SBE Console V woes

[guitar_199]

Following the advice from Rick in another thread, I was able to track down a bad PCB feedthrough such that the last three stages were not getting a switched TX voltage. Well, I was able to fix that and now, my handy DMM shows that the voltages are okay in the transmit section now and, per the Sams Photofact, the bias voltages around those transistors look good as well.

Problem now, when I key, something comes out but not much. I have it hooked to an SWR meter with a dummy load (50 ohm/10 watt) on the other end of the meter. On the 10 watt range you can see the meter move, but not by much.........maybe 1/4 watt or so. If I put the meter on SWR and CAL, and adjust the CAL knob to the top the meter deflects really good, but that doesn't mean much.

Now, here is the theory I am working on:

All receive functions are working..... AM SSB..... all of them. This leads me to believe that the oscillators are working since I THINK all of the oscillators are common to both RCV and XMT.

I am trying to locate anyone that I know that has a scope with enough bandwidth to use to look at the various stages to see where things drop off.

If reading this gives anyone any ideas or tips for troubleshooting this I would love to hear them.... thanks!!!

[Rick]

It sounds like you have a bad Driver or Final.
What are the voltages on the Base and Collector of the Driver and Final, with the radio key-up on AM?

You do not need a scope, but RF Probe would be very helpfully, there are very easy to make, check out the following www.io.com/~n5fc/rfprobe2.htm www.flashwebhost.com/circuit/rfprobe.php
http://www.njqrp.org/mbrproj/rf_probe.html
http://sound.westhost.com/project74.htm