My old Warrior's parasitic supressors need to be changed and I need to know what the optimum value of inducatance is for the supressor. The carbon type resistors are showing their age as well. Not on
// Suppressor resistors (Rsup) typically increase in resistance during an intermittent parasitic oscillation condition. Thus, it seems likely that you had one or more. For instance, I have seen Rsup
Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK)
Date: Mon, 3 Sep 2001 14:37:16 +0100
"So-called" is correct. According to the schematics, it consisted of a feedback capacitor from the output end of the pi-tank, back to the cathode. This will produce feedback of variable amplitude and
That is NOT correct Ian. Bad enough that Rich says things without being fully aware what is going on! The feedback in the Warrior is from the anode, through a capacitor, through a phase inverting tr
Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK)
Date: Mon, 3 Sep 2001 17:36:45 +0100
Sorry, it appears I was confusing the Warrior with another amp... maybe the Yaesu, though I don't recall ever seen that schematic. I agree that a phase inverting transformer, coupled as you describe,
// The latter, Ian cheers - R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures. end -- FAQ on WWW: http://www.contesting.com/FAQ/amps Submissions: amps@contesting.com Administrative requests:
// Rich is fully aware that the 811's filament is the "cathode" (Ian). // The Warrior and the Gonset 4, 811A amplifier used the same neutralization scheem. // However, there must be a frequency-depe
Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK)
Date: Mon, 3 Sep 2001 22:41:18 +0100
Just a plain fact. The circuits are different. 73 from Ian G3SEK Editor, 'The VHF/UHF DX Book' 'In Practice' columnist for RadCom (RSGB) http://www.ifwtech.com/g3sek -- FAQ on WWW: http://www.contest
Hi Ian, I'm not sure if all runs of the FL2100 do this, but the FL2100 I looked at takes a sample of RF after the pi-network and feeds it back to the input. Of course in that system the operating Q o
// Is the theory of operation different? - R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures. end -- FAQ on WWW: http://www.contesting.com/FAQ/amps Submissions: amps@contesting.com Administr
// The sticky wicket is not that the Warrior oscillates on the operating frequency, it oscillates above the 811A's VHF grid resonance. This is seemingly why subsequent Heath models abandoned so call
Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK)
Date: Tue, 4 Sep 2001 07:38:48 +0100
Basic electronic theory remains the same, but the circuit is different so the ways they operate are too. 73 from Ian G3SEK Editor, 'The VHF/UHF DX Book' 'In Practice' columnist for RadCom (RSGB) http
// Is neutralization at the operating frequency. or at the anode-resonance frequency (c. 80MHz)? - R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures. end -- FAQ on WWW: http://www.contesting
Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK)
Date: Tue, 4 Sep 2001 14:08:19 +0100
We were just told that neutralization is carried out at the high end of the operating range. It's just another kind of balanced bridge, so it should improve stability at the VHF resonant frequency to
Rich: // I do not accept everything I am told. Some men tell the truth but other men have less couth. // Why and how? Below the grid-resonance frequency, regeneration should not be possible since th
I'd make sure I had a neutralizing system, and use a suppressor like the Ameritron AL811H uses if I was refurbishing a Warrior. There are two distinctly different stability problems with tubes like
// I have never heard of a grounded-grid 811A or 572B oscillating at HF. - R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures. end -- FAQ on WWW: http://www.contesting.com/FAQ/amps Submission