Mike,

Here is something to watch out for. I tried to measure the pattern for a 432
antenna. I had coax going from the shack to the transmit antenna, and
another coax going to the receive antenna. I measured complete garbage for
the pattern, until I realized that the receive antenna was picking up a
signal any time it was aimed at the transmitter COAX. I fixed the problem by
moving the signal source to be collocated with the transmit antenna.

One way to get accurate gain readings is to use the receive S meter and a
calibrated attenuator. For instance, if with the reference antenna you need
15db of attenuation to get an S9 reading, and with the target antenna you
need 27 db of attenuation to get S9, the gain of the target antenna is 27 -
15 = 12 db. Some S meters are more accurate for low signals; so, you might
want to use something like S3 for a reference.

Tam/WB2TT
"Peter" wrote in message
...
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?


Cheers

--
Peter Miles VK3YSF
Melbourne, Australia