On Nov 27, 2009, at 9:00 AM, john_kc4yi wrote: > I have been following the post on receiver preamps. I would like to expand > the topic to D-Star repeaters. The project that I am working on is a 2 Meter > D-Star repeater. > > The core of the system is an ID-RP2C and the ID-RP2V. I will be running on > 145.12 with a - 600 Khz split. The antenna is a four bay Comprod antenna fed > with 900 ft of 1 5/8 inch line. The coverage area is flat. The transmitter > should run about 50 watts out of the duplexer and the receiver should decode > at about -115 dbm.
Decode audio only, or fully decode the non-error corrected low-speed data (callsigns, serial port, etc.) -- There's two distinct "detect thresholds" with D-STAR. You're shooting to optimize the data performance. Going by voice decoded (which is Forward Error Corrected) will leave users a bit miffed when their calls don't route properly. Maybe you already know that, but just sayin'. > I am interested in examples of existing proformance enhanced D-Star 2 Meter > repeaters that are on the air and or ideas to try. I don't want to reinvent > the wheel. If you have links to existing articles, please post the links. The Utah VHF FM Society seems to have done the most detailed "engineering level" discussions of D-STAR testing -- you might want to start there for theoretical knowledge, and then talk to the folks in California for "real-world" performance gains they've accomplished via pre-amps, off-board PA's, etc. They seem to be the furthest "ahead of the curve" on actual application. 'Round here our D-STAR group is too poor to implement most of the things they've done. Especially the PA and heavy-hitter filtering. -- Nate Duehr, WY0X n...@natetech.com http://facebook.com/denverpilot http://twitter.com/denverpilot
