Some Interesting Rangemaster Experimentation

I've experimented with the Rangemaster up here in Canada in the past, but have generally found FM to give superior range (we're allowed 4 times the field strength).

I've experimented with the Rangemaster up here in Canada in the past, but have generally found FM to give superior range (we're allowed 4 times the field strength).

I recently moved, and decided to retry some of the experiments. My new location is in the Fraser River Valley, very flat and few obstructions (low buildings, small trees, etc.). I was not able to get the transmitters elevated very far, and tried both my AM and FM setups.

FM was a disappointment. Range was typically 1/4 to 1/2 km at most to a sensitive car receiver, much less than on Bowen Island, which was located on a hillside overlooking the listening area (and therefore offering direct line of sight to the antenna). I didn't hold out much hope for AM, as on Bowen the signal degraded significantly after 1/4 mile, and didn't improve much even with taking liberties with the rules (long ground wire, probably radiating, pumping up the power, etc.) - it was experimentation, after all. I even tried adding multiple radials to little effect.

But imagine my surprise when I was able to easily achieve a 1 mile radius range of a listenable signal, and up to 2 miles in some directions (you could still hear it, but probably wouldn't want to listen to it for very long).

The AM transmitter on Bowen was elevated about 25 feet, with a long ground wire routed to a ground plate buried rather shallowly. Here in the Fraser Valley, I pounded a 4 foot metal mast pipe as deep as I could into the ground, and then attached the transmitter at the top of 2 4 foot metal mast sections inserted into the pounded-in one - the ground wire is attached to the top of the mast by a short length of heavy guage wire. The Rangemaster is properly tuned for output power, checked both manually and with the tuning module (an option on my older unit).

The only reason I can think of for the greatly increased range is the type of ground that is now being used. The house I'm living in is on a floodplain, with moist, rich soil - in other words, it provides an ideal ground. Bowen is basically 3 rocks sticking out of the water, covered in clay and a thin layer of soil (I couldn't pound down a ground rod into the clay, that's why I had to use a ground plate).

My conclusions - all the tweaking you want to do with your transmitter is moot if you don't have a very good ground. I know this has been discussed here in the past, but actually seeing the results is much more effective and dramatic.