RE: Alignment and Test Part 2

Posted by Don Wilhelm-3 on Apr 02, 2005; 6:51pm
URL: http://elecraft.85.s1.nabble.com/Alignment-and-Test-Part-2-tp376519p376522.html

Dave,

You did anticipate my next question, and now I believe I can say that Q3 has
been somehow zapped since it appears to be conduction with a very low
voltage on the gate.  Replace it with the 2N7000 that remains unmounted in
your K2 parts and request a replacement from Elecraft so you can fill the
holes at Q10 on the RF board later.  I beileve that will fix your problem.

73,
Don W3FPR

> -----Original Message-----
>
> Thanks for the reply, Don.
>
> D6 and D7 are oriented properly.
>
> I am measuring 7.94 volts on the collector of Q1 and 7.15 volts on the
> collector of Q2.
>
> Anticipating your next question, on Q3 I am measuring:  S=0
> G=47mV D=51 mV.
> D should be 8 volts according to the manual.
>
> Tnx & 73,
> Dave
> N7AF
>
> ----- Original Message -----
> From: "W3FPR - Don Wilhelm" <[hidden email]>
> To: "Cyberider" <[hidden email]>; <[hidden email]>
> Sent: Saturday, April 02, 2005 10:49 AM
> Subject: RE: [Elecraft] Alignment and Test Part 2
>
>
> > Dave,
> >
> > It would appear from those readings that either you have D6 or D7
> installed
> > backwards or that both the 8R and 8T voltage lines are active, and they
> > should be mutually exclusive.
> >
> > First check the diode orientation against the Parts Placement Diagram in
> the
> > rear of your manual, and if these are correct, measure the sources of 8R
> and
> > 8T at the collectors of Q1 (8T) and Q2 (8R) on the Control
> Board.  If both
> > are near 8 volts at the same time, you have a problem with the
> controlling
> > circuit in the base of Q1.
> >
> > Let us know what you find and we can proceed from there.
> >
> > 73,
> > Don W3FPR
> >
> > > -----Original Message-----
> > >
> > > I am not getting any significant signal input from the antenna
> > > and the loss seems to be at D6.  In trying to determine whether
> > > D6 is at fault, I'm measuring 7.13 volts on the anode and 7.31
> > > volts on the cathode.  The manual indicates they should be 8.0
> > > and 7.5 volts respectively.  On D7, I'm measuring 7.94 volts on
> > > the anode and 7.31 volts on the cathode.  The manual indicates
> > > 0.0 (error?) and 7.5 volts respectively.  Before I blame D6 for
> > > the loss of signal, is there something else going on here that
> > > may be causing the problem?
> > >
> > > Thanks,
> > > Dave
> > > N7AF
> > >
> >
> >
>
>

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