[aprssig] APRS HT Event

Bob Bruninga bruninga at usna.edu
Tue Jan 18 10:21:20 EST 2011

> You did APRS on 445MHz. Was that on the 
> B or A side, at 1200 or 9600 baud?
> And you did voice on UHF also? What 
> gave you the full-duplex operation?

Yes, APRS on band B on 445.925 1200 baud.  Band A on 146.43 simplex.  They
worked independent and without any interference.  My acks could come in
while I was talking and the messages would get into HQ even while he was

We did not do voice-alert voice on the APRS channel because there was no
need, though it was a possibility.  Throughout the entire event I sent 60
messages and only had to send 2 twice before I got the ack.

With the D72 and its 100 deep message buffer, I  had a log of everything I
transmitted. In fact, it saved us!  One of the guys left at the end and
returned the loaned D7.  But HQ had not "received" the scores on three
sleds.  The entire event was being held up.  The guy had left.

Someone at HG decided to scroll back through the D7's message buffer (only
16 deep), but fortunately, the missing data was there (and ACKED by the

Bob, Wb4APR

Message: 11
Date: Sun, 16 Jan 2011 13:02:26 -0500
From: "Bob Bruninga" <bruninga at usna.edu>
Subject: [aprssig] APRS HT Event

Just completed our annual Klondike Derby with APRS HT messaging support.
Every hour, 20 stations reported scores from 20 scout outposts for up to 5
troops at a time.  We used APRS HT's for messaging the data to HQ, and a
D700 mobile display head on a clip-board at Headquarters for accumulating
the scores that  were then passed on to the computer data base operator. 

More information about the aprssig mailing list