The Icom repeater receiver has very poor selectivity and we found out that we needed to install band pass cavities between the receiver and the duplexer so that the receiver could hear weak signals.
You can verify this by monitoring the RSSI port on the receiver. Better yet, perform the NU5D modifications. I was glad that I did when the troubleshooting began! It is found here: http://www.hamradio-dv.org/icom/DstarRptMods_NU5D.pdf Without the band pass cavities, the RSSI voltage was around 4 volts all the time through the duplexer. When I added the band pass cavities the RSSI voltage dropped under 1 volt. You are experiencing receiver desense because of the poor selectivity in the ICOM receiver. You can view our D-Star installation report at: http://www.utahvhfs.org/dstar_repeater_installation.html John Lloyd, K7JL Utah VHF Society Lot wrote: > > > Hi Everyone, > Our club bought a Dstar Repeater (IDRP4000v & IDRP2C). > For some reason the receive sensitivity is very poor. We can access the > repeater no more than 2 miles away maybe even less. We decided to send > the IDRP4000v to Icom for service and they told us that all is well and > found nothing wrong with it. > > Now I was thinking , could it be the controller that is at fault? > Or could it just be the cat5? Or is there something we forgot to do? > > Now we plan to send the IDRP2C to Icom for service checkup. > But before we do, can you guys please send us information on how to > proceed? > > Any info will be very much appreciated. > Regards! > Lot / K6IRF > http://www.harpusa.org <http://www.harpusa.org>
