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[aprssig] PropNET Lessons Learned [was: 6m MS network Performance Monitoring!]

Ev Tupis w2ev at yahoo.com
Fri Jan 4 11:47:00 UTC 2008


I would like to offer insights.  None of them should be construed as poo-poohing the possibility of using 6m FM AX.25 for emergency e-mail support systems.  Instead, they are shared as lessons learned, upon which you can build for greater success in your efforts.

Based on PropNET-based Meteor-scatter experiments in the past...

--- Equipment Parameters (EP) ---
1. FM Tramsceivers (converted and tweaked Motorolla rigs)
1a Open squelch (see 5a below)
2. 100-watt RF output
3. 100-ft of Belden 9913 cable
4. Ringo Ranger vertical
5. KPC-3 TNC w/ROM 8.2, configured with...
5a Ignore carrier detect

--- Operational Parameters (OP) ---
1. Followed the 4-quadrant TX/RX model
2. Followed the 15 seconds of continuous TX/ 45 seconds of RX model
3. 53.530 MHz used for several trials, 50.620 MHz used for others

--- Reasons ---
EP1 - FM mitigates Doppler shift.
EP1a- to decode weaker signals
EP2 - More ERP = greater opportunity for success
EP4 - The "radient" of a meteor burn is random.  The "radient" of a meteor shower is constant only from a cosmological perspective.  From an earth-based observer's perspective, it appears to move as the earth spins.  The Leonids shower appears to come from the constellation Leo.  That constellation moves in the sky relative to any one observer on earth, as the earth spins on its axis.  An omnidirectional vertical assures that RF is always bathing the entire sky in all directions.
EP5a-For MS experiments, you don't want local participants "holding off" your TX.  There is assumed QRM from all participants in the same quadrant

OP1 & OP2 - these were Bob's recommended strategies for the reasons posted on his web page

--- Major Lessons learned ---
With these parameters, it is obvious when meteor events occur and when they end.

1. Receptions ceased when meteor events ceased.
2. Even during meteor showers, the number of reported receptions were statistically small when compared against the number of transmissions occurring.
3. Clocks migrated.  People in quadrant 1 were often found TXing during times when they should have been RXing.

--- Conclusion (as I wax poetic) ---
The human spirit can find ways to be successful in whatever it chooses to focus its' effort upon.  Use the above information only to avoid the pitfalls of those that went before you as you attemp;t to find a path to the destination that you're pursuing.

I can offer additional information that may help, but will let this settle for now.

Best wishes, truly!
Ev Tupis, W2EV





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