[TenTec] Omni D final wiring

[Shawn Upton]

Ack, apologies, not sure what happened to my formatting.
Yeepers, haven't worked on this in a while...  Background: Omni D, not a later C.  Last I fired this up, no RF output but the ammeter on the power supply registered 20A.  So I pulled the main feed to the PA and put in an ammeter into the smaller red lead, as per the manual.  Current went first to >400mA (supposed to be 4 to 8 milliamps) before settling down to 10mA.  During this time smoke decided to roll out.  Termination of testing.
Pulled the PA and it looks like R8 smoked.  R8 is 3.3 ohm feeding Q4.  But Q3/Q4 had no power so not sure why it would smoke.  The white/gray wire for bias is after this 3.3ohm so I'm a bit surprised.

I checked driver and final transistors, without removing them; the final shows typical diode connections.  The driver shows base to collector ok, but the base to emitter is shunted by 32 ohm (the bias adjust pot apparently).  Have not pulled transistors to test further.

Any idea while R8 would smoke?

The white/gray wire bias, hmm, something wrong there: With no PA installed I measured 4.5V and rising with the radio in TX.  Ah, stupid me, with the PA removed the bias diode is missing.  Clipped in a 1N4004 and I get 0.64V for bias to the PA.

shawn kb1ckt