- 1. [Amps] drive power (score: 1)
- Author: "Steve Flood" <flood@ixi.net>
- Date: Sat, 17 Mar 2007 08:00:39 -0600
- As I muddle through the understanding of amp design, there is a remaining topic that is confusing me - in regard to matching drive power to the exciter (in this case a modern 100w transceiver). I und
- /archives//html/Amps/2007-03/msg00196.html (7,614 bytes)
- 2. Re: [Amps] drive power (score: 1)
- Author: "EP Swynar" <gswynar@durham.net>
- Date: Sat, 17 Mar 2007 10:30:05 -0500
- On St. Patrick's Day Steve wrote... Do I next assume that I need 4 813's match my transceivers 100w max ouput level? With what have folks been driving all those homebrew 2x813 amps over the years? **
- /archives//html/Amps/2007-03/msg00197.html (7,414 bytes)
- 3. Re: [Amps] drive power (score: 1)
- Author: "Dan Hearn" <dhearn@air-pipe.com>
- Date: Sat, 17 Mar 2007 08:15:06 -0700
- Steve, You are fortunate to have some excess drive power. The distortion in your exciter will be greater at 100w out than it will be at 50 or 60 w out. Turn the drive down on your exciter. Most moder
- /archives//html/Amps/2007-03/msg00198.html (9,110 bytes)
- 4. Re: [Amps] drive power (score: 1)
- Author: Karl-Arne Markström <sm0aom@telia.com>
- Date: Sat, 17 Mar 2007 16:15:19 +0100
- The drive power ratings for different circuits (grid-driven and cathode-driven) may look confusing. In the grid-driven AB1 circuit, you only need drive voltage which corresponds to sufficient power t
- /archives//html/Amps/2007-03/msg00199.html (11,126 bytes)
- 5. Re: [Amps] drive power (score: 1)
- Author: "Steve Flood" <flood@ixi.net>
- Date: Sat, 17 Mar 2007 09:41:22 -0600
- Perhaps I was getting lost or misinterpreting this information from Tom, W8JI: http://www.w8ji.com/loading_amplifier.htm When I read this I conclude that my exciter (TS-870S) should be run to full 10
- /archives//html/Amps/2007-03/msg00201.html (6,980 bytes)
- 6. Re: [Amps] drive power (score: 1)
- Author: "Paul Christensen" <w9ac@arrl.net>
- Date: Sat, 17 Mar 2007 13:13:59 -0400
- Unlike many other transceivers, the TS-870S exhibits low ALC overshoot at low transmit output levels, particularly when the Drive/Mic level is set to reflect very little ALC action. On CW, I apply o
- /archives//html/Amps/2007-03/msg00202.html (7,945 bytes)
- 7. Re: [Amps] drive power (score: 1)
- Author: "Tom W8JI" <w8ji@w8ji.com>
- Date: Sat, 17 Mar 2007 13:49:35 -0400
- ALC response in most rigs is terrible. It especially gets worse when output power is reduced. My FT1000D doesn't have that problem at all (since it has a real drive control) , but my ICOM 706 and 77
- /archives//html/Amps/2007-03/msg00203.html (9,811 bytes)
- 8. Re: [Amps] drive power (score: 1)
- Author: "Tom W8JI" <w8ji@w8ji.com>
- Date: Sat, 17 Mar 2007 13:52:42 -0400
- If an amp requires very low drive and is driven by a 100 watt exciter, it is a very poor system. Sometimes people think it improves distortion, but it often does just the opposite. 73 Tom __________
- /archives//html/Amps/2007-03/msg00205.html (7,565 bytes)
- 9. Re: [Amps] drive power (score: 1)
- Author: "Bert Almemo" <balmemo@sympatico.ca>
- Date: Sat, 17 Mar 2007 15:56:04 -0400
- Hi Tom, What you're saying makes sense. I have an IC-746 driving an IC-2KL and that amp needs about 35-40 watts drive. I'm reducing the drive but maybe that's not the way to go. Any ideas? 73 Bert, V
- /archives//html/Amps/2007-03/msg00206.html (8,907 bytes)
- 10. Re: [Amps] drive power (score: 1)
- Author: Steve Thompson <g8gsq@eltac.co.uk>
- Date: Sat, 17 Mar 2007 21:28:00 +0000
- Bert Almemo wrote: Hi Tom, What you're saying makes sense. I have an IC-746 driving an IC-2KL and that amp needs about 35-40 watts drive. I'm reducing the drive but maybe that's not the way to go. An
- /archives//html/Amps/2007-03/msg00208.html (7,896 bytes)
