- 1. [Amps] Tuned input board on SB-220 (score: 1)
- Author: Ed Dial <diale@mindspring.com>
- Date: Wed, 22 Mar 2006 21:39:08 -0500
- Gentlemen, I need opinions from the experts that live here. I have an SB-220 that does an excellent job on the pre-WARC bands, however it doesn't like 12 and 17 meters very well, thanks to the tuned
- /archives//html/Amps/2006-03/msg00604.html (6,771 bytes)
- 2. Re: [Amps] Tuned input board on SB-220 (score: 1)
- Author: "noddie" <noddie@comcast.net>
- Date: Wed, 22 Mar 2006 19:10:22 -0800
- The AT-100AMP is what I am going to use on my SB-221, I wish it had been around when I build a tuned input board for my Clippertron L, all the other tuned input boards do not work on the WARC bands a
- /archives//html/Amps/2006-03/msg00605.html (8,523 bytes)
- 3. Re: [Amps] Tuned input board on SB-220 (score: 1)
- Author: Dino Darling <dino@k6rix.com>
- Date: Wed, 22 Mar 2006 19:19:11 -0800
- I'll be watching this thread with interest! I've got a 221 that I would like to convert to a 220! Dino - K6RIX dino@k6rix.com _______________________________________________ Amps mailing list Amps@co
- /archives//html/Amps/2006-03/msg00606.html (8,665 bytes)
- 4. Re: [Amps] Tuned input board on SB-220 (score: 1)
- Author: "noddie" <noddie@comcast.net>
- Date: Wed, 22 Mar 2006 19:26:34 -0800
- This may be a dump question, but why do you want to convert a SB-221 to a SB-220 ??? I'll be watching this thread with interest! I've got a 221 that I would like to convert to a 220! problem? Dino -
- /archives//html/Amps/2006-03/msg00607.html (8,655 bytes)
- 5. Re: [Amps] Tuned input board on SB-220 (score: 1)
- Author: Bob Nielsen <nielsen@oz.net>
- Date: Wed, 22 Mar 2006 19:45:06 -0800
- My SB-200 works fine on 12 and 17 meters as-is. I haven't checked the input VSWR, but the tuner of my TS-570D will handle it. Bob, N7XY _______________________________________________ Amps mailing li
- /archives//html/Amps/2006-03/msg00608.html (7,991 bytes)
- 6. Re: [Amps] Tuned input board on SB-220 (score: 1)
- Author: "Gary Schafer" <garyschafer@comcast.net>
- Date: Wed, 22 Mar 2006 23:22:42 -0500
- There was some discussion on this board awhile back and wasn't it decided that the tuner is actually an L network and not a PI? That would make it unsuitable as a tuned input network. 73 Gary K4FMX _
- /archives//html/Amps/2006-03/msg00609.html (10,163 bytes)
- 7. Re: [Amps] Tuned input board on SB-220 (score: 1)
- Author: "k7rdx" <k7rdx@charter.net>
- Date: Wed, 22 Mar 2006 23:09:38 -0800
- The LDG module works FB with my YC-156 AMP...Output waveform looks much better than with untuned input,however it might taks a shoehorn to fit inside the Heath amps or at least some re-positioning of
- /archives//html/Amps/2006-03/msg00610.html (11,425 bytes)
- 8. Re: [Amps] Tuned input board on SB-220 (score: 1)
- Author: "Bob Maser" <bmaser@tampabay.rr.com>
- Date: Thu, 23 Mar 2006 10:38:02 -0500
- It works FB in my Henry 4K Ultra too. It even showed me that I had a bad coax connector on the output of the amp because it started to retune everytime the connection would arc. As soon as I repaired
- /archives//html/Amps/2006-03/msg00614.html (12,975 bytes)
- 9. Re: [Amps] Tuned input board on SB-220 (score: 1)
- Author: "Gary Schafer" <garyschafer@comcast.net>
- Date: Thu, 23 Mar 2006 11:33:06 -0500
- It is the input waveform of the amp that matters, not the output wave form. 73 Gary K4FMX _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting
- /archives//html/Amps/2006-03/msg00615.html (13,138 bytes)
- 10. Re: [Amps] Tuned input board on SB-220 (score: 1)
- Author: "Gary Schafer" <garyschafer@comcast.net>
- Date: Fri, 24 Mar 2006 11:45:39 -0500
- Yes you are right they do "both matter" but my point was that with the high Q output tank circuit of the amp it is going to clean up the waveform pretty well to where I don't think you would see any
- /archives//html/Amps/2006-03/msg00637.html (15,876 bytes)
- 11. Re: [Amps] Tuned input board on SB-220 (score: 1)
