[aprssig] Digis everywhere

[Dave Baxter]

Hi...

Re:-  "ANy old TNC and old HT laying around could be used."

I don't know what the airport RF site regulations are like over there,
pretty lax I'd guess if you can put old "Ham" gear up and operational on
site at commercial airports.

Here, in the highly unlikely event they (The CAA and BAA, not to mention
OFCOM, and that's just in the UK) would even think of permitting this
(excellent idea it has to be said) the equipment used would have to
conform to the stringent RF purity and stability spec's specified for
all the other aeronautical and commercial ground comms used on site,
much as our existing repeaters also have to, plus shutdown procedures
would need to be in place too etc.  Permission (well, lack of objection
more to the point) from all the other operators and users on the same
site would also be needed.  Many just blanket refuse Amateur
applications as that's the cheapest (for them) option.  We're talking
not only the Airport people, but police, fire, ambulance, security,
taxi, individual airline co's etc etc...

Then there is the cost of renting rack and tower space, at commercial
rates.  Little if any these days is free or discounted to "Ham" systems
any more, on commercially operated sites at least.  Several voice
repeaters, and scores of original digi's have gone off air for this (as
well as other legislative) reasons in the past few years in the UK.

If we could get that sort of thing done, nice, it'd make Packet Radio,
and APRS truly usefull for the (fortunate few) of amateurs who travel
regularly.  But in the event of any unusual QRM to any of the
commercial/aero' frequencies, guess what the first system to be shut off
would be.

Anecdotally, in the past where I've known there to have been
"interactions" between co-sited commercial and amateur systems, it's
usually been the commercial kit at fault, often after a site visit by
another user's maintenance people (not the users whose kit was found to
be causing the trouble!)  But We (the "Amateurs") always get the first
blame.

No reason I think why we couldn't put up something like an informative
digi at an existing amateurs location near an airport.  But there again,
any "traveller" would be unlikely to get to use it, due mainly to the
unprecedented hassle in most airports when you pass through them, and
the massive existing QRM from all the afore mentioned co-existing RF on
site.  the D7 not having a particularly good reputation for out of band
or adjacent channel rejection.  At least the D7e I have is not that good
I find.  From memory, not much "Ham" hand held stuff is, sadly. (built
down to a cost, not up to a spec')  Ex commercial gear is better of
course, but though there is a lot of that about, most of what is
available, does not meet the currently active specifications, which is
why it's on the surplus market in the first place.

Nice idea Bob, if you can do it on some airports in the US, excellent,
I'll try it next time I fly into the US, if I can get my D7 in the hand
luggage that is (more hassle!).  If I get my "collar felt" by airport
security, I'll say "Bob Bruninga said it's OK", I'll let you know what
there reply was when they let me out. ;-)

Elsewhere in the world, and Europe and the UK in particular, I'm 99%
sure it's a no-go, sadly, for "on site" digi's at least.

The other bigger problem, is trying to remember how to read all the
acronyms and abbreviations, as shown all to briefly on the D7 screen.
I've no doubt some can do it from memory, I can't that I do know.

Another other problem (opertunity?) is how to tell the arriving
traveler, what the local APRS working frequency is.  144.390 is well
known world wide as used in the USA, and 144.800 for Europe?  And there
seem to be one or two others in use elsewhere arround the globe too.

In Florida (the "Panhandle" area) I've seen roadside signs every mile or
so indicating the local voice repeater frequency, very useful (pitty the
handheld I had wouldn't go outside our 2m band, or onto your 70cms band)
Again, many places elsewhere than the US, you need all sorts of
permissions to put up permanent signs, of any type, for whatever reason.

An excelent idea none the less...

Cheers..

Dave G0WBX.  Tin hat on, coat ready, engine running and the doors are
open....




> -----Original Message-----
> From: Robert Bruninga [mailto:bruninga at usna.edu] 
> Sent: Sunday, July 02, 2006 5:46 PM
> To: johnk.mchugh at att.net
> Cc: aprssig at lists.tapr.org
> Subject: [aprssig] Digis everywhere
> 
> As I visited the Airport today, I was reminded how APRS 
> groups need to work to serve the traveler.
> A small HT powered digi at each high density travel point 
> should be a goal of all APRS support groups.
> 
> Airports, National Parks, train stations etc anywhere where a 
> fellow HAM might arrive and want local info.
> 
> Under the new-N  paradigm, ANY old TNC will work.
> The digi serves two important functions:
> 1) It acts as a fill-in WIDE1-1 digi
> 2) It beacons every 5 or 10 minutes DIRECT showing the 
> travler what he needs to know in that
> area:
>   - Freq of best traverlers repeater that can be hit from the
>    location and/or
>   - freq of local ECHO or ILRP node
> 
> These allow a person with a D7 in their pocket, even indoors to:
> 1) See the digi's posit which he can copy as his
>     present location, (and add 1 mile ambiguity)
> 2) Send out any message or email back home
> 3) