Home › Forums › temp › What AM equipment are you using, and what grounding system? › Talking House Range
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I have a Talking House transmitter and it meets or slightly exceeds the allowed 100 mW input power as tested on a commercial station monitor into a 50 ohm load. So as far as the carrier field strength, it should be very close to any other Part 15 compliant transmitter designed to work into a 50 ohm load.
Where it may be lacking is in the modulation, where the audio power is. So even though the dead carrier may be the same or better, the audio may sound weaker resulting in reduced “useable” range.
My Talking House transmitter was connected to a roof-top antenna. The antenna is a 3 meter radiator connected to an “L” network (lossy) tuner at the base of the antenna. My usable range was about a 4/10 mile radius and could be heard in isolated spots over a mile away.
Recently I did a little story about an antenna project. This new antenna, ground mounted, made quite a difference almost doubling the range.
My point? Tinker, tinker, tinker with the antennas as that’s your best point to improve your signal (all other things staying reasonably legal.) You mentioned using an 8 foot ground rod. For my ground mounted antenna my experience has been that a few wire radials on the ground work better. This was observed using both a field strength meter and driving away from the antenna listening on the car radio.
Since probably 99% of us don’t have the money or space to put 120 radials, 1/4 wavelength long under our antenna, do put whatever you can. Just try to make the radials equal and opposite each other, i.e. 4 radials 90 degrees apart, 6 radials 60 degrees apart, etc. Make them at least as long as the antenna, longer better.
Take a look at this POWERPLANE GROUND SYSTEM marketed by ISS. The drawing gives an excellent description of a ground plane system you could build. I’m not endorsing their products but I was recently involved with installing one of their low power AM stations for our city. I operate and maintain the system and with 2.5 watts into what looks like a Part 15 compliant antenna on the roof, the station can be heard within a 5 mile radius with no problem. I lowered the output power to 100 mW and could still hear it well enough within a 3 mile radius. That says alot about the antenna system.