[aprssig] Simplex On the Road to Dayton

[Robert Bruninga]

I posted this over on the AMSAT reflector to add to the
fun of going to dayton... with APRS Voice Alert...

Operating "52" simplex on the drive to Dayton is FUN.  
But unless everyone is calling CQ every 5 minutes, 
many "vehicles can pass in the night" and not know it.

There is a another way to locate other mobiles that are
in simplex range of you and that  is to operate an APRS 
Voice Alert "radar" detector listening for any passing APRS 
Voice mobiles.   Simply monitor 144.39 with a radio that is 
TONE squelched to CTCSS 100. (eliminates all packet noise).

Normally you will not hear anything, becasue all the
packets that are coming from the national infrasctructure
APRS system digipeaters are transmitted without
any PL.  But most mobiles that have set up for 
APRS-VOICE-ALERT do include PL100 on their
transmissions and also listen by SPEAKER for any
calls using PL100.

Thus, if one of these mobiles (who is listening 100% of
the time on 144.39 CTCSS 100 with a quiet speaker)  
passes within 5 miles of you, you will hear his occasional 
PL 100 packet and he can hear your PL 100 voice call.   
So if you ever hear any packets (CTCSS 100 on 144.39)
it means someone is in DIRECT range of you and *IS* 
listening (CTCSS100).

Give him a call "CQ Voice Alert" and suggest a QSY
to "52" or any other common frequency.  You MUST
use the words "voice alert" in your call, because the
other driver is probably using a D700 and is probably
listening to other radios as well, and he will have no
idea that your call is coming in on 144.39 unless you
say so, because he would otherwise assume that
any voice he heard is comming in on the other band
of his radio or another radio in his car where it does
99.99% of the time.

Anyway, for those with D700's running APRS on
Band A and running 2m or 440 on Band B, this
gives them a "virtual 3rd radio" on a national
calling frequency (APRS) to which they are ALWAYS
listening.

Just thought the rest of the community might want
to listen for them on the long drive and make a
SIMPLEX contact when one comes into view...

de Wb4APR, Bob