[Heathkit] Any SB-102 Experts out there?

[Kenneth G. Gordon]

On 16 Jun 2006 at 10:35, SBJohnston at aol.com wrote:

> > inadequate BFO injection in the product detector.  There's a
> > suggestion to increase the coupling cap from the carrier oscillator
> > to the detector from 12pF to 100pF, which I will try 
> 
> I did this mod on an HW-101 and ther results were excellent.

Same here. Made world of difference. 

Another useful mod is to remove C-912 a .05 mfd capacitor that is 
connected between the top tap of the audio output transformer and pin 
7 of the audio output tube, V-14B.

The capacitor is easily recognized: it is a large one and is mounted 
UNDER the audio circuit board in the right rear corner of the rig when 
viewed from the top.  

This capacitor provides considerable negative feedback to the audio, 
thus, supposedly, reducing distortion a bit, but at the cost of drastically 
reducing the available audio output level.

Whereas before making this mod, the audio gain pot has to be run 
nearly wide open even for strong signals, afterwards, the AF gain pot 
can be set about 1/3 open for strong signals, and correspondingly 
higher for weak ones.

It makes a BIG difference.

Ken Gordon W7EKB