[AMRadio] RE: homebrew receiver progress
Hello all AM,ers. I have been making great progress on the second homebrew superhet receiver. I have the chassis all punched out, holes drilled, and primed and painted light gray to match the push pull transmitter. Front panel is drilled and painted black. Last night I mounted the transformers, chokes, tube sockets, IF cans, bfo crystal, terminal strips, filter board, lo coil and switch box, and output jacks for audio, mute, IF output (for scope), antenna hookup. I have to add the handles to the front panel, paint the side supports, then I can center and mount the tuning cap and preselector cap, install the controls and switches. I also forgot to drill holes for the s meter sensitivity and zero pots. I have a nice heathkit S meter, and will use 3 ultra bright red led's to light the meter up. I tested it, and it looks cool. The digital display is built and tested. Wiring the power supply will be first, once I have the HV, I can wire and test the LO, then the mixer, then the filter setup, then one IF amp at a time, and so on. So far, it looks very good! No extra holes from changes like the first homebrew, hope it stays that way! I am already thinking about the next project, a homebrew AM transceiver. Something running a pair of 6146 tubes, or a 4d32 (I have lots of those), simple superhet, all in a small package as possible, say dx100/32v3 size. Maybe just 40 meters, since 100 watts wont do on 80 very often. That will also make the design simple, no band switching. It should be really fun, putting both receiver and transmitter in a small package, and integrating both systems together. I am not sure if a stable homebrew vfo will be possible, I may have to go with one of the VFO kits that are available, digital frequency display, pair of KT88 mod tubes. That should keep me busy for quite some time, but sure would be fun to build and operate! I have been all fired up on ham radio and building lately! Brett N2DTS
[AMRadio] Wanted: Millen Knobs Manual
WANTED: I need two knobs and a manual copy for a Millen 90903 rack mount oscilloscope. The knobs are a rectangular bar design that flares out into a round skirt--standard Millen stuff. Any help appreciated. Thanks. 73, Don Merz, N3RHT DISCLAIMER: The information contained in this e-mail may be confidential and is intended solely for the use of the named addressee. Access, copying or re-use of the e-mail or any information contained therein by any other person is not authorized. If you are not the intended recipient please notify us immediately by returning the e-mail to the originator.(A)
RE: [AMRadio] FW: Homebrew receiver
Well, I never even seen a Squires Sanders receiver, let alone listened to one! I cant recall offhand any other receiver that used a 7360 as a mixer, but need to look in my vacuum tube receiver book, it lists all the receivers with their tube lineups. The ARRL sure liked the 7360, they used it in a lot of their receiver projects, in the 1967 handbook anyway. I suspect the cost of a 7360 was lower back then, not sure why its so expensive now, must be very rare? On the lower bands, I am not sure getting a really quiet mixer is important at all, but have not tried the other designs yet. I never realized just how noisy some receivers are till the first homebrew was done and compared it to the R390A. I guess you think its atmospheric noise, or just get used to it, but I cant stand the R390a anymore. The first homebrew receiver is VERY quiet, but is an odd design, I hope the new one is fairly quiet with the design I picked. If its not quiet, maybe I will try to duplicate the design of the first receiver using a 7 or 9 pin tube in place of the 12SA7. I am sure there is a tube to replace the 12SA7 in a miniature type. Maybe I should have planned it that way from the start, go with what you know works well, but trying other things is part of the fun... It will be easy to change the tube type if the first design does not work out (6AH6, cathode injected LO). Brett N2DTS The Squires Sanders SS-1R and SS-IBS both used a pair of 7360s. I never had a 1R, but I never thought the IBS worked noticeably better than any other relatively high end radio with more conventional vacuum tube mixer circuitry like the NC400 or the 51J4. And the thing was harder to align correctly as well (maybe that's why I won't impressed = never got it right:) Scott
Re: [AMRadio] FW: Homebrew receiver
