"dansawyeror" wrote in message
. ..
Owen,

Yes, you are right. The single coupler doesn't isolate the channels.
Putting a 10 dbm attenuator between the tee and the coupler changes the 50
Ohm reading. I think a dual directional coupler is required. I will have
to put this on hold until that problem is solved.

Thanks - Dan

Dan

Are you open to trying to assemble something to measure the reflection
coefficient rather than to put the project on hold?
The HP 41952A Transmission/Reflection Test Set uses only one directional
coupler. It uses a power splitter at the input with a pad to level the
outputs from the "Fwd" and "Rev" ports. I can scan some info from the HP
41952 and E-mail them to you if you have interest in building something.
I would think it would be fairly easy to build devices for HF if you
already have a decent directional coupler.

Jerry