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[aprssig] VHF Mountain-toppers Unite!

Bob Bruninga bruninga at usna.edu
Sun Aug 14 17:19:12 UTC 2011

VHF Mountain-Toppers Unite!

(Revised to be IAW contst rules)

For the weekend of 10-11 Sept, (same as the VHF QSO party), a cadre of APRS mobiles and portables is going to man 15 or more mountain tops along the Appalachians from Maine to Georgia (and encourage others anywhere else in the country where mountain-topping is popular).

Their APRS radio will be on the HamIM APRS frequency of 147.585 (far from the weak signal band) and will be enabled for APRS digipeating.  Not only will they be able to see all the multi-op stations and direct contest rovers out there, but they will also digipeat any such multi-operator station beacons to others to provide a nice APRS tactical display. (Single-Op Contest Rovers are prohibited from digipeating their packets by contest rules, but muiti-operator stations can).  

These APRS packets have nothing to do with the contest or scoring, but are an opportunity to test our skills with ad-hoc VHF networking while there are lots of folks out playing radio at good VHF locations.  Everyone on the hilltops and valleys gets a great view of where everyone is located.

This kind of ad-hoc system will use the Shadow APRS  Emergency backup settings of a TEMPn-N network as follows:

FREQUENCY: 147.585 (the HamIM APRS frequency)
SYMBOL:    Rover or Portable (tent), etc
RATE:      Every 5 minutes


DIGIPEATER:  Everyone except single-operator score-submitting participants are encouraged to enable their radio's TEMPn-N digipeater:


With these settings, the ad-hoc TEMPn-N network is self-supporting.  Every well situated station (mountaintop or multi-op contest stations, not single-op Rovers) with a D700 or KPC-3 is enabled for digipeating. 

These last two digipeating set-up commands need to be permanently set in the Radio TNC via the serial port prior to the event.  (The D710 now has these in the front panel menu and default to always ON, but older D700 radios will need to be set via the serial port).  By making these settings permanent in all APRS radios, then, any radio, any time, can serve as an ad-hoc digi for others on demand, for anyone using the TEMPn-N path.

For details and background please see:

Make sure you test your station before the event!

Good luck in the Contest!  But remember the rules:

1) Single-op rovers are not allowed to use a digipeating path to extend their visibility, nor to digipeat others.

2) Multi-op stations may use APRS as noted above and may digipeat and be digipeaters and enjoy the view.

3) Anyone else (who does not submit scores) has no restrictions on how they use APRS during this event and are welcome to get their feet wet in VHF/UHF contesting too.


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