"Tom Horne" wrote in message
news:j1aZi.80$Y32.72@trnddc04...
Hal Rosser wrote:
"Hal Rosser" wrote in message
...
"Tom Horne" wrote in message
news:Md4Zi.36$WN2.29@trnddc08...
Is it possible to ask questions here without triggering an arcane
debate about competing views of theory. I'm about to find out. I
asked earlier in another thread what measuring instruments I would need
to have the use of in order to compare the effective radiated power of
different antennas. As near as I can tell there was no answer.
Tom Horne, W3TDH
A Field strength meter can be used to compare relative output of
antennas.

Well, in addition to a field strength meter, some low low power source
hooked onto to your antenna may help so you don't have to drive all over
the country side. I used an MFJ antenna Analyzer, some string, and a tape
measure, to 'map-out' on a graph locations of equal field strength.
Just have to watch out for your body affecting the signal pattern.


Please guys
Without going to war with each other over the answer and leaving me not
knowing who to believe, is an MFJ analyzer a good choice in the under five
hundred dollar range? Would using one of the one watt HTs do for a signal
source or is that still to high.
--
Tom Horne

Tom,

A one watt HT will do fine, but the signal will still be too strong close in
to work with. You need to get the power down to perhaps one milliwatt or
less to plot the antenna pattern in a field or car park. You can make up an
attenuator to reduce the power from the HT. Just making up a patch lead
between the HT and the antenna with a 50 ohm, 1 watt resistor shorting the
core and outer will probably reduce the signal to something you can work
with while still giving the transmitter a load to work into. (You can make
up exactly 50 ohms using two 100 ohm, 1/2 watt resistors). Or make up a
simple single transistor 'bug' transmitter from a handful of components.
Plenty of designs available through Google No need to spend more than a
couple of dollars. The 9v battery is likely to be the most expensive bit.

Mike G0ULI