[R-390] Another R-390A question

[David Wise]

I wonder if his "bathtub" bypass cap C103 is leaky.
That would limit the maximum resistance to ground.
It's been a while and I'm too lazy to look it up;
isn't it mounted inside the rear skirt?

Dave Wise

> -----Original Message-----
> From: r-390-bounces at mailman.qth.net
> [mailto:r-390-bounces at mailman.qth.net]On Behalf Of David C. Hallam
> Sent: Wednesday, September 13, 2006 6:28 PM
> To: R-390 at mailman. qth. net; Dave Maples
> Subject: RE: [R-390] Another R-390A question
> 
> 
> Dave,
> 
> Remove the jumper from pins 1 & 2 on TB102.  Connect your ohm 
> meter between
> pin 2 and ground.  As you turn the RF gain control, you 
> should read from 0
> to 5K ohm.  I would suspect you have either a short in the 
> pot or a short
> someplace in the circuit.
> 
> David
> KC2JD
> 
> > -----Original Message-----
> > From: r-390-bounces at mailman.qth.net
> > [mailto:r-390-bounces at mailman.qth.net]On Behalf Of Dave Maples
> > Sent: Wednesday, September 13, 2006 7:02 PM
> > To: r-390 at mailman.qth.net
> > Subject: [R-390] Another R-390A question
> >
> >
> > Here's my question:  When I rotate the RF gain counterclockwise
> > on my 390A,
> > there is minimal effect on overall sensitivity (some reduction,
> > but signals
> > are still clearly audible).  Recently I worked on another R-390A