The Best of Both Worlds?
Posted on October 9, 2005
12vman writes I have a thought.. “Could a low powered FM xmtr (Part-15) be used to transmit audio to a Part-15 AM xmtr?”
12vman writes I have a thought.. “Could a low powered FM xmtr (Part-15) be used to transmit audio to a Part-15 AM xmtr?”
I mounted the SSTRAN and an F.M. pocket radio (mono) in a weatherproof box at the base of the antenna. I use a Velleman kit F.M. xmtr to get sound to the SSTRAN. I had the most trouble with getting the Velleman to sound good. After that, everything was fine..
I find that the A.M. doesn’t bother the F.M. at all! Actually, the highs are better than going through cables. Much cleaner! The bass response is great! Holds togather very well! The compression on the SSTRAN is touchy but once it’s set, it almost sounds as good as the F.M. direct. I could adjust the antenna better without the audio cables running up there. I got a better (higher) voltage easier without them. Everytime I connected the audio cables to the SSTRAN with the V.O.M. on the test points, the voltage would drop 2 volts. Now the only cable going up there is power. I can get a great peak as high as 15 volts. I couldn’t do that before. Also I believe that some of the R.F. from the SSTRAN was going down the audio lines to my mixer making it sound somewhat “Softer” than it is now. Much less background noise also..
I operate the SSTRAN and the pocket radio from a 24 volt D.C. supply. I decided to convert the 12 volts to 24 volts in the house and send it up to the top because of less loses through the wiring. I have around 26 V.D.C. at the xmtr and connected that directly to the xmtr. I used a 7805 regulator to operate the pocket radio. I contacted SSTRAN about this and Phil said it would be ok but approaching the high limit of the 15 volt on board regulator. I let it run for 3 days constant with no issues..
Leave a Reply