[aprssig] 9600 APRS

[Curt, WE7U]

On Mon, 28 Feb 2011, Curt, WE7U wrote:

> On Sun, 27 Feb 2011, ml41782 wrote:
>
>> 9600 on VHF ?  I have never really seen this work on even on packet
>> I have seen 2400 & 4800 on VHF but a true 9600 no because of bandwidth
>> restrictions.
>
> There's no problem running 9600 baud on 2 meters, 220 MHz, or UHF in the U.S. 
> I've personally run 9600 baud on 2m.  We used to have a full-duplex 2m 
> repeater for 9600 baud in western WA.

To be clear, the G3RUH 9600 baud modem (The protocol we use for 9600 VHF/UHF) uses 4800 Hz modulation plus 2 symbols per transition to get 9600 baud throughput, phase-shift keying.  This is the modulation that sounds like slightly-reduced white noise if you have your squelch open listening to it.  If you don't have your squelch open, it doesn't open it.

-- 
Curt, WE7U.                         <http://www.eskimo.com/~archer>
    APRS:  Where it's at!                    <http://www.xastir.org>
   Lotto:  A tax on people who are bad at math. - unknown
Windows:  Microsoft's tax on computer illiterates. - WE7U.
The world DOES revolve around me:  I picked the coordinate system!"