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Old December 20th 10, 02:37 AM posted to rec.radio.amateur.antenna
John - KD5YI[_3_] John - KD5YI[_3_] is offline
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First recorded activity by RadioBanter: Dec 2010
Posts: 54
Default Antenna measurements with 8405

Hi -

My frequency of interest is about 434 MHz. I have the following equipment:

HP 8405A vector voltmeter
HP Accessory kit for the above
HP App note AN77-3 (compliments of Wes Stewart)
Fluke 6061A signal generator
Mini-Circuits 40-1000 MHz dual directional coupler.

I'm not sure the info above is really required for this question, but I
thought it couldn't hurt.

The question is: I use about an 8-foot piece of coax to go from the
output of the directional coupler to the antenna so as to reduce my body
and instrument influence. When I follow AN77-3, I do so at the antenna
end of the coax. That is, I set up the 8405A with a short at the end of
the coax. I figure the coax is only about .8 dB of loss. Is this a valid
way of doing the measurement, or must I set up the 8405 with a short on
the output of the coupler and characterize the coax and then calculate
the answer?

Thanks,
John