- 1. [Amps] 50 MHz QSK relays for converted SB-220 (score: 1)
- Author: "Bill W5WVO" <w5wvo@cybermesa.net>
- Date: Sun, 10 May 2009 11:52:27 -0600
- I have a 6m-converted SB-220, and I want to replace the frame relay with QSK-capable relays. What relay(s) have people used for this application successfully? Where can they be obtained? How much? Th
- /archives//html/Amps/2009-05/msg00052.html (6,523 bytes)
- 2. Re: [Amps] Silver epoxy yes (score: 1)
- Author: "Bill W5WVO" <w5wvo@cybermesa.net>
- Date: Thu, 28 May 2009 20:34:59 -0600
- I don't get it. Why not just Google "silver epoxy"? You get a ton of hits. This stufff is easy to find. Bill W5WVO _______________________________________________ Amps mailing list Amps@contesting.co
- /archives//html/Amps/2009-05/msg00253.html (9,950 bytes)
- 3. Re: [Amps] AL1200, RTTY contesting, temps, duty cycles (not 100%) (score: 1)
- Author: "Bill W5WVO" <w5wvo@cybermesa.net>
- Date: Sat, 4 Jul 2009 17:14:29 -0600
- I suppose right up there with RTTY is WSJT with its mode-defined 50% transmit cycles (30 seconds "on" for FSK441/JT6M, 60 seconds "on" for JT65). I'm running a 6-meter-converted SB-220 with new match
- /archives//html/Amps/2009-07/msg00097.html (17,389 bytes)
- 4. Re: [Amps] grounding grids (score: 1)
- Author: "Bill W5WVO" <w5wvo@cybermesa.net>
- Date: Wed, 29 Jul 2009 10:57:59 -0600
- How would you characterize, then, the design of the SB-220, where the 3-500Z grids are grounded through RFCs and bypassed by dsk ceramic caps? Particularly since this particular amplifier has been co
- /archives//html/Amps/2009-07/msg00360.html (11,826 bytes)
- 5. Re: [Amps] grounding grids (score: 1)
- Author: "Bill W5WVO" <w5wvo@cybermesa.net>
- Date: Wed, 29 Jul 2009 20:26:35 -0600
- _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
- /archives//html/Amps/2009-07/msg00382.html (20,524 bytes)
- 6. Re: [Amps] grounding grids (score: 1)
- Author: "Bill W5WVO" <w5wvo@cybermesa.net>
- Date: Wed, 29 Jul 2009 20:27:17 -0600
- In the SB-220, cutoff bias (during "receive" periods) of +130V is applied to the cathodes of the 3-500Zs via the center-tap of the filament transformer, thus placing the potential of the grounded con
- /archives//html/Amps/2009-07/msg00383.html (20,667 bytes)
- 7. Re: [Amps] grounding grids (score: 1)
- Author: "Bill W5WVO" <w5wvo@cybermesa.net>
- Date: Thu, 30 Jul 2009 11:53:02 -0600
- So there seems to be some difference of opinion as to whether the Heath SB-220 grid-grounding implementation actually suipplies negative feedback or not, actually reduces IMD components in the output
- /archives//html/Amps/2009-07/msg00409.html (11,425 bytes)
- 8. Re: [Amps] Silver Plating Tank Coil ?? (score: 1)
- Author: "Bill W5WVO" <w5wvo@cybermesa.net>
- Date: Sat, 19 Sep 2009 21:41:30 -0600
- Brings to mind a young (then) guy I knew in Beverly Hills CA back in the 1970s who built custom 4-1000A amplifiers for a few of the big-gun California DXers and contesters. They were absolute works o
- /archives//html/Amps/2009-09/msg00249.html (8,343 bytes)
- 9. Re: [Amps] PEP Reading Wattmeter (score: 1)
- Author: "Bill W5WVO" <w5wvo@cybermesa.net>
- Date: Thu, 1 Oct 2009 17:40:53 -0600
- I haven't calibrated it or anything -- just as-is out of box -- but the Daiwa CN-801HP has worked well for me. I work mostly 6 meters, and it seems fairly accurate on that band. It compares closely w
- /archives//html/Amps/2009-10/msg00005.html (8,523 bytes)
- 10. Re: [Amps] Pictures of number 1 (score: 1)
- Author: "Bill W5WVO" <w5wvo@cybermesa.net>
- Date: Thu, 8 Oct 2009 17:41:30 -0600
- There are two extraneous spaces in the URL. The correct URL is: http://home.comcast.net/~kg7hf/6m_3cx800a7_amp/build%20pictures/PIC_0247.JPG Bill W5WVO _______________________________________________
- /archives//html/Amps/2009-10/msg00144.html (9,991 bytes)
- 11. Re: [Amps] Pictures of number 1 (score: 1)
- Author: "Bill W5WVO" <w5wvo@cybermesa.net>
- Date: Thu, 8 Oct 2009 17:49:53 -0600