Clegg Intercepter receiver for 6 and 2 meters also used the 7360 as a mixer. In my Squires Sanders SS-1R receiver, with no signals present and the antenna connected, the receiver is very quiet. It comes to life when you tune a signal. The receiver was not very tolerant of random length antennas or antennas that didn't provide a decent match to the frequencies you wanted to receive. The 7360 was also used as a balanced modulator in a number of 60's sweep tube SSB transceivers. Pete, wa2cwa On Thu, 06 Nov 2003 09:42:23 -0500 Brett Gazdzinski [EMAIL PROTECTED] writes: Well, I never even seen a Squires Sanders receiver, let alone listened to one! I cant recall offhand any other receiver that used a 7360 as a mixer, but need to look in my vacuum tube receiver book, it lists all the receivers with their tube lineups. The ARRL sure liked the 7360, they used it in a lot of their receiver projects, in the 1967 handbook anyway. I suspect the cost of a 7360 was lower back then, not sure why its so expensive now, must be very rare? On the lower bands, I am not sure getting a really quiet mixer is important at all, but have not tried the other designs yet. I never realized just how noisy some receivers are till the first homebrew was done and compared it to the R390A. I guess you think its atmospheric noise, or just get used to it, but I cant stand the R390a anymore. The first homebrew receiver is VERY quiet, but is an odd design, I hope the new one is fairly quiet with the design I picked. If its not quiet, maybe I will try to duplicate the design of the first receiver using a 7 or 9 pin tube in place of the 12SA7. I am sure there is a tube to replace the 12SA7 in a miniature type. Maybe I should have planned it that way from the start, go with what you know works well, but trying other things is part of the fun... It will be easy to change the tube type if the first design does not work out (6AH6, cathode injected LO). Brett N2DTS The Squires Sanders SS-1R and SS-IBS both used a pair of 7360s. I never had a 1R, but I never thought the IBS worked noticeably better than any other relatively high end radio with more conventional vacuum tube mixer circuitry like the NC400 or the 51J4. And the thing was harder to align correctly as well (maybe that's why I won't impressed = never got it right:) Scott The best thing to hit the internet in years - Juno SpeedBand! Surf the web up to FIVE TIMES FASTER! Only $14.95/ month - visit www.juno.com to sign up today!
Re: [AMRadio] FW: Homebrew receiver
Hi Pete, Congratulations on the SS-1R! Do you have the panadaptor for it too? A friend has them both and they're quite an interesting set up. I have an Interceptor and Interceptor II and I seem to remember that one of them uses the 7360 as a mixer. However, I think it mixes the output of a crystal oscillator with the VFO -- like Drake does in the 4 line -- rather than using the tube as the first conversion mixer. Of course the Interceptor is basically a 6m receiver with built-in 2m meter convertor, but I'm referring to the convertor in the main or 6m receiver. I have an RCA receiving tube manual from 1971 that describes the application of the 7360 as a balanced modulator or mixer. I think the tube can work very well, but requires attention to power supply purity and lead dress to maintain balance in the circuit. 73, Ed N3CMI [EMAIL PROTECTED] m Sent by: To [EMAIL PROTECTED] amradio@mailman.qth.net lman.qth.net cc Subject 11/06/2003 01:37 Re: [AMRadio] FW: Homebrew receiver PM Please respond to [EMAIL PROTECTED] th.net Clegg Intercepter receiver for 6 and 2 meters also used the 7360 as a mixer. In my Squires Sanders SS-1R receiver, with no signals present and the antenna connected, the receiver is very quiet. It comes to life when you tune a signal. The receiver was not very tolerant of random length antennas or antennas that didn't provide a decent match to the frequencies you wanted to receive. The 7360 was also used as a balanced modulator in a number of 60's sweep tube SSB transceivers. Pete, wa2cwa On Thu, 06 Nov 2003 09:42:23 -0500 Brett Gazdzinski [EMAIL PROTECTED] writes: Well, I never even seen a Squires Sanders receiver, let alone listened to one! I cant recall offhand any other receiver that used a 7360 as a mixer, but need to look in my vacuum tube receiver book, it lists all the receivers with their tube lineups. The ARRL sure liked the 7360, they used it in a lot of their receiver projects, in the 1967 handbook anyway. I suspect the cost of a 7360 was lower back then, not sure why its so expensive now, must be very rare? On the lower bands, I am not sure getting a really quiet mixer is important at all, but have not tried the other designs yet. I never realized just how noisy some receivers are till the first homebrew was done and compared it to the R390A. I guess you think its atmospheric noise, or just get used to it, but I cant stand the R390a anymore. The first homebrew receiver is VERY quiet, but is an odd design, I hope the new one is fairly quiet with the design I picked. If