Ok, you certainly have some sort of issue with the bias current supply.
It should be a very constant 30mA.
This could definitely cause a pulsing on tx as it wildly changes values.
All of the other info looks good.
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I am not an expert on this circuit, but know that a few others have had issues with it.
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I also remember reading from Jeff W1NC that failures in C504 are not uncommon (soldering, sometimes cracked, etc.)
One user had a broken L501.? And then the broken transistors noted at the above link.
So inspect that part of the circuitry carefully under high magnification for soldering issues or damaged parts.
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Good luck in quickly finding the issue...
Stan KC7XE
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p.s. rev 3 boards are the most recent; they have the LPF capacitors preinstalled.
