[Drake] T-4XC low output

[K4GM- George]

Thanks to all for suggestions and info.  I'll follow the suggestions 
and share the results.

K4GM- George

At 09:21 PM 9/12/2005, you wrote:
>It sounds like you may have a PTO output level issue George.
>
>If you have access to a good scope or spectrum analyzer, compare PTO outputs
>between the R4C and T4XC. Its easy to get to the outputs (under the set)
>
>If you don't have access to the test equipment, swapping the oscillators
>between the transmitter and receiver isn't terribly difficult.
>
>Good luck!
>
>Paul
>
> > -----Original Message-----
> > From: drake-bounces at mailman.qth.net
> > [mailto:drake-bounces at mailman.qth.net]On Behalf Of K4GM- George
> > Sent: Sunday, September 11, 2005 7:47 PM
> > To: Drake at mailman.qth.net
> > Subject: [Drake] T-4XC low output
> >
> >
> > Here's my problem for which I ask your advice.
> >
> > I can't get more than ten watts out of my T-4XC when using the
> > internal PTO.  It is drawing at most 120 ma.  Increasing the loading
> > won't help.   When I have it connected to the R-4C I can hear the
> > SPOT signal at S3 but it was S9 when the rig was working
> > correctly.   I cannot hear the SPOT on my Icom located 3 feet
> > away.  If I place it in Tune or CW I can hear the signal at S9 on my
> > Icom.  The T-4XC is connected to a Dummy load for these tests.
> >
> > All voltages are within 10-15% on V3, V4 and V8  (mixer and driver)
> > except that there is zero voltage on the grid of the mixer (should be
> > .3v).  Resistances from tube socket pins are as in the manual except
> > that the grid pin on the mixer reads about 950K while the manual says
> > 450K.  I have checked the resistors individually which feed voltage
> > to the mixer and they are fine.
> >
> > If I set the bandswitch to 20m and peak the RF TUNE in the 40 m
> > range(as I have done more than once by accident when switching from
> > 40 to 20) the radio will tune to an output of 125 watts like it used to.
> >
> > Any suggestions would be appreciated.  Also, does anyone know where I
> > can find what the RF voltages should be at various stages in the xmtr??
> >
> > Please help.   I have the excellent CD repair guide from K4OAH so am
> > ready to tackle this one but seem to be going in circles.  This xmtr
> > was my best one until it went south.
> >
> > And, finally,  if I switch to the R-4C for frequency control the
> > T-4XC works perfectly!!!
> >
> > K4GM - George
> >
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