Total posts : 45366
I built up the AM 100 without the modulation boost in place, At the time discussions were about the distortion it added, and on top of it my knowledge (at the time) of loading coils and proper antenna really wasent that great, so the performance I was getting was like any AM 100 MW transmitter with a ten foot piece of wire without a loading coil, which is in most cases gives about five feet of range.. anyway I havent fired up the AM 100 for some years, I went FM years ago, but now back into AM and know the loading coil is very important and they are easy to build, so am anxious to try the AM 100 again to see what it will do. Of course this means taking it out of that nice box and unsoldering some wires, I hate to burn up someting in the process to convert to positive modulation to get the 300%.
Has anyone used one of these transmitters with a proper loading coil running the transmitter in the 300% mode?
Back then, I built the transmitter and got very short range with it because of a poor antenna system I was using, and like ohters who tired AM, I got discouraged and gave up on it.
I do remember the crystal clear sound of the transmitter. Tuning it up with a 50 ohm dummy load using a scope, all the wave forms looked good and the power checked out where it was supposed to be, Everything was correct, but the problem was the piece of wire comming off the antenna jack. Just a piece of wire and no loading coil didnt do the transmitter justice, years later I figured it all out how to do the antenna system correctly.
By the way, can anyone look at the schmatic of the push pull power amp on the AM 100 and tell me how to convert just that stage to 12-15 volts ( non split power supply) if I made just the amp part? Right now the amp is made for a split 15 volt + and 15 Volt – power supply, with ground ( common )through the bias network it looks like. I would like to take the power amp section and make a small stand alone amp for other LPAM projects, it looks like the parts and circuit shoud be good for at least 500MW ( for a lab amp of course). Ernie liked his split power supplies.