15:44:20 -0700 (MST) I had a really cool QSO this last Sunday... I had bought John Devoldere's (ON4UN) Low Band DXing Handbook (4th edition) at the Spokane WA hamfest last year but didn't ever crack it open until this past Sunday at around noon. As I was reading it, I turned on my HF station, which had last been tuned up on 20 m. I heard a strong station, slight foreign accent, really good English, it distracted me from my reading. It was none other than ON4UN himself! He is a really well-known DXer, who has 300 countries on 160 m. He almost never works phone, either, but there he was, on my radio. BA content follows: My station is modest, Drake R-4B/T-4B, 100 W out, antenna is 300 ft of insulated wire draped over the top of my single-story house, about 25 ft up, open wire feedline & Johnson Matchbox. I wanted to at least tell ON4UN of the coincidence but you know 20 m, big guns: big towers, big antennas, big amps. But, I called anyway & on abt the 6th try, he heard me in the pile up. We had a nice chat, he was tickled, so was I! I thanked him for nice job on his book (I have 3rd & 1st editions of it also). He told me had had same Drake station as mine decades ago & Matchbox, too. He also had had a Drake 2B, said he wishes he could buy one again for olde times sake. John told me to ck out the CD that comes with the handbook; it has all the s/w mentioned in the book. After the QSO, I looked and no CD! I had thought it would be pasted in a CD jacket to the inside of the book's back cover. Nada. No trace. Closer examination of the back cover shows "rub marks" of where a CD had been, inside the original shrink wrap, which wrap had disappeared from the book by the time I purchased it, from one of the many small hamfest vendors, whose name I have long forgotten, so I have no recourse with them. So, I wonder if any of you has this book & could burn me a copy of the CD. The usual remuneration applies. (BTW, this QSO reminds of one I had with Bill Orr (the antenna book guy), W6SAI, a couple of decades ago.) 73 es gud DX John Wb0EQ/VE6 ------------------------------ End of BOATANCHORS Digest 4022 ******************************