60 Meters APRS Test Comparing 300 Baud Packet with VARA

This test was conducted on 10 Feb 2024 on a trip from East Lansing, MI to Traverse City and back for a ham fest. The intent was to compare the relative performance of traditional 300 baud HF AX.25 packet with the VARA high-performance data modem.

The test setup in the car consisted of a Panasonic Toughbook CF-51 with a Behringer UCA-202 USB sound card running through a home-brew tone-activated sound card interface into a Yaesu FT-891 transceiver. 
    The antenna was a Quicksilver Radio house-label "Ham Stick"-type mono-band whip, body-mounted on the left-rear fender of the car. The tests were conducted on 60 meters US "channel 5" (5.403.5 MHz USB).

Two copies of UIview in separate folders were used - one linked to the UZ7HO Sound modem for 300-baud HF packet, the other linked to the VARA-HF modem.  Both instances of UIview were set to beacon every time the position changed by 2 km.   The Soundmodem and VARA were set to use the same sound system alternately.

[The tone-activated interface makes this very easy to do - there is no problem with two soundcard programs contending to access the same serial port or CAT controls at the same time.]

The receiving setup at my home QTH consisted of another Yaesu FT-891 connected to a mini horizontal dipole made from two more of the same Ham-Stick type mobile whips positioned about 12 feet (3 meters) above ground to enhance short-haul NVIS receive.

The trip up was conducted during night-time hours, when propagation on 60 meters is very long -- typically 500+ miles (800 + km).  Various hardware configuration issues spoiled the outbound night-time test. No useful data was collected.

The return trip started about 1:30 PM local (US EST) and ended about 6:30 PM, spanning a time period from full daylight through twilight into early evening after dark. Everything worked perfectly this time. Short-haul NVIS propagation (0-250 miles / 0-375 km) was clearly performing very well during this entire time period.

The two maps below are recalls of 12 hours of history from APRS.fi. The first one is WA8LMF-2 -- the classic packet beacons.  The second one is WA8LMF-3 -- the VARA beacons.  It is very clear that far far more VARA beacons were successfully received than packet beacons, even with the slight advantage of the packet beacons using the enhanced forward-error-correcting variant of packet known as "FX.25".

WA8LMF-2  (Using classic 300 baud HF packet enhanced with "FX.25").
 

WA8LMF-3  (Using VARA-HF modem)