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

[Phillip Carpenter]

That would be Lew McCoy's "A Poor Man's Q Multiplier", QST March 1960, pp. 46-47.

Mike, WU2D tested that circuit on a BC-453 and it worked good so long as the caps around the IFs are not leaky, otherwise it becomes unstable and goes into oscillation.

73s,

Phillip W4RTX

Sent from my iPhone

> On Aug 11, 2015, at 10:29 AM, Kenneth G. Gordon <kgordon2006 at frontier.com> wrote:
> 
>> On 11 Aug 2015 at 1:52, WA5CAB at cs.com wrote:
>> 
>> 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.
> 
> Mike Murphy WU2D's addition of a crystal-filter to the 6 - 9.1 MHz jobs 
> REALLY makes a huge difference. He simply uses the first IF coil and a 
> crystal to do that.
> 
> Ken W7EKB
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