At 06:05 PM 9/18/2007, you wrote:
Hamtronics and they are still in business and do offer a wide range of inexpensive preamps. See http://www.hamtronics.com/lnk.htm.
I have a couple of concerns about those preamps. They are probably fine for portable/HT operation, but they may not be up to a permanent base station application. The first concern would be with weather. If you look at the SSB preamps, you'll see that they are enclosed in a weatherproof case with the connectors facing downward, and are inside of an RF sheilded case inside of that.
Second would be the power handling capabilities. Assuming that you don't have a sequencer, they are going to probably receive your full transmit power and need to be able to switch themselves. I don't see any mention of a safe switching sense power, so they may assume you're using a sequencer.
Third is that the power is being supplied over a non-shielded connection. If the power run is longer than (short?), then you may pick up some noise on it, which is then run straight into the box. The preamps I have use a separate coax line for power since they're shielded and since there's always some crappy RG-58 laying around.
Scott NW2S
Scott, In over 25 years or so of using them, I've never had that concern..
1. I put them in a weather proof box.
2. I put in a type N connectors.
3. I ALWAYS use separate feed lines. To me separate feed lines, spaced as far as physically possible is my answer to minimum crosstalk.... And at 85 years old, I'm not about to, or attempt to change my habits!!
4. I don't claim that is the way to do it, but it works for me....
Crappy RG-58 is never a part of anything in my system, and I have 19 holes in the wall of my house going to antennas, not all of them always used, but I do a lot of experimenting.
73, Dave wb6llo@amsat.org Disagree: I learn....
Pulling for P3E...