[amsat-bb] Re: Email via Satellite Simulated Emergency Test
nate at natetech.com
Mon Nov 5 15:14:08 PST 2007
On Nov 5, 2007, at 3:26 PM, Bob Stewart wrote:
> Bob can you or anyone tell me if there are software TNCs for
> soundcards out there? I know almost nothing about APRS or
> even where to turn to get useful information. Unfortunately,
> buying a TNC is simply not going to happen at this time. I am
> a Linux user.
In the "early" days of packet radio, TNC's or "Terminal Node
Controllers" were often used because the PC's themselves had little or
no soundcard support, and most folks were comfortable with external
modems for calling BBS's, and later dialing into the early Internet.
TNC's are still available for specialized functions like acting as
standalone digipeaters (a TNC and a radio on a mountain, no computer
required), etc... and some people still like them for other reasons...
but they're FAR more expensive than software on a PC, a sound card,
and a simple audio and keying interface to the rig, nowadays.
Too bad most of the "official" books from ARRL and others on the
subject still have 1980's black and white photos of TNC's to guide the
new hams doing this stuff off into oblivion.
But most "modern" digital setups include at least one connection from
the sound card of a modern PC to a radio directly or via one of the
many interface "boxes", which are just a nicer way to package up all
the connectors and possibly some isolation electronics to isolate the
PC (an excellent RF noise generator) from the rig, and also to provide
simpler "plug and play" connections for things like keying logic from
the PC to the rig.
The TigerTronics website has a good listing of a whole bunch of
software that will work with soundcards, for example, since they sell
one of these interfaces. (A pretty good one too. They also sell the
TigerTronics Signalink USB which contains a USB-based sound chipset
that "looks" like a secondary sound card to the PC, which has a VOX
circuit for keying).
There's a LOT of ways and a LOT of software out there for the various
digital modes that will work with a sound card, a simple audio
interface and some way for the PC to key the rig. Almost too many to
describe all the options.
What kind of rig do you have Bob? Perhaps the group can tell you the
easiest and cheapest way to get it going for APRS. Some software is
free, other software costs a few bucks, but it's far cheaper than
anything using a real TNC will be.
Nate Duehr, WY0X
nate at natetech.com
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