[aprssig] time for APRS second generation network?

[Greg Noneman]

On Jan 6, 2005, at 7:15 AM, Phillip B. Pacier wrote:

> Conditions have to be really good and the channel has to be relatively 
> clear, but here are the digipeaters I can regularly hit with my home 
> station:
>
> N6EX-4
> N6EX-2
> N6EX-1
> ONYX (K6TVI-1)
> WB6JAR-10
> W6JPL-2

That's a pretty interesting combination!  I can understand EX-4, EX-1 
and sometimes JPL-2 (low level digi).  The others are pretty tough.  
Onyx Peak has only a narrow slice of coverage into the LA basin (but in 
that slice, works pretty well).  It primarily looks out into the desert 
, but it covers a LOT of area.  EX-2 usually goes-away (approaching LA) 
right at about the Riverside-Orange County line due to blockage from 
the Santa Ana Mountains and the Chino Hills.  JAR-10 also usually gets 
blocked by the Santa Ana Mountains.  I guess you have found a SoCal 
APRS convergence :).
>
> I can also hit these when mobile down near the Disneyland area where 
> it is relatively flat.  Along the 22 freeway I can generally hit most 
> of these.  If not all six simultaneously, at least three or four.  The 
> problem is, it is rare for the channel to be clear enough to hit them 
> all or even a majority of them, but they all have the ability to hear 
> everything in the basin.  I have even seen my packets digid by K7GIL-1 
> and W6SCE-10 when the conditions are beautiful.

I would think GIL-1 would be pretty rare this side of the mountains 
(San Gabriel and San Bernardino).  It does shoot down I-15 south of the 
Cajon Pass, but I've never heard it get too far west of that.

> I agree with your suggestion to move N6EX-2 to a lower location, as 
> K7GIL-1 covers the high desert quite well and will spill enough 
> packets over the hill on most days I think.  ONYX is even higher than 
> N6EX-2 - perhaps we should look at making that a link digi instead of 
> a WIDE.  I haven't been able to tell how much N6EX-1 and W6JPL-2 
> compete, but I've always wondered if they do compete for a lot of the 
> same packets.  Do you have any data on that?

It all depends on availability of sites.  If a lower level site can be 
obtained, I think moving it outright would be best.  The history here 
is that Gil and I basically installed digis within days of each other.  
We didn't expect the overlap we obtained.  Crestline (EX-2) was 
intended to cover mainly south of the ridge into San Bernardino and 
some of Riverside counties.  It does this, but unfortunately sees too 
much to the north.

As far as EX-1 and JPL-10, here's the background.  EX-1 was the first 
APRS digi installed in the LA area.  Being in the San Gabriel 
Mountains, it covers most of LA county pretty well, except for local 
blockages.  JPL-2 was initially installed on a tall building in 
downtown LA to act as a temporary fill-in digi to support the LA 
Marathon.  It  offered coverage where EX-1 was locally blocked by the 
Santa Monica Mountains/Hollywood Hills.  Once it was there, the owners 
decided to leave it up.  I don't frequent that part of SoCal much 
anymore, but I would guess there's a fair amount overlap between the 
two digis, especially east  and south of downtown LA where EX-1 isn't 
locally blocked.

Hope this helps.

Greg
WB6ZSU