This problem may fade away when traditional output meters, hopefully, will
be replaced more and more with pep meters. The problem will remain as long
as some operators want big excursions on their meters and do not know the
difference between pep and average readings. In one the first ARRL SSB
handbooks was an excellent article on this subject, by the way.
To avoid the problem I always try to keep my microphone gain down just below
the point where the ALC starts to show up on the rigs meter in the ALC
position. I will still get maximum pep output but a little less compression
from the ALC. Remember the COLLINS rigs that had dual ALC constants? They
had a little compression from the ALC too.
My guess is, that running your transceiver as an exciter ( output level
adjusted in the menu) or barefoot - the spike will always be there. An
engeneering feedback problem no doubt. Delay in those modern very selective
filters? Or in the multifilters used when hf clipping is used? Or wrong time
constants in the AGC loop? Too much or to little gain in the stages
controlled by the ALC? I am not an specialist but will try to look into my
old SSB handbooks from COLLINS. And I am sure there is somebody om amps who
has dealt with this old problem and knows the answers?
In 1958, my old 75A4 had a similar problem. There was always an overshoot
before the AGC set in on strong signals. For some reasons, there was too
much IF gain, I remember. Even the famous 51S1 has a very bad AGC on SSB:
LA8AK wrote an article how to fix this, by the way.
Hej daa de Hans SM5KI
----------
>Från: "Ian White, G3SEK" <G3SEK@ifwtech.demon.co.uk>
>Till: amps@contesting.com
>Ämne: Re: [AMPS] RE: ALC
>Datum: ons 16 feb 2000 22.00
>
>
>Rich Measures wrote:
>
>>>. Over 24 hours, the gain varies
>>>somewhat and it's asking for trouble to have all the ops keep tweaking the
>>>mic gain.
>>
>>Amen. A high percentage of contest men seem to be infected with terminal
>>''Pump Up the Volume'' disease -- much like CBers.
>>
>In simpler days with simpler rigs, a neat trick was to disconnect the
>front-panel mic gain control and to preset the mic gain internally.
>
>The other essential part of the plot was to pretend that the mic gain
>knob still worked, and to give all the contest ops the usual lecture
>about how it had been carefully adjusted, and they ABSOLUTELY MUST NOT
>touch it. That kept most people fooled for the whole weekend!
>
>73 from Ian G3SEK Editor, 'The VHF/UHF DX Book'
> 'In Practice' columnist for RadCom (RSGB)
> http://www.ifwtech.demon.co.uk/g3sek
>
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