Before you start ripping apart your rig and blaming the microcontroller, are you absolutely sure this is not AC ripple in the power supply??? ?Receive puts no significant load on a supply, but transmit does, and if the main filter cap in the supply is not up to the task then ripple will get past the challenged voltage regulator. A digital meter won’t show the ripple on the power supply, but an oscilloscope would.
Another idea is that RF is getting back into the rig and disturbing circuits such that buzz is produced. That’s where my money is.
I used to teach system repair. New students too often blamed the big chips they didn’t understand yet, instead of considering the many other simple possibilities. Another useless approach too often employed was the random measurement of voltage around the circuit, presumably in the hope that something might appear to show them where the fault lay. Often the probe would slip, there would be sparks, and now the circuit really did have a major fault. Measurements are to confirm or falsify a suspicion based upon an understanding of how a circuit might fail and produce the observed symptoms. It requires logic.
In this case you need to think “How does this circuit function and what would cause a buzz in this circuit during transmit?” ?The microcontroller is way down the list of suspects.
toggle quoted message
Show quoted text
On Feb 23, 2025, at 21:24, Tech Guy via groups.io <tech48055@...> wrote:
?
Thanks for the tip but I think the microcontroller is damaged. I guess I will order one. Very erratic. Voltage is ok. When booted it emits a tone constantly when keyed. Rebooting is the only way to stop it. Then it may work. It ?stops responding to the paddle input after a few characters. I am going to look a little more. I think I may have a spare microcontroller. It would be any easy test to swap it.
73s John N4HNO
