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[aprssig] APRS in remote California - some results

Stephen H. Smith wa8lmf2 at aol.com
Thu Apr 27 15:44:05 UTC 2006

apratt at bestbits.org wrote:
> I set up an APRS rig on my motorcycle and did a ride through a chunk
> of California earlier this week, mostly for fun but partly to gather
> some data about coverage and path requirements off the major highways.
> A map and some observations are here:
>   http://www.bestbits.org/aprs
> Result #1:
> There are long stretches where I expected coverage but got no hits,
> along popular and well-covered roads like Interstate 5 north of
> Bakersfield and US101 south of Gilroy - and even CA-85 around San
> Jose. This makes me think my rig was intermittent, like the antenna
> flexed or grounded against something at speed. So all the data is
> suspect.
> Result #2:
> There appears to be no coverage at all (at any speed) east-then-north
> of Ridgecrest, through Trona and the Panamint Valley area. I did not
> enter Death Valley itself, but I don't expect coverage there either.
> Result #3:
> In those places where I hit anything on this trip, I never needed a
> three-hop path: two hops would always have been enough, even where a
> three-hop packet is the one APRS-IS decided to keep.
> I welcome other people's analysis and comments on the data and
> conclusions. Throughout the summer I hope to take more rides and
> develop more data for different areas. (Hopefully with a more reliable
> rig!)

Something is seriously wrong with your setup (or several digipeaters are 
off the air!). 

I-5 has essentially continuous coverage from the Mexican border to well 
beyond Redding in the north.  I've driven I-5 with my D700 (50 watts 
into roof-mounted Comet SB-14 6-2-450 tri-bander ant) many times and 
always have almost continuously heard the two-tone "my call" beeps 
confirming digipeats along the entire length.   Byond Yreka, I-5 gets 
spotty until you cross the Siskyous and enter Oregon's central valley.  
Then once again, continuous coverage clear to Vancouver, B.C. Canada. 

The holes on US-101 look suspiciously large also.  

There IS a tendency to "drive off the edge of the earth" east of the 
Sierra Nevadas.  Ironically, Death Valley actually does have fairly good 
coverage provided by very high digipeaters along the I-15 route between 
L.A. and Las Vegas. 

(Actually the I-15 corridor has pretty much continuous coverage from San 
Diego clear to Salt Lake City.   However, you lose it if you stray more 
than about 20-30 miles either side of I-15 in Nevada or Utah)

Stephen H. Smith    wa8lmf (at) aol.com
EchoLink Node:      14400    [Think bottom of the 2M band]
Home Page:          http://wa8lmf.com

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