I was wondering if anyone has experience using the Greek made ASMAX-1 Part 15 AM Stereo transmitter for their Part 15 broadcast station, and what their experience has been with audio quality and signal range compared to other transmitters. I would be especially interested if anyone has adapted the transmitter for use with the SSTran base loaded antenna system. The US version of the ASMAX-1 has an RCA plug output to the antenna, just like the SSTran, but I don't know if they have the same output impedance. (The ASMAX-1 Euro version's output is 50 ohms. I don't know what the US version is, or that of the SSTran.)
I would like to upgrade the operation of one of my stations to AM Stereo someday, but I want to keep my dependable SSTran antenna and ground system. Even with the SSTran, you have to disable a couple of the internal coils in order to use their own antenna plans. I imagine it would be the same with the ASMAX-1?
The antenna described for use with the SSTRAN should perfom well with a transmitter with a 50 ohm output Z but it would require changing the tuning. The reason for this is that the antenna when used with the SSTRAN is not tuned to resonance but is a bit off resonance. This, coupled with the tuning capacitor in the transmitter transforms the low resistance of the radiator and ground system up to about 800 ohms which the SSTRAN sees and requires. PhilB gave a great explanation of this on this board some time ago and I will try to find the post and link it here when I get a chance.
A good part 15 antenna and ground such as the SSTRAN recommended antenna would, properly tuned, provide a resistive load in the range of 20 to 100 ohms resistive which would work well with a 50 ohm output transmitter.
Neil
OK, I found the links I was referencing. They are:
http://part15.us/node/883#comment-4258
And the entire thread is:
Lots of stuff to read on the topic in this thread.
Neil