- Author: "Gary Schafer" <garyschafer@comcast.net>
- Date: Fri, 24 Mar 2006 11:47:44 -0500
- With an L network if the tube impedance is lower than the driver impedance then there will be a coil to ground at the cathode rather than the needed capacitor. If the cathode impedance is higher than
- /archives//html/Amps/2006-03/msg00638.html (13,389 bytes)
- 12. Re: [Amps] Tuned input board on SB-220 (score: 1)
- Author: "k7rdx" <k7rdx@charter.net>
- Date: Fri, 24 Mar 2006 10:46:42 -0800
- But if you employ the tuner in the driver, the length of coax to the tube cathode becomes another issue. I am confident the engineers at LDG as well as those who tested their tuner boards in amps pri
- /archives//html/Amps/2006-03/msg00642.html (15,216 bytes)
- 13. Re: [Amps] Tuned input board on SB-220 (score: 1)
- Author: Roger D Johnson <n1rj@adelphia.net>
- Date: Fri, 24 Mar 2006 13:59:52 -0500
- I'd be a lot more confident if there were some published figures for IMD products using an L network vs a Pi network. We really don't need more amplifiers spewing out higher levels intermodulation pr
- /archives//html/Amps/2006-03/msg00644.html (8,823 bytes)
- 14. Re: [Amps] Tuned input board on SB-220 (score: 1)
- Author: "Gary Schafer" <garyschafer@comcast.net>
- Date: Fri, 24 Mar 2006 15:02:29 -0500
- That is exactly the point! That is why I said "you might as well use the tuner in the driver" if you don't have enough capacitance at the cathode with the L network tuner. Neither is adequate. You ca
- /archives//html/Amps/2006-03/msg00646.html (18,054 bytes)
- 15. Re: [Amps] Tuned input board on SB-220 (score: 1)
- Author: "Gary Schafer" <garyschafer@comcast.net>
- Date: Fri, 24 Mar 2006 15:20:54 -0500
- You can look in Bill Orr's handbook and he says you need 13 pf/meter of capacitance at the cathode for proper operation. That's 1040pf on 80 meters. Then figure out what L network values are needed
- /archives//html/Amps/2006-03/msg00647.html (10,593 bytes)
- 16. Re: [Amps] Tuned input board on SB-220 (score: 1)
- Author: Roger D Johnson <n1rj@adelphia.net>
- Date: Fri, 24 Mar 2006 15:35:30 -0500
- I just typed a msg to George, K6GT, and it occurred to me that an L net will not match 50 ohms to 50 ohms. It would seem to me that, if at some frequency/loading combination your amp looked like 50 o
- /archives//html/Amps/2006-03/msg00648.html (9,572 bytes)
- 17. Re: [Amps] Tuned input board on SB-220 (score: 1)
- Author: "Gary Schafer" <garyschafer@comcast.net>
- Date: Fri, 24 Mar 2006 15:43:08 -0500
- Yes Roger, I think the small tuner is a great idea also but with an L network you are limited to a specific value of L and C that you can use in order to get a match. The Q is fixed and can not be c
- /archives//html/Amps/2006-03/msg00649.html (10,458 bytes)
- 18. Re: [Amps] Tuned input board on SB-220 (score: 1)
- Author: Bill Fuqua <wlfuqu00@uky.edu>
- Date: Fri, 24 Mar 2006 15:47:23 -0500
- If the LDG tuner can match a capacitive load simply having a capacitor from cathode to ground should do. It should switch to an L network with a capacitor input and inductor coupled to the cathode an
- /archives//html/Amps/2006-03/msg00650.html (10,304 bytes)
- 19. Re: [Amps] Tuned input board on SB-220 (score: 1)
- Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
- Date: Sat, 25 Mar 2006 10:11:12 +0100 (CET)
- What is the rationale for the magic 13pF/metre? It works out as -j41....and please don't say 'because it's in Bill Orr's book!' 73 Peter G3RZP _______________________________________________ Amps mai
- /archives//html/Amps/2006-03/msg00656.html (8,196 bytes)
- 20. Re: [Amps] Tuned input board on SB-220 (score: 1)
- Author: Karl-Arne Markström <sm0aom@telia.com>
- Date: Sat, 25 Mar 2006 11:51:42 +0100
- Actually the value of 20 pF/meter (-j27) is also quoted at several places in my 1970 edition along with 13 pF/meter. Presumably these values result in "reasonable" cathode circuit Q's (2 - 3) with th
- /archives//html/Amps/2006-03/msg00657.html (9,586 bytes)
This search system is powered by
Namazu