Frank,

The Autek is remarkably close. I have used it to checkout 50 and 25 Ohm loads.
For these two values it is very close. (It is battery level sensitive.)

The couplers are a pair of M-C ZFDC 20-4's.

Dan

Frank's wrote:
"dansawyeror" wrote in message
...

Roy,

No I have not decoupled the feed from the antenna. I will try that
tonight. I have wound a 2:1 balun for testing. (anticipating at least a 25
ohm input impedance)

I have measured the antenna with two different instruments. One is an
Autek analyzer at the antenna, the second is with an 8405a at the end of
100+ feed of cable. They both show the same results.

Thanks - Dan


Dan, I notice the Autek analyzer only measures the magnitude of the
impedance. With any of these lower cost instruments it is impossible to
find any accuracy specifications. The 8405A is an excellent instrument, but
assume you calibrated it -- short/open/load -- at the end of the 100 ft
cable. This calibration should also be carried out on the antenna side of
your isolation transformer when you install it. Curious as to what kind of
directional coupler you are using for HF. I remember using a small HP
coupler for HF, but cannot remember its model number.

Frank