Total posts : 45366
Thought you would like to see the current prototype transmitter.
http://www.talkingsign.com/images/prototx.jpg
It has built-in compression/limiting, auto power adjust, microprocessor auto servo tuning (so you don’t have to be at the top of a pole to tune it). It’s lightweight and rugged. The only problem I might have is that auto tuning of an AM low power transmitter has been patented by the ACTradio guys (I found that out after the fact). I have changed it to a second version that has a manual tuning arrangement: it has 2 buttons to tune the loading coil together with a digital signal strength readout. Remote tuning is very nice to have. The advantage of the second method compared to the first is that you can monitor the signal strength.
If I leave out the servo tuning I could reduce cost, but then you have to be at the top of the pole. The arrangement I have now is a 10ft 1.5″ dia. pole that is hinged at the bottom. I can swing it down, work on the transmitter and then swing it back up again. This is on my kids old swing set – imagine if it was on the chimney :). The range at the moment is 1 -2 miles using a single 5ft ground rod. I can’t pound the rod in any further because my clay is so hard.
Gerry
