[aprssig] APRS Voice Alert

[A.J. Farmer (AJ3U)]

Dave,

Voice alert is a good concept and it works with minimal interruption. 
I use it while mobile and it has allowed me to make a couple of
contacts on long trips that I otherwise wouldn't have.

Let me clear up the biggest misconception here: you don't "call CQ" on
the APRS frequency.  What happens is if there is another APRS user
within your simplex range and is also running voicealert, you will
hear their packet burst.  Then you can do one of two things: pick up
the mic and  say "voicealert - go to 146.52 to chat", or if you
prefer, check your station list and find who is close to you and send
them an APRS message.  If you choose to do the former, this is still a
very unobtrusive use of the frequency for two main reasons:  it is a
very short voice transmission, and as a mobile or portable station you
are low to the ground and have a limited simplex range.

The reason why this is handy is while mobile, you aren't going to be
checking your station list all the time, so you will miss another
station that might be close to you - and an opportunity to make a
contact.  Voicealert does that work for you by being your "ham radar
detector" as Bob calls it.

The voicealert concept does not promote calling CQ on the APRS
freqency, nor does it promote having a voice QSO there.  I think we
all agree that those are very bad things to do.  It is just a means of
knowing someone within your simplex range is active on APRS and is
willing to have a voice QSO.  Once you know this, you use this
knowledge to set up a contact on an acceptable voice frequency with
minimal impact on the APRS frequency.

Hope that helps!
--
A.J. Farmer, AJ3U
http://www.aj3u.com