--- In [email protected], "Mark" <n9...@...> wrote: > > John, > > I currently am Trustee for a TKR-820 operating on 444.5500. I wonder - is > this conversion "dual-mode" capable, meaning, can it be accessed BOTH via > D-STAR and analog radios, or does it render analog access unusable? I do > not want to do this if it eliminates analog access, since this is an > Emergency Management-affiliated repeater and many users in my area are not > D-STAR capable. As such, I'd have to maintain a dual-mode system, similar > to those using Motorola QUANTAR repeaters for digital (APCO 25) as well as > analog access. >
This approach would leave the repeater unusable for analog. However, there is a project using a soundcard that is working towards your goal, visit http://groups.yahoo.com/group/pcrepeatercontroller -- the wiring information would probably still apply, but rather than using a node adapter, you wire it to a cheap (unfiltered) soundcard. > Next questions is, my machine is a multi-receive site (read: SpectraTAC) > system - is the D-STAR processing done on the FINAL received signal before > being passed to the transmitter, or would I need to convert all the > receivers in the system to be compatible? In my system, I do not use the > internal receiver in the TKR-820 - I feed a voted signal in from the > comparator for repeat. > I am more of a square wave guy, rather than a round wave guy. But the basic answer is this, you need provide as pure of a discriminator signal as possible to the GMSK stage (whether a node adapter or a soundcard), no de-emphasis, or other filtering/shaping. If your voter can do that, then I see no reason that the GMSK signal couldn't be decoded and re-encoded to go direct to the FM modulator. All of this must be true FM, not PM. de K7VE
