Bendix KT76C transponder requires major repair: Options?

RST Engineering wrote:
A primary target is one that is not giving any transponder reply; they are
painting you strictly from skin reflection. Why would you think that the
altitude encoder has anything to do with that problem?

A bench check tells you that the box is working. It says nothing about the
antenna or feedline.

Hmmm. I'm not sure if the controller said that I have no "mode C" or if
they were just getting a "primary target." Being under a Mode C Veil,
they deny service just the same. I thought it may be the encoder
because of the significant delay I experience in getting radar contact
with ATC seemed to make sense with others' experiences in their encoder
warm-up times.

Another point of info, when ATC claims that they don't see me, I do
notice that the Reply Light is not flashing. When it does, ATC sees me
a minute or two later after their radar sweeps. So, if it *was* the
encoder and not the transponder, I should still see the Reply Light
flashing, correct??

If so, it sounds like I need to replace the antenna first before
thinking about the transponder.

Marco