Topband: Measuring field strength

[Tom Rauch]

> At any rate, it seems like I can do faster A/B testing of 
> added
> radials with a reciprocal method rather than having to key 
> the station
> transmitter and run out to the field strength meter each 
> time.  Are
> there any caveats to this method other than making sure 
> that the RX is
> terminated properly?

I actually use a "pinger" to measure my receiving antennas. 
It is a battery powered oscillator using a cheap 1843 kHz 
time base crystal that drives a six-foot whip.  A 555 timer 
pulses the source off and on to increase battery life.

The only catch is I have to make sure the source doesn't 
couple to any conductors that might re-radiate close to or 
in a different direction from the antenna being tested. In 
other words I place the pinger  in an area clear of other 
conductors. The same caution is true if we were measuring 
instead of generating, of course.

One wavelength distance is plenty in your case, although 
some of my large receiving antennas don't have the pattern 
fully formed for several wavelengths.

73 Tom