- 21. Re: [Amps] ALPHAs and momentary power outages (score: 1)
- Author: "Dick Green WC1M" <wc1m@msn.com>
- Date: Mon, 16 Jul 2007 09:44:18 -0400
- I have an 87A and 2000A here, too, and have always liked the 2000A's short warmup after power down and immediate restart. I'm virtually certain the three-minute timer is implemented in the 87A firmwa
- /archives//html/Amps/2007-07/msg00264.html (9,209 bytes)
- 22. Re: [Amps] ALPHAs and momentary power outages (score: 1)
- Author: "Dick Green WC1M" <wc1m@msn.com>
- Date: Wed, 18 Jul 2007 11:27:10 -0400
- outside the I'm glad someone was paying attention. It would be hard to reprogram the microprocessor, but it would be easy to patch the timer value on the fly, as needed. You just have to get the add
- /archives//html/Amps/2007-07/msg00323.html (10,192 bytes)
- 23. Re: [Amps] ALPHAs and momentary power outages (score: 1)
- Author: "Dick Green WC1M" <wc1m@msn.com>
- Date: Wed, 18 Jul 2007 13:35:09 -0400
- It's the latter. The microprocessor runs off it's own 110VAC transformer and power supply, independent of the main transformer and HV/LV supplies for the amp. It would be relatively easy to reroute t
- /archives//html/Amps/2007-07/msg00329.html (11,507 bytes)
- 24. Re: [Amps] ALPHAs and momentary power outages (score: 1)
- Author: "Dick Green WC1M" <wc1m@msn.com>
- Date: Wed, 18 Jul 2007 13:52:39 -0400
- Yes, the 87A uses simple analog op-amp sensors to monitor the supply voltages. The sensors can be hacked to fool the CPU into thinking all the supply voltages are at nominal values, but there are qui
- /archives//html/Amps/2007-07/msg00330.html (13,655 bytes)
- 25. Re: [Amps] ALPHAs and momentary power outages (score: 1)
- Author: "Dick Green WC1M" <wc1m@msn.com>
- Date: Wed, 18 Jul 2007 15:12:49 -0400
- John, you would know better than me about that! Seriously, Alpha has handed out firmware patch information on occasion. I know they've told customers how to calibrate the band switch by patching the
- /archives//html/Amps/2007-07/msg00332.html (10,720 bytes)
- 26. Re: [Amps] ALPHAs and momentary power outages (score: 1)
- Author: "Dick Green WC1M" <wc1m@msn.com>
- Date: Thu, 19 Jul 2007 11:54:34 -0400
- Alpha hasn't made any changes to the 87A since AlphaMax dynamic tuning was introduced back in the late 90s. Like I said, there's probably not enough code space left in the ROM to make any significant
- /archives//html/Amps/2007-07/msg00345.html (9,008 bytes)
- 27. Re: [Amps] Alpha 89 Fuse Blowing (score: 1)
- Author: "Dick Green WC1M" <wc1m@msn.com>
- Date: Mon, 6 Aug 2007 15:17:16 -0400
- Sounds like a gassy tube. I had a similar problem with my 87A. I replaced one of the original tubes because the amp was periodically failing with a filament current fault. Then the amp started gettin
- /archives//html/Amps/2007-08/msg00013.html (11,446 bytes)
- 28. Re: [Amps] Alpha 89 Fuse Blowing (score: 1)
- Author: "Dick Green WC1M" <wc1m@msn.com>
- Date: Mon, 6 Aug 2007 15:33:27 -0400
- An HV surge resistor is shown on the 87A schematic: 25W 10-ohm. Haven't pulled the cover of mine, but I'd bet it's an enamel wire wound. Wouldn't expect anything less from a top-of-the-line amp desig
- /archives//html/Amps/2007-08/msg00015.html (14,692 bytes)
- 29. Re: [Amps] Alpha 89 Fuse Blowing (score: 1)
- Author: "Dick Green WC1M" <wc1m@msn.com>
- Date: Mon, 6 Aug 2007 15:38:42 -0400