- 11. Re: [Amps] drive power (score: 1)
- Author: "Paul Elliott" <paab@valornet.com>
- Date: Sat, 17 Mar 2007 17:21:02 -0600
- I have a homemade 8877 amplifier that covers 160, 80, 40, and 20 m and used almost exclusively on cw. The power supply puts out a very stout 4000 vdc. The grid overcurrent protection circuit is set t
- /archives//html/Amps/2007-03/msg00209.html (8,381 bytes)
- 12. Re: [Amps] drive power (score: 1)
- Author: "Tom W8JI" <w8ji@w8ji.com>
- Date: Sat, 17 Mar 2007 20:35:10 -0400
- The Orion is very good about not having any overshoot on CW. After the first Morse element on a band it sets the transmitter gain. This is necessary so the Orion has a good waveform and does not cli
- /archives//html/Amps/2007-03/msg00210.html (8,603 bytes)
- 13. Re: [Amps] drive power (score: 1)
- Author: "Tom W8JI" <w8ji@w8ji.com>
- Date: Sat, 17 Mar 2007 20:45:03 -0400
- What you're saying makes sense. I have an IC-746 driving an IC-2KL and that amp needs about 35-40 watts drive. I'm reducing the drive but maybe that's not the way to go. Any ideas? I use an attenuato
- /archives//html/Amps/2007-03/msg00211.html (8,315 bytes)
- 14. Re: [Amps] drive power (score: 1)
- Author: Gudguyham@aol.com
- Date: Sun, 18 Mar 2007 11:37:05 EDT
- Some years ago a couple of contester friends of mine who were running the Icom 781 (don't remember the # but it was the top of the line radio then) They both were running Aplha amps using tetrodes I
- /archives//html/Amps/2007-03/msg00214.html (8,179 bytes)
- 15. Re: [Amps] drive power (score: 1)
- Author: "Robert Bonner" <rbonner@qro.com>
- Date: Sun, 18 Mar 2007 13:22:28 -0500
- Lou, Yes good old Icom and the 781 overshoot problem. The amps were Alpha 87A's (3CX800's) and the 781. The spike would send 200+ Watts on the first syllable to the amplifier and it would BLOW out th
- /archives//html/Amps/2007-03/msg00215.html (10,542 bytes)
- 16. Re: [Amps] drive power (score: 1)
- Author: "Win" <w0lz@winlyn.us>
- Date: Mon, 19 Mar 2007 22:17:08 -0500
- I hate to come back to this subject, but I am not sure I understand the problem. Is the overshoot a product of the ALC outputted from the exciter to the amp, or is it caused within the transceiver at
- /archives//html/Amps/2007-03/msg00227.html (8,296 bytes)
- 17. Re: [Amps] drive power (score: 1)
- Author: Vic K2VCO <vic@rakefet.com>
- Date: Mon, 19 Mar 2007 20:45:33 -0700
- It's caused by the ALC loop in the transceiver, not the ALC connection to the amp. When you reduce power with a power level control, what you are doing is setting the point at which the internal ALC
- /archives//html/Amps/2007-03/msg00228.html (9,350 bytes)
- 18. Re: [Amps] drive power (score: 1)
- Author: rgroh@swbell.net
- Date: Mon, 19 Mar 2007 20:50:45 -0700 (PDT)
- I think the problem being alluded to is a burst of RF (at full output) from the transmitter/transceiver which happens before the ALC can cut in and reduce it to the proper level. If the designer does
- /archives//html/Amps/2007-03/msg00229.html (9,290 bytes)
- 19. Re: [Amps] drive power (score: 1)
- Author: "Robert Bonner" <rbonner@qro.com>
- Date: Mon, 19 Mar 2007 23:24:49 -0500
- That's sort of true, but not always true Bob, for instance the IC-781 would unload with a 300W spike when it felt like it and it was only a 150watt radio. My amp would run at full power at 150Watts b
- /archives//html/Amps/2007-03/msg00232.html (10,783 bytes)
- 20. Re: [Amps] drive power (score: 1)
- Author: "Tom W8JI" <w8ji@w8ji.com>
- Date: Tue, 20 Mar 2007 00:51:51 -0400
- It's largely an internal function of the radio. All radios have a finite time before ALC activates. Nearly all radios use the ALC as a power control. Some radios are so slow the ALC cannot respond f
- /archives//html/Amps/2007-03/msg00233.html (12,312 bytes)
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