[aprssig] HF APRS igates on fldigi

[Stephen H. Smith]

On 5/10/2020 11:27 PM, Joe Bennett via aprssig wrote:
> I'm all for moving off of 60 Meters. Look, it's a great band and I'm set up 
> there right now. The lack of automatic control makes it undesirable for a lot 
> of the core functions of APRS. 40 or 30 meters would seem to be a better 
> alternative..
> 
> 
> 
> -- Joe
> KA3NAM
> 

30 meters has been used for over 3 decades for HF AX.25 packet APRS. 
Approximately a dozen 30M igates scattered around North America (including mine 
in central MI) monitor the channel 24/7. You can monitor and transmit 30M 
300-baud packet APRS by setting your radio to 10.147.60 USB and setting a 
hardware or software TNC (such as the UZ7HO Soundmodem) to use 1600/1800 Hz 
"KAM" tones. TNC2s and clones (such as the MFJ-127x series) also use this tone 
pair in the 300-baud HF mode. An alternative for a transmit-only "tracker" is 
to use a TinyTrack 3 programmed to 300-baud HF mode (rather than the usual 
1200-baud VHF mode).    I have used a Yaesu FT-857 with a single-band 30M 
"Hamstick" whip in the mobile with with great success for many years.

Long-Range APRS on 30 Meters HF
    <http://wa8lmf.net/aprs/HF_APRS_Notes.htm>

For the last 11 years, the classic packet APRS was joined by 
APRS-over-PSK63-and-MFSK16 courtesy of a single application "APRS Messenger". . 
   This program,  written by G4HYG, combined a waterfall soundcard modem for 
these modes, a split-screen send/receive terminal, a serial interface for a GPS 
for tracker mode, and IP sockets that allowed it to function as an igate.

The performance of MFSK16 on HF was an ORDER-OF-MAGNITUDE better than classic 
AX.25 packet on HF.   For many years, my 30M HF receive/igate setup ran the 
"UZ7HO Soundmodem" for 300-baud HF packet, and Messenger for PSK63/MFSK16 
side-by-side.
    The MFSK16 mode would allow flawless keyboard-keyboard APRS messaging at 
times when the 30M band sounded totally dead; it would copy signals reliably 
even when you could hear NOTHING in the speaker.  I was living in Pasadena, CA 
at the time, and could carry on APRS message conversations from my mobile in 
Los Angeles or Las Vegas to stations in the MidWest almost any time of the day 
or night.
    Then quite abruptly, the author took down the website for the program and 
stopped distributing it in December 2019. He claimed compatibility problems 
with Windows 10, though I didn't have any problems when I tried it on a Win 10 
setup.  I suspect he just didn't want to spend the ever expanding amount of 
time supporting configuration issues. (The author owns and runs "Cross Country 
Wireless", a small mfr of radio accessories like active receive antennas, 
filters, etc.)

My experimentation with FLdigi KISS is an attempt to bring back the 
extraordinary capability of MFSK16 to APRS.

    Shortly, I will add the FLdigi MFSK mode to my 30M igate setup.


As I explained in the long post at the beginning of this thread, I am 
particularly interested in 60 meters because of it's NVIS (high-angle skywave 
operation) propagation that allows 0-400 to 500 mile propagation without a skip 
zone. 30 or 40 meters normally have a skip zone of 150-350 miles, meaning you 
won't hear stations closer than that.
    From my QTH in central Michigan, 60 meters means I can hear anything in 
Michigan (including the remoter regions of the Upper Peninsula), Ohio, Indiana, 
Illinois, Wisconsin and Western Ontario quite consistently. These areas are 
inaudible for me on 30 meters - they are too close.

As I pointed out before, I have in mind not only the typical stand-alone 
beacons, but also the Mic-E mode of sending position bursts each time you unkey 
on a voice transmission.  60 is uniquely suited to this, since it's the only HF 
band NOT segregated between voice and non-voice data modes.  You can freely 
intermix voice and data on any of the 60-meter channels.

__________________________________________________________

Stephen H. Smith    wa8lmf (at) aol.com
Skype:        WA8LMF
EchoLink:  Node #  14400  [Think bottom of the 2-meter band]
Home Page:          http://wa8lmf.net

-----   NEW!    60-Meter APRS!   HF NVIS APRS Igate Now Operating  ------
    <http://wa8lmf.ddns.net:14447/>



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