Hi Bill,
Let's start with some guidelines on posting for help.? This list server covers many radios and conditions¡ªeverything from a home brew, one-of-a-kind, to popular radios from companies like HFSignals and AmateurRadioKits.? To get help, we need to know the radio and the version that has the problem.? An example might be an uBitx v6 from HFSignals.? Also, are there any modifications to the radio, like AGC added or a new screen?
It also helps to list the power supply and antenna used.? This can help as the problem is often caused by how the radio is installed or used.
The last area that helps is to describe what, if any, testing you have done.? This will often lead to requests for test equipment that you might have to help responses target tests you can do.? An example would be a spurious signal issue that may best be found with a spectrum analyzer you may or may not have.? If that is unavailable, there could be alternate ways to test with another receiver or RTL-SDR dongle.? You did provide some of this data with the power supply voltage measurements.
So to get started, please let us know the radio that is having the problem.??
Has the radio ever worked correctly?
Have you measured the current drawn by the radio on both transmit and receive?
What power supply are you using, and what is the current capability of the supply?
Do you have a 50-ohm dummy load rated for the radio's power output?
These are questions that I would need to start to help find the issue.
Taking a stab in the dark without the above information, I think that two conditions could cause the issue you describe for most of the radios this group covers.? The number one cause is RF feedback in your shack.? This can be verified by transmitting into a dummy load.? The other common cause is a power supply that can not provide the current required.??
73
Evan
AC9TU
