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[aprssig] Regional Voice Alert VHF/UHF Plan C.

Robert Bruninga bruninga at usna.edu
Wed Dec 5 17:44:45 UTC 2007


OK, plan C (for the alternate APRS local channel to support
priority local emergency and special event operations).

This one is just a single VHF radio, and a KPC-3+TNC and a
simplex voice recorder (About $10?).  Lets see if this works...

1) RX on 144.99, TX on 144.39 normal digi
2) Voice recorder records any PL100 VOICE on input
3) KPC3+ mute ckt ignores recording of PL100 packets
4) Voice recorder repeats only voice on 144.39

This gives:
A) Priority to local APRS data on 144.39
B) QRM free higher reliability local APRS input
C) Ability for VAlert to cover broad area
D) All of this on Band-A of D700 or using only a single band
APRS radio.
E) D700 band B's can support all other comms.
F) Lets local APRS operators shift 144.39 +600 in support of
this emergency event or special event and have priority
communicaitons which includes the occasional area-wide Voice
Alert.  All on Band A of a D700 or D7 or on a single band VHF
APRS radio.

Bob, Wb4APR



> -----Original Message-----
> From: Robert Bruninga [mailto:bruninga at usna.edu] 
> Sent: Wednesday, December 05, 2007 12:00 PM
> To: bruninga at usna.edu; 'TAPR APRS Mailing List'
> Subject: Regional Voice Alert VHF/UHF Plan B.
> 
> Still pondering... another idea for the ultimate local
dedicated
> APRS support system using a pair of VHF and UHF transceivers
and
> KPC-3+ TNC is to configure them for this arrangement:
> 
> 1) VHF and TNC Acts as 144.99 ==> 144.39 digi
> 2) UHF input gives regional Voice Alert out on 144.39
> 3) Mobile VAlert from 144.99 goes to UHF voice output
> 
> Here is what you get:
> 
> Netcon or anyone can call everyone in the region on Voice
Alert
> via the UHF input.  Mobiles can QSY their A-Band and APRS to
the
> 144.99 input (keeping 144.39 output so they still see
> everything).  But being on the 144.99 local input, their
packets
> have 95% less QRM and are much more reliable and when they are
> digipeated onto 144.39, they get local priority.
> 
> While their mobile TX is on 144.99 (where the channel is now
95%
> clear), any of their Voice Alert transmissions on their radio
A
> side will not QRM anyone on 144.39, but their voice will be
> relayed on the UHF output.
> 
> So these APRS operators now have full PRIORITY local APRS
> digital communications AND local wide area APRS VOICE (back
> channel) communications on the A side of their radio and their
B
> side can still be used for their other needs.
> 
> Oops.. I guess they need to listen to the UHF channel to hear
> the other non-simplex APRS voice Alert comms from the cross
band
> repeat.  So this kinda takes away from the freedom of band B.
> 
> Hummh..  Need a plan C.  Next message...
> 
> Bob, WB4APR
> 
> 
> > -----Original Message-----
> > From: aprssig-bounces at lists.tapr.org 
> > [mailto:aprssig-bounces at lists.tapr.org] On Behalf Of Robert
> Bruninga
> > Sent: Wednesday, December 05, 2007 8:19 AM
> > To: 'TAPR APRS Mailing List'
> > Subject: RE: [aprssig] Solar Powered Digi's and Voice Alert.
> > 
> > >> One way to greatly facilitate TEAM operation on 
> > >> APRS is to put up a cross band transceiver for 
> > >> area-wide VOICE alert.  The input is on UHF 
> > >> (with PL) and the output is on the APRS channel
> > >> with PL-100.
> > 
> > > ...  Do you envisage it being used like a wide area 
> > > pager or something like that?
> > 
> > Hey, that is a pretty good analogy.  In fact, here is
another
> > idea to greatly improve APRS performance in a SPECIFIC
> > geographical area, such as to support your local ARES/RACES
> > county communications:
> > 1) Install the above cross band repeater for voice alert
> > 2) Add a DIGI at the same location on 144.99 (if avail)
> > 
> > When a local net is activated, the call goes out on Voice
> alert
> > asking everyone to QSY to the local APRS packet channel.
And
> > the voice alert cross band can also output on that channel.
> > Here are benefits:
> > 
> > 1) The local channel does not have the QRM from out of area,
> so
> > the channel load drops to only 5% of what it normally is.
> This
> > improves APRS reliability by a factor of 20 or more, even
low
> > power trackers can 
> > Be operating there without being clobbered.
> > 
> > 2) With the 95% additional free-air time, the brief
> voice-alerts
> > will have a much much less chance of colliding with anyone.
> > 
> > 3) Mobile D700 users now get full voice alert info, full
local
> > APRS coverage, and their BAND-B is still available for their
> > other needs.
> > 
> > Something like that.
> > 
> > Bob, WB4APR
> > >> This way, voice alert is extended far beyond 
> > >> simplex to actually cover your entire local 
> > >> area.  This way, all APRS stations can
> > >> instantly make a voice alert to ALL stations 
> > >> in the area, no matter what they are doing 
> > >> with their other radios.
> > >>
> > >> Of course, this is pandora's box.  Over use, 
> > >> by one or more individuals could drive everyone 
> > >> nuts and cause them to turn off voice alert.  
> > >> But in my mind, it is a GREAT backup emergency
> > >> alert system.  If rarely used...
> > >>
> > >> Think of it as an APRS 911 system.  
> > >> IE, never used, but available for when you 
> > >> really need it.
> > 
> > 
> > _______________________________________________
> > aprssig mailing list
> > aprssig at lists.tapr.org
> > https://lists.tapr.org/cgi-bin/mailman/listinfo/aprssig
> > 
> 
> 





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