[ARC5] "ARC-5" Receivers and "Q" multipliers

[Peter Eijlander (PA0PJE)]

I have made a simple Q multiplier in a WS19 with a subminiature 
twin-triode 6021WA, which I got once from someone who worked in radar 
maintenance. It laid unused for years 'till I found a simple circuit in 
the Radio Communications Handbook of the RSGB. I swapped the B-set 
tuning cap for a beautiful Bourns WW-pot from the same source. Works 
very smooth, can be set very close to oscillation and enhances 
selectivity much.

I made a scan of the page of the book. If you are interested I can send 
the .pdf. I don't know how easy or difficult it is to get this 6021 
miniature tube.

73,
Peter - PA0PJE

Op 2015-08-11 17:17 schreef Phillip Carpenter:
>> There was an article in QST probably around the summer of 1961 for a Command Set
>> >>receiver Q-multiplier.  Used only a pot and a gimmick.  Worked pretty well.
>> >>Took some ingenuity to get the pot shoehorned into the plug-in front box,
>> >>though.
>>
>>I've used that one: it works fairly well in the 6 - 9.1 MHz receivers, not so well
>>in the 3 - 6, and not worth doing in the MF jobs. What it actually does is to
>>make the first IF regenerative. It works pretty well when the signals are weak,
>>but as the signal levels rise, it gets less effective.
>>
>>Even so, a REAL "Q" multiplier works a lot better.