- Same problem with the other URLs -- remove space after "http" and before "JPG" Bill _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/m
- /archives//html/Amps/2009-10/msg00145.html (10,569 bytes)
- 12. [Amps] Step-start and 3-500Z filament life (score: 1)
- Author: "Bill W5WVO" <w5wvo@cybermesa.net>
- Date: Sat, 5 Dec 2009 20:41:35 -0700
- I understand why turning a tube's filaments off and on repeatedly shortens the tube's useful life. However, I'm not clear about the effects of doing this when a step-start circuit is included (as in
- /archives//html/Amps/2009-12/msg00143.html (6,995 bytes)
- 13. Re: [Amps] Conservation of Energy! (score: 1)
- Author: "Bill W5WVO" <w5wvo@cybermesa.net>
- Date: Sun, 6 Dec 2009 08:03:22 -0700
- [Sigh] Ham radio hasn't been "based on being technically astute" in a long time. The FCC currently states that the sole reason for license examinations is to try to ensure that licensees can operate
- /archives//html/Amps/2009-12/msg00159.html (9,817 bytes)
- 14. Re: [Amps] 3-500z Plate voltage... (score: 1)
- Author: "Bill W5WVO" <w5wvo@cybermesa.net>
- Date: Fri, 11 Dec 2009 18:29:27 -0700
- Yup, can confirm this from experience. Get rid of that bad boy, it is trouble waiting to happen. Bill W5WVO If you have one arcing you have one going - probably gassy, though it could be a warped gri
- /archives//html/Amps/2009-12/msg00303.html (7,242 bytes)
- 15. [Amps] Alternative cooling strategies for SB-220? (score: 1)
- Author: "Bill W5WVO" <w5wvo@cybermesa.net>
- Date: Tue, 15 Dec 2009 16:18:10 -0700
- I have a 6-meter-converted SB-220 equipped with the upgraded Harbaugh cooling fan, which provides more air circulation volume than the original Heathkit fan. It does a great job, but sounds like a B-
- /archives//html/Amps/2009-12/msg00348.html (7,824 bytes)
- 16. Re: [Amps] Alternative cooling strategies for SB-220? (score: 1)
- Author: "Bill W5WVO" <w5wvo@cybermesa.net>
- Date: Tue, 15 Dec 2009 17:03:01 -0700
- It already has, apparently. However, it was a serious question, despite the obvious reality that some guys think wanting to reduce the level of ambient noise in the shack is stupid. I'm sure there mu
- /archives//html/Amps/2009-12/msg00354.html (10,343 bytes)
- 17. Re: [Amps] Alternative cooling strategies for SB-220? (score: 1)
- Author: "Bill W5WVO" <w5wvo@cybermesa.net>
- Date: Thu, 17 Dec 2009 13:19:06 -0700
- After reading all the suggestions (serious and otherwise), I am left with only one really appropriate and practical option: Leave it the way it is. (a) The tubes ARE graphite anode 3-500Zs, and (b) I
- /archives//html/Amps/2009-12/msg00401.html (14,290 bytes)
- 18. Re: [Amps] Alternative cooling strategies for SB-220? (score: 1)
- Author: "Bill W5WVO" <w5wvo@cybermesa.net>
- Date: Fri, 18 Dec 2009 11:42:33 -0700
- And sacrifice 3 dB on these weak-signal modes where 3 dB is often the difference between "nil" and "solid decode"? If that's the only alternative, I'd rather listen to the fan noise. :-) But I am loo
- /archives//html/Amps/2009-12/msg00444.html (9,675 bytes)
- 19. Re: [Amps] Ameritron AL-80A Receive muted - relay? (score: 1)
- Author: "Bill W5WVO" <w5wvo@cybermesa.net>
- Date: Thu, 24 Dec 2009 09:08:23 -0700
- Have the same problem with the Harbach replacememnt TR relay in my converted SB-220, and am planning the same attack with the emery cloth once I get back from holiday vacation. Was considering buying
- /archives//html/Amps/2009-12/msg00534.html (9,003 bytes)
- 20. [Amps] Failure: SB-220 bias supply (Harbach board) (score: 1)
- Author: "Bill VanAlstyne W5WVO" <w5wvo@cybermesa.net>
- Date: Wed, 13 Jan 2010 11:13:35 -0700
- This morning I turned on my converted SB-220 6-meter amp and discovered it was not amplifying any more. A little checking with a voltmeter revealed that there was no operating bias being generated by
- /archives//html/Amps/2010-01/msg00148.html (7,832 bytes)
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