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Old 7th Mar 2021, 12:50 pm   #15
David Simpson
Nonode
 
Join Date: Mar 2008
Location: Aberdeen, UK.
Posts: 2,838
Default Re: Noise in receivers

Ian, from your reminiscences of military aircraft equipment back in the 60's(working in a wireless bay ?), I'll stab a guess that you've done an RAAF, or RAF "Fitters Course" ? Just like me. Get out your old training notes & have a shufti - its all explained. "Aircraft VHF Receivers" eh ? I'll again stab - at the 1985 series 10 channel VHF transceivers. Or possibly - ARC52. AP's for both can be accessed via the VMARS huge online archive, or bought from Birketts in Lincoln over here. Again, these "2nd line/3rd line AP's fully explain the noise reduction circuitry. Stretching my memory to the limit - there was a whole chapter in the ARC52's AP on their efficient "squelching" circuitry. ( Set at 5uV, using a CT394B) - I've done quite a few back in those far off days.
The whole plethora of "Radio noise" sources/avoidance would take up reams of Forum thread pages. (More than phooked AVO VCM's of late, eh).

Regards, David
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