Voice Alert for TM-D700 and other radios.

There are too many D700 users who are not aware of the VOICE ALERT feature that
really gives you three radios in one while traveling. This gives you a third
receiver on a single national frequency so that anyone at any time can call you direct by
voice, knowing that you ARE there and ARE listening.

Whenever you talk to another D700 traveler, make sure he is aware of Voice Alert.
The majority I talk to have never heard of this setting, and that is why I am making
this post.

Here are the settings:
	1) Set APRS mode on BAND A
	2) Use band B for all other needs (2m - 70cm - 23cm)
	3) Set CTCSS tone to 123 on BAND A (100 in the US)
	4) Turn up the silent volume on BAND A for Voice Alert
Done.

The CTCSS prevents you from hearing APRS packets on band A, but allows you to
hear Voice calls with PL 123, should anyone be trying to contact you. Hence,
a third receiver function that is ALWAYS ON, and ALWAYS on a known frequency, so
anyonce can contact you at any time by voice.

To call someone on Voice Alert, simply QSY to the APRS frequency, set PL 123 and
make your call:
	"W3XYZ this is W4ABC Voice Alert"
then agree to QSY to another frequency for chat. You MUST include the words
"Voice Alert" in  your call, or he/she will not know how it got to him. Your voice
will just come out of his speaker just like it sounds on the B channel, and won't
know the difference. He will push PTT and respond on B, and there will be a failure
to communicate. But if you say "Voice Alert", he will know to go to A to respond.

APRS RADAR:
Ah, but occassionally you may be within simplex range of someone else running
Voice Alert, and won't you hear his PL 123 packets? YES! But, of all the wall-to-wall
packets on the APRS channel, you won't hear ANY of them. But, you may hear one packet
from another Voice Alert mobile maybe once every 2 minutes while he is within a few
miles of you.
Don't think of this as an anouyance, think of it as a RADAR alert of the presence of
another APRS operator open for a voice call.

Several of us in our county with D700's use Voice Alert as a kind of back-door
voice channel to set up a QSO when the commuter repeater is too busy to get a word
in edgwise. Or, just a reminder that one of us is nearby...

But, the place where Voice Alert really shines is on long travels. The RADAR function
runs all day and will guarantee you a QSO if any other APRS mobile gets within SIMPLEX
range. Passing eachother at a combined speed of 160 Km/t means you are only within
range about 5 minutes max, so without APRS Voice Alert, you would never even know
it.

And, on average, you pass another HAM on the interstate about once every 15 minutes.
But, another APRS operator maybe only once an hour. And anyone can use Voice Alert,
even without a Kenwood. Any voice radio can set CTCSS on the APRS channel and monitor
for such travelers.

Never transmit PL 123 unless you are really LISTENING. It is irritating to hear
someone through your speaker on Voice Alert, but then not have them respond.

To hook up an external TNC mobile system, and still use Voice Alert, you can do
that only if you connect the TNC to the discriminator output so that it gets data
all the time, as CTCSS is muting the speaker.

Remember, APRS is supposed to facilitate local communicatisn between local operators.
The Voice Alert concept guarantees an open voice coordination alerting capability
between operators DIRECT at any time and anywhere. But of course, after the initial
call, do not stay on the APRS channel, but arrange to QSY for the QSO to avoid interfereing
with other local packets.

Bob Bruninga / WB4APR