This is a very hard radio to work on, as you can not easily get to the PA board the way it is soldered into the pa driver.
I would remove the PA board, replace L305, for starters while it is out you can inspect the components one by one.
This unit does not lend itself to test and measurements, as all you can do is prod the rear.
All HF PA stages have an impedance in the mOhms .1 .2 ohms as thet6drsw 20A, the out put transformer has to match .1 of an ohm to 50, so it needs to step up the voltage.
KR
Andrew
I have a wiring unit, I can make some measurements for you
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On 26 Jan 2025, 01:32, at 01:32, "Tommy Wooten via groups.io" <kf4rwg@...> wrote:
Bob, Thanks for the encouragement
I have considered all of the suggestions for troubleshooting the
problem I
have with the IC7000. I have tried to trace the HF RF path with an
oscilloscope from where the signal comes through the cable from the
main
board to the PA board. I have traced the signal and inspect all
components
through to the output at ant1. The signal seems to loose its punch
where
the PA FETs combine into the L305 transformer. The bias setting of the
PA
FETs seem to be correct. After the signal reaches the rx/rx relay it
passes through the selected HPF where it reaches ant1. The resulting
signal is only a few milliwatts. I have tried to keep the setting in
SSB
and I see modulation when speaking into the microphone.
I know it is difficult to troubleshoot the issue remotely but I
appreciate
any and all ideas.
Thanks
Tommy. KF4RWG
On Sat, Jan 25, 2025 at 6:31?PM Bob via groups.io <W4JFABob=
[email protected]> wrote:
Well this is #30 then. That's OK because when the rest of us have
this
problem we'll appreciate every one of these replies.
Keep on writin' you guys.
Bob W4JFA
On Thu, Jan 23, 2025 at 4:40?PM Geoff via groups.io <vk3zgw=
[email protected]> wrote:
Forgive me if this has been mentioned before but as this is the 29th
reply I haven't gone back and read everything.
I always go first to where the effect of a fault is obvious without
any
ambiguity, in this case the rf output ie Ant 1 connector, working
back to
eliminate ALL the stages involved, including in this case the SO32
jack.
Good luck.
Geoff
VK3ZGW
Andrew Lenton