[Kenwood] Kenwood TS-711A No Rx and No Tx-missing LO injection

Fri Jan 3 21:36:23 EST 2014

I am working on the above TS-711A unit and found no RX or TX. The first
thing I did after getting nothing from the antenna jack was to inject a
146.520 signal into Ra connection on the RF board and still no receive.
I should preface this with that all mode switches seem to be OK, the VFO
encoder tunes smoothly and the display follows. Audio, squelch, and RF gain
functions seem to work.
The next step was to see if I had the LO from the HET-PLL board and while it
was very low on the spectrum analyzer, nowhere near the ,45 v RMS it should
be, something was there. I then injected a 30.265 MHz signal into the IF and
had plenty of signal. Then back to the RF board where I injected a 116.255
MHz signal and used a HT to see if I now had receive which I do, so the
problem likely common to RX and TX is from the HET-PLL string.
>From looking at the block diagram, the PLL unit might or might not be the
problem but next I guess I need to check that the 40.96 MHz and 10.24 MHz
signals are coming into the PLL board from the IF board which is at least
reachable unlike the PLL board. I'm hoping that since the display and
encoder work that it is not the controller board.
Has anybody been down this road before and if so I'm eager to hear what was
discovered.
73,Roger, NJ2R