Order Tray | Contact Us | Home | SIG Lists

[aprssig] More digis are changing to the new paradigm

Tom Russo russo at bogodyn.org
Tue Jul 5 01:16:55 UTC 2005


On Mon, Jul 04, 2005 at 08:21:28PM -0400, we recorded a bogon-computron collision of the <bruninga at usna.edu> flavor, containing:
> Earl,
> I sympathize with your plight...
> 
> >>> needhame1 at plateautel.net 07/04/05 5:04 PM >>>
> > The world is different everywhere you go -- you have 
> >50 stations within about 66 miles, I have 50 within 96
> http://66.78.35.146/cgi-bin/near.cgi?call=KF4OTN and 
> http://66.78.35.146/cgi-bin/near.cgi?call=Kd5xb-2 )
> 
> Ah, but in New Mexico, with all those mountains, Isnt
> it easy to go well beyond 96 miles and still only use
> 3 hops?   Again, I am not that familiar with that area,
> but 3 hops even here back east can easily cover
> 96 miles.   I thought in NM, that 3 hops can get anywhere
> in the state?  (nice mountains)...

As a New Mexico APRS user in the center of the state, that is certainly the
case where I sit.

The 144.39 channel is nowhere near saturation at the moment, but with the
vast number of digis in the state and their positions on really tall mountains,
adding just one hop increases the noise.  When the URFMSI digis dropped RELAY
and WIDE (the biggest change they made in adopting new n-N), the channel
became much, much quieter.  It is now clear about 40%-50% of the time.  

Still, at my home station my calculated ALOHA range is 107 miles and contains
16 "mobiles in motion", 6 "other mobiles", one WX station, and 7 home stations.
The ALOHA range is that short due to the presence of 14 digipeaters inside that
range, all of which can be hit from my station with one or two hops.  WIDE3-3 
is overkill in this part of the state, and while the channel is not severely 
congested it was pretty bad only a few months ago, mostly from RELAY,WIDE mess 
and trackers set to beacon two to three times per minute. 

I hear stations from all corners of the state using 3-hop paths.  I get tons
of 5-hop stations from out of the state, most of them on their third or fourth
hop.  My current screen shows 250 stations heard on RF --- about 97 of which
are digis, and many of which are as far away as 600 miles, using WIDE7-7
paths.

We use APRS in Search and Rescue operations here near Albuquerque and Santa
Fe, and every bit of unnecessary channel loading decreases the usefulness of
man-portable low-power trackers.   From my POV as a search and rescue field
coordinator, it's far less important that I hear tons of stations all the time 
than it is to hear two or three specific low-power portable stations when I need
to.  I for one appreciate it when folks keep their paths down to the 
minimum necessary to get the job done.

And as I pointed out to Earl privately just a little while ago, the powers that
be who changed the URFMSI digis did so in such a way to allow WIDE5-5 to 
continue in the Clovis area --- the handful of digis out there only trap paths
of WIDE6-6 and WIDE7-7.  Most of the others in the state will trap anything 
longer than WIDE4-4.  None trap paths shorter than that.

-- 
Tom Russo    KM5VY     SAR502  DM64ux         http://www.swcp.com/~russo/
Tijeras, NM  QRPL#1592 K2#398  SOC#236 AHTB#1 
 "The only thing you can do easily is be wrong, and that's hardly
  worth the effort." -- Norton Juster




More information about the aprssig mailing list