In message , Peter
writes
Hi all.

This may seem like a fairly basic question. But here we go!

I want to performance test a 436MHz high gain antenna. My plan is to
construct a simple dipole with a 1:1 balun for 436MHz as a reference antenna
and construct another dipole with a 1:1 balun to receive the test signal,
measure it with a diode detector and a milli-amp meter (field strength
meter) at the shack. Do the calculation and have the antenna gain.
This seems to me to be fairly straight forward, but has anyone carried out
similar measurements and concur with the approach or are there are there
traps and pit falls that I need to be aware of. Or is their simply a better
way?

I've done it on 1296MHz in a similar way. However I borrowed a
calibrated step attenuator and took the difference in readings between
the reference dipole and the antenna under test as the gain for the same
detector reading to avoid nonlinearities. You can also measure antenna
gain using sun noise on 70cm, but that's a bit trickier.

Brian GM4DIJ


--
Brian Howie