[amsat-bb] Mirage T-injector Problem

[Richard Lawn]

Finally did diagnose the problem as a 2.5 volt drop under load at the
T-injector. With the output on the bench showing barely 11v under load this
brought the voltage down to the bottom end of what the ARR preamp needs to
function. I suspect that under load at the end of 60' of coax it was even
lower than 11v. Jay at ARR was very helpful in working with me to get to
the bottom of the mystery as I had the same problem with two different
vintage Mirage T-injectors and both worked fine with Mirage and Icom
preamps, so it was quite a mystery. We determined that if you eliminate the
10ohm resister off the injector pwr switch and replace it with a jumper the
problem is solved. Of course I could have used a separate line to remotely
power the ARR preamps but that was going to be very difficult at my QTH.
Problem it looks like is solved. And thanks to everyone for your useful
suggestions and questions that led to solving the mystery.

73
Rick, W2JAZ