It doesn.t I've seen this being said before, but decided to not comment. It's a bi stream at a given rate, which results in a filtered modulation signal, but the b/w of that mod signal is less than the bit rate. --f
_____ From: [email protected] [mailto:[email protected]] On Behalf Of John Hays Sent: Thursday, May 14, 2009 8:40 PM To: [email protected] Subject: Re: [DSTAR_DIGITAL] Re: External D-Star encoding. I'm not sure the 4800hz statement is correct. The data stream is 4800 bits per second which is put through GMSK before hitting the radio which requires a pretty flat response, which is why it is injected into the modulator directly (not through the audio chain) and pulled directly from the discriminator. I don't think the 4800bps directly maps to 4800hz. On May 14, 2009, at 10:42 AM, Jonathan Naylor wrote: > > > > Generally, is the encoded D-Star signal too delicate to feed over > a mic/speaker input/output (in the way that APRS is)? > > APRS is usually done with 1200Bd packet, which uses tones of 1200 > and 2200 Hz (I think), which fit nicely within the audio filters > that most radios have. D-Star uses a maximum frequency of 4800 Hz > and therefore wouldn't pass through those same audio filters. > > Jonathan G4KLX (working on a PC based D-Star system) > > . > > John Hays Amateur Radio: K7VE [email protected] <mailto:john%40hays.org> [Non-text portions of this message have been removed] [Non-text portions of this message have been removed]
