So this weekend I did some observations of the various radios connected to my ST-2 in the attic. In the original layout this fed a 4-port MCA204M active multicoupler, in turn this fed 2 8-port actives and a second 4-port active, with the last port going directly to an R8500. I monitored a few systems I am familiar with in the area and observed signal level indications as well as voice quality on channels like ATIS, NWS and other active channels.
I then swapped out the 4-port active and inserted the 4-port passive MC204. This improved the voice quality on some weak signals but did not change the indicated signal strength on any of the radios. The R8500 has a much more reliable relative signal strength indication and on each channel it was pretty much unchanged.
I then put a JIM M-75 pre-amp in before the 4-port passive that feeds the 8-port actives and that increased the indicated signal level pretty dramatically but caused no discernible difference in voice quality. There is an ATIS channel that I can only hear sometimes here and it came in pretty fairly well with this set up, better than without the pre-amp. I was unable to hear it with the antenna connected directly to either the R8500 or several of the scanners.
I usually avoid cheap amps like the JIM but it seems to work pretty well here. I live in a development out in the desert, 15 or 20 miles away from the nearest town. The noise floor here is pretty minimal and overload is not as big an issue. For those reasons my results are not typical of a city or suburban user.
This all said, I am still considering the MiniCircuits solution down the road. This would likely provide even better results than the Stridsbergs are now. I would probably try to put the amp up at the antenna but I don't know how well it would survive in an attic in 120 degree heat during our summers.
I then swapped out the 4-port active and inserted the 4-port passive MC204. This improved the voice quality on some weak signals but did not change the indicated signal strength on any of the radios. The R8500 has a much more reliable relative signal strength indication and on each channel it was pretty much unchanged.
I then put a JIM M-75 pre-amp in before the 4-port passive that feeds the 8-port actives and that increased the indicated signal level pretty dramatically but caused no discernible difference in voice quality. There is an ATIS channel that I can only hear sometimes here and it came in pretty fairly well with this set up, better than without the pre-amp. I was unable to hear it with the antenna connected directly to either the R8500 or several of the scanners.
I usually avoid cheap amps like the JIM but it seems to work pretty well here. I live in a development out in the desert, 15 or 20 miles away from the nearest town. The noise floor here is pretty minimal and overload is not as big an issue. For those reasons my results are not typical of a city or suburban user.
This all said, I am still considering the MiniCircuits solution down the road. This would likely provide even better results than the Stridsbergs are now. I would probably try to put the amp up at the antenna but I don't know how well it would survive in an attic in 120 degree heat during our summers.
