We have an experimental 440 MHz analog
repeater that has been converted to D-Star. The GM300 radios have been
interfaced using a GMSK node adapter.
The node adapter is in a duplex configuration, so in reality it has nearly all
the functionality of an Icom D-Star repeater.
A D-STAR repeater is an expensive proposition. And many people are not happy with the Icom D-Star repeater performance. It's a number of things, most notable the poor receiver sensitivity. ~.45uV... In many cases the "repeater" is nothing more than two 28XX series radios in a rack mount box ... Pictures in the d-star digital yahoo group confirm this. Receiver desense is also on the list due to the use of plain-jane RG-58 inside the units.
Apparently the Icom G2 software is also not impressive, as discussed on the D-Star Gateway mailing list back in November.
To build this adapter the cost about $100 (+ your analog radios) as compared to the cost of a Icom RPC-2 Controller plus a RF band module at about $2900.
For now, the frequency is 441.4625 +5 (SNP) The 40 watt GM300 radios are
running cleanly at 20 watts.. The repeater is located in the village of Allouez
near Heritage Hill State Park. The antenna is a Comet GP-6 Omni (9 dB), at about
35 feet. It is fed with LMR-400 coaxial cable. It appears to have about a 15
mile coverage radius.
Maxtrac/GM300 radios have a jumper inside (JU551) that sets whether the external connector will have flat or discriminator audio. You want flat. You may also need to add some 10 uF DC blocking caps on the RXA and TXA lines.
For more Information on the GMSK/ DSTAR Node Adapter/ Hotspot, please visit the websites below:
Specifics on node adapter setup
You may also want to take a look at John, K7VE's recent blog where he converts a Kenwood repeater for D-Star.
KI4LKF Development History: