[Elecraft] Alignment of VCO - Problem

[David C Dawson]

THANKS DON! The problem is solved, and good news - Q17 is fine.

When I got your email, I turned on the rig and put the frequency probe
on TP1. This time it measured a frequency and a correct one at that.

I thought - Before it didn't work. Now it does. Hmmmm...Hmmmm... Aha!
loose connection! So I touched Q17 and off it went, I found a poor
solder joint that my (non) eagle eye missed.

Talk about bone headed screwdriver experts, eh?

On Wed, Nov 15, 2006 at 08:03:06AM -0500, Don Wilhelm wrote:
> David,
> 
> Reviewing your voltage readings with my 2nd cup of tea this morning, I find
> Q17 might be giving you a problem.  Temporarily short the drain of Q17 to
> ground and see if your VFO starts oscillating.
> 
> If it does, then Q17 may have been zapped during handling and installation -
> those 2N7000s are static sensitive.
> 
> 73,
> Don W3FPR
> 
> > -----Original Message-----
> > From: elecraft-bounces at mailman.qth.net
> > [mailto:elecraft-bounces at mailman.qth.net]On Behalf Of David C Dawson
> > Sent: Wednesday, November 15, 2006 3:07 AM
> > To: elecraft at mailman.qth.net
> > Subject: Re: [Elecraft] Alignment of VCO - Problem
> >
> >
> > Double-checking DC voltage measurements on 3 transistors.
> >
> > Item Measured  Chart
> > Q18
> > ---
> > G:   0.00      -1.0     !!
> > S:   1.97 **    2to3
> > D:   7.97       6.3     !
> >
> > Q17
> > ---
> > G:   2.16 *     2.2
> > S:   0.00       0.0
> > D:   1.97 **    2to3
> >
> > Q16
> > ---
> > E:   0.00      0.0
> > B:   0.55      0.6
> > C:   2.16 *    2.2
> > --
> > David Dawson
> >
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> 

-- 
David Dawson

A strong conviction that something must be done is the parent of many
bad measures.
                -- Daniel Webster