its not quiet, maybe I will try to duplicate the design of the first receiver using a 7 or 9 pin tube in place of the 12SA7. I am sure there is a tube to replace the 12SA7 in a miniature type. Maybe I should have planned it that way from the start, go with what you know works well, but trying other things is part of the fun... It will be easy to change the tube type if the first design does not work out (6AH6, cathode injected LO). Brett N2DTS The Squires Sanders SS-1R and SS-IBS both used a pair of 7360s. I never had a 1R, but I never thought the IBS worked noticeably better than any other relatively high end radio with more conventional vacuum tube mixer circuitry like the NC400 or the 51J4. And the thing was harder to align correctly as well (maybe that's why I won't impressed = never got it right:) Scott The best thing to hit the internet in years - Juno SpeedBand! Surf the web up to FIVE TIMES FASTER! Only $14.95/ month - visit www.juno.com to sign up today! ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
RE: [AMRadio] FW: Homebrew receiver
The Gonset G76 also uses the 7360. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Thursday, November 06, 2003 1:37 PM To: amradio@mailman.qth.net Subject: Re: [AMRadio] FW: Homebrew receiver Clegg Intercepter receiver for 6 and 2 meters also used the 7360 as a mixer. In my Squires Sanders SS-1R receiver, with no signals present and the antenna connected, the receiver is very quiet. It comes to life when you tune a signal. The receiver was not very tolerant of random length antennas or antennas that didn't provide a decent match to the frequencies you wanted to receive. The 7360 was also used as a balanced modulator in a number of 60's sweep tube SSB transceivers. Pete, wa2cwa On Thu, 06 Nov 2003 09:42:23 -0500 Brett Gazdzinski [EMAIL PROTECTED] writes: Well, I never even seen a Squires Sanders receiver, let alone listened to one! I cant recall offhand any other receiver that used a 7360 as a mixer, but need to look in my vacuum tube receiver book, it lists all the receivers with their tube lineups. The ARRL sure liked the 7360, they used it in a lot of their receiver projects, in the 1967 handbook anyway. I suspect the cost of a 7360 was lower back then, not sure why its so expensive now, must be very rare? On the lower bands, I am not sure getting a really quiet mixer is important at all, but have not tried the other designs yet. I never realized just how noisy some receivers are till the first homebrew was done and compared it to the R390A. I guess you think its atmospheric noise, or just get used to it, but I cant stand the R390a anymore. The first homebrew receiver is VERY quiet, but is an odd design, I hope the new one is fairly quiet with the design I picked. If its not quiet, maybe I will try to duplicate the design of the first receiver using a 7 or 9 pin tube in place of the 12SA7. I am sure there is a tube to replace the 12SA7 in a miniature type. Maybe I should have planned it that way from the start, go with what you know works well, but trying other things is part of the fun... It will be easy to change the tube type if the first design does not work out (6AH6, cathode injected LO). Brett N2DTS The Squires Sanders SS-1R and SS-IBS both used a pair of 7360s. I never had a 1R, but I never thought the IBS worked noticeably better than any other relatively high end radio with more conventional vacuum tube mixer circuitry like the NC400 or the 51J4. And the thing was harder to align correctly as well (maybe that's why I won't impressed = never got it right:) Scott The best thing to hit the internet in years - Juno SpeedBand! Surf the web up to FIVE TIMES FASTER! Only $14.95/ month - visit www.juno.com to sign up today! ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio DISCLAIMER: The information contained in this e-mail may be confidential and is intended solely for the use of the named addressee. Access, copying or re-use of the e-mail or any information contained therein by any other person is not authorized. If you are not the intended recipient please notify us immediately by returning the e-mail to the originator.(A)
RE: [AMRadio] FW: Homebrew receiver
