Re: No output QCX 40 output drains show 1.6 watts in receive


Alan G4ZFQ
 

CLK 1
goes from 1.7 on receive to zero on transmit.
George,

That's enough to tell it is going to TX mode.
You need to remove IC3 and test the voltages on it's pin 4 and pin 12 pads, RX and TX modes.

IC3 can be removed by carefully cutting each leg then removing each leg separately.

73 Alan G4ZFQ
IC3 looks as if it has failed. If pins 1,2 are high then pin 1
should be
low.
What are the voltages on Q1,2,3?
Also it looks as if IC1 is not sending a TX signal to IC3 and
that Clk2
is not turned on for TX.
Is it going into TX mode? Does IC1 pin 3 go low when the "Key"
switch is
pressed?

Join QRPLabs@groups.io to automatically receive all group messages.