Re: test points


Evan Hand
 

Michel,
The short answer is no, there is not a set of oscilloscope or signal level traces for the TPs on the schematic.  You should note that the input signal levels are very low on the receiver side, on the order of microvolts, so most oscilloscopes will not be able to measure them.  Some of us have captured traces for the driver and PA side of the transmitter, however, those were for v5 or earlier.

The most effective troubleshooting seems to be with signal tracing.  This works for the CW transmitter starting with the Clock2 LO that generates the CW signal at TP12 and going through TP2, TP1, and so on to the drivers and PA to the antenna.  Once past the base of Q90, starting with the collector, the signal is strong enough to capture the waveforms.  OTE, they are not pretty, as the rig does rely on filtering to smooth out the signals before applying to the antenna.  You just need to know that the frequency is correct and that the signal is increasing as you move closer to the antenna.  If you get this section to work on CW, then the power side of the RF is done.  

As far as the receiver signals,  I have not done that tracing.  Seems like the most successful method that I have seen os to inject a low-level signal that matches each expected frequency starting with the audio section and working towards the antenna again.  When you lose the signal, you have found the stage that has the issue.

When you combine the static voltage tests, I do not know of a problem that could not be solved.

Above are what I have experienced or read.  I may be in error, so all should verify.
73
Evan
AC9TU

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