[aprssig] APRS on all Radios!!!!
noskosteve at yahoo.com
Sun Aug 17 02:04:24 CDT 2008
Sounds like DPL commonly called DCS. Needs careful thought/design. This is a problem for Phase/Reactance modulated rigs because of the potential for very low freq components in the data string. It's a balance between that and making some audible stuff on the high end. DPL has very carefully selected codes (no long same bit strings) and encoding algorithm, yet still needs very good low freq response in the TX modulator.
Direct FM imodulator is better, but the radio needs the appropriate low freq response as well.
73, Steve, K9DCI
--- On Sun, 8/17/08, Robert Bruninga wrote:
> ... Scott, looks like you can have a new project.
> > Make a dongle for these P25 radios that takes
> > GPS input and sends out the right bits for APRS.
> > Lets define the format... Howabout something
> Woahaaa! Make it for ALL radios TOO.!!!!
> Make it encode data at say XX Hz (in PL range). Plug this
> into ANY FM radio that has an external TX modulation input (that
> goes down to XX Hz). Then instead of PL, this station sends his
> XX Hz data..
> Make a RECEIVE dongle tht plugs into the REPEATER receiver
> (on the discriminator) so it can decode the XX Hz data. This
> dongle then converts the data to APRS format as I described below.
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