I cant recall offhand any other receiver that used a 7360 as a mixer, but need to look in my vacuum tube receiver book, it lists all the receivers with their tube lineups. The ARRL sure liked the 7360, they used it in a lot of their receiver projects, in the 1967 handbook anyway. I suspect the cost of a 7360 was lower back then, not sure why its so expensive now, must be very rare? I still have a few that I bought new back in mid 70's for about $12 each. There are a couple of beam deflection tubes similar to the 7360, made for TV applications. I believe one is the 6AR8, and there is another one without the wierd filament connection, but I forget the type number. The 7360 was used as a mixer in the Tempo One (an early, very flaky, Yaesu tube type SSB transceiver). In later models they replaced the 7360 with some kind of solid state mixer. The tube is probably expensive because it is rare, while there is equipment still in use that requires it. I once built a SSB generator using one as a balanced mixer. I successfully got it working, generating a near-hifi SSB signal at 64 kc/s using a Collins multiplexing asymmetrical mechanical filter from Ma Bell as the sideband filter. I lost interest in the project before building converter stages to translate the low-frequency signal to the amateur frequencies. I never realized just how noisy some receivers are till the first homebrew was done and compared it to the R390A. I guess you think its atmospheric noise, or just get used to it, but I cant stand the R390a anymore. The problem with the R-390A is that there are so many mixer stages ahead of the selectivity. Every mixer contributes to noise. The ultimate design for a practical receiver would be single conversion with no rf stage ahead of the mixer. It would use a selective enough front-end tuning network between the antenna and mixer to reject images, and the mixer would be low noise enough to hear all the way down to the atmospreric noise floor. The mixer would have high enough output level to feed directly into the selectivity filter with no amplifier stage between the mixer and filter. Following the filter, the i-f amplifier would be low noise and high gain enough to boost the signal to the level needed at the detector without raising the noise floor above that of the signal that exits the filter. One requirement would be a selectivity filter with minimal insertion loss. One interesting receiver design from before WWII used a separate tuned circuit to null out the image frequency. It was written up in QST, I believe (or was it RADIO?). Hallicrafters came out with a model or two that used the design, but it was swiftly discontinued. I think the problem was that the image null had to be a separate control from the main tuning because of the difficulty of getting the image null to accurately track with the rest of the receiver. This might be a worthwhile topic to research and apply to a no-compromise homebrew receiver. I am sure there is a tube to replace the 12SA7 in a miniature type. Zillions of them were used in the miniature tube version of the classic 5-tube ac/dc bc receiver. Isn't it a 12BE6? (My computer is in the house and all my radio reference material is out in the shack). Every commercially built receiver, ham or military, is one big compromise, designed to best meet the needs of diverse users. Don K4KYV _ Is your computer infected with a virus? Find out with a FREE computer virus scan from McAfee. Take the FreeScan now! http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963
RE: [AMRadio] RE: homebrew receiver progress
Eddy, I do have some Bill Orr handbooks, good stuff in there. I built the power supplies, both the high voltage and low voltage and wired up all the filaments on the homebrew receiver tonight. Still some work to do on the power, I need to get a low voltage for the frequency display backlight and S meter led's. A really stable homebrew vfo might be hard for me. The LO in the receiver is ok, once it warms up, so maybe it can be done. There used to be a company that made a kit, a DDS vfo, with memories and so on, which would be cool, but I cant find it anymore, I think it was S+S who sold it. Tubes and caps are more fun anyway. Brett N2DTS Hi Brett... Just goes to show you can't keep a good man down! Hi Hi You sure are a prolific builder! If you have any of the old Bill Orr RADIO HANDBOOKs from the 1950's, Brett, he featured neat mono-band AM transceivers therein---I recall (was it the '58 edition..?) he had a neat 10-meter design, but it was strictly low power. Still a nice package, though, on 10 who needs QRO anyway...? Building a stable, homebrew VFO is NOT an impossible task---in fact, there was an excellent piece by Walt Hutchens in an older ELECTRIC RADIO magazine that tackled this very project. A few months back I built a HB VFO for 40-meters that used NO SOLID DIELECTRIC CAPACITORS WHATEVER---everything was air dielectric. Even the coil was an air core BW miniductor! This I did to try eliminate/minimize drift over time without worry about NPO caps, etc. etc. It worked, too, in the short run---really stable for the first two hours, or so, but then it started to drift ever so slowly. Anyway, it was a fun experiment... Good luck with yours! ~73!~ Eddy VE3CUI - VE3XZ