- An HV surge resistor is shown on the 87A schematic: 25W 10-ohm. Haven't pulled the cover of mine, but I'd bet it's an enamel wire wound. Wouldn't expect anything less from a top-of-the-line amp desig
- /archives//html/Amps/2007-08/msg00016.html (14,707 bytes)
- 30. Re: [Amps] Alpha 89 Fuse Blowing (score: 1)
- Author: "Dick Green WC1M" <wc1m@msn.com>
- Date: Mon, 6 Aug 2007 15:43:59 -0400
- An HV surge resistor is shown on the 87A schematic: 25W 10-ohm. Haven't pulled the cover of mine, but I'd bet it's an enamel wire wound. Wouldn't expect anything less from a top-of-the-line amp desig
- /archives//html/Amps/2007-08/msg00017.html (14,510 bytes)
- 31. Re: [Amps] [Fwd: Re: LK 500 ZA heat] (score: 1)
- Author: "Dick Green WC1M" <wc1m@msn.com>
- Date: Wed, 15 Aug 2007 12:55:09 -0400
- or and I haven't had my LK500ZC as long as Carl, but I never had a "parasitic" problem with mine, either. I had lots of other problems, most of which were the result of errors and mishaps on the par
- /archives//html/Amps/2007-08/msg00091.html (9,838 bytes)
- 32. Re: [Amps] Alpha 87 schematics (score: 1)
- Author: "Dick Green WC1M" <wc1m@msn.com>
- Date: Tue, 11 Dec 2007 22:56:16 -0500
- Ulf, If it's any help, I have the same schematics as you do, and my amp was manufactured in 1995. I believe the schematics came with the amp or I got them from Alpha shortly after purchase. The amp y
- /archives//html/Amps/2007-12/msg00135.html (8,552 bytes)
- 33. Re: [Amps] Keying the LK550ZC (score: 1)
- Author: "Dick Green WC1M" <wc1m@msn.com>
- Date: Sun, 23 Dec 2007 14:02:27 -0500
- I've successfully used QSK with the LK550ZC. It's not quite correct that the amp has to be keyed before the exciter. What's true is that the amp relay must close before the rig emits RF. How you conf
- /archives//html/Amps/2007-12/msg00219.html (10,382 bytes)
- 34. Re: [Amps] Alpha 87A Tubes 3CX800A7 and the 3CX P 800A7 (score: 1)
- Author: "Dick Green WC1M" <wc1m@msn.com>
- Date: Tue, 1 Jan 2008 12:28:08 -0500
- Are you sure the Hi-Lo switch is in the Hi position? You'll get high grid current if it's in the Lo position, and it'll be tough to get full output. The switch should always be in the Hi position. Ty
- /archives//html/Amps/2008-01/msg00006.html (34,666 bytes)
- 35. Re: [Amps] Relays (score: 1)
- Author: "Dick Green WC1M" <wc1m@msn.com>
- Date: Sun, 30 Mar 2008 16:32:20 -0400
- Some QSK amps increase the vacuum relay coil voltage to make it switch faster -- on the order of 1-2 ms. 73, Dick WC1M _______________________________________________ Amps mailing list Amps@contestin
- /archives//html/Amps/2008-03/msg00373.html (12,445 bytes)
- 36. Re: [Amps] Alpha 87A Voltage Switch (score: 1)
- Author: "Dick Green WC1M" <wc1m@msn.com>
- Date: Sun, 4 May 2008 13:32:40 -0400
- I agree with this. Leave the switch in the HI position. I think the LO position lowers the plate voltage. A few times my HI/LO switch has been inadvertently toggled to the LO position. The symptom is
- /archives//html/Amps/2008-05/msg00036.html (10,034 bytes)
- 37. Re: [Amps] QSK connections using FT-1000D driving Alpha 87A (score: 1)
- Author: "Dick Green WC1M" <wc1m@msn.com>
- Date: Sun, 23 Nov 2008 13:29:21 -0500
- Hi Dave, First: Yes, the amp likes to have at least 6' of cable between it and the rig. I've found that using a shorter cable leads to higher input SWR on some of the bands. You can use a longer cabl
- /archives//html/Amps/2008-11/msg00231.html (9,996 bytes)
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