[OZAPRS] Low cost HF Modem

[Bob Bruninga]

On Tue, 4 Nov 2003, Richter, Mike W wrote:

> Does the Tigertronics use the compressed MicE format - if not then the
> full-length format will be more error-prone on HF.

You bet, a full size APRS packt on HF lasts almost 4 seconds!  Thus,
timing must be NEVER on the order of minutes, but say once every half
hour or so.  If one is using HF, then it is long-haul and there is no
need for frequent position reporting so that the channel can be shared.

The Mic-E format on HF would last about a second..

Bob
>
> Mike Richter   VK2BMM > >
> -----Original Message-----
> From: Steve Davis [mailto:steve at zl2ucx.gen.nz]
> Sent: Wednesday, 22 October 2003 04:42 pm
> To: ozaprs at marconi.ics.mq.edu.au
> Cc: zlaprs at nzart.org.nz
> Subject: Re: [OZAPRS] Low cost HF Modem
>
>
> Mike, and others that have responded on this thread.
>
> (copied to ZLAPRS list for interest)
>
> We need to keep the same as existing HF 300bps packet, as there is
> already a reasonable amount of gear being used out there.
>
> Have a look at the Tigertronics TM-1 Tracker. At $US90 it is not as
> cheap as a TT3, but in general is cheaper and smaller than buying a
> new GPS capable HF TNC.
>
>    http://www.gpstracker.com/tm1.htm
>
> I believe that there are a few in use in VK and ZL already.
>
> I just have become a dealer for Tigertronics equipment here in NZ,
> and will have some in stock shortly.
>
> 73
> Steve
>
> > To get more people operating on HF, it would help to have low cost
> > APRS encoder and Modulator.
> >
> > Byon is currently looking at reviewing the TinyTrak 3 design. It
> > wouldn't be hard to have a configuration option to send the data at
> > 300baud rather than the usual 1200 baud.
> >
> > Byon will only add this option if there is a demand for it - if you
> > want to see it add your comments to TinyTrak at yahoogroups.com
> >
> > Mike VK2BMM
>
>
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>

de WB4APR at amsat.org, Bob

PCsat WEB  page     http://www.ew.usna.edu/~bruninga/pcsat.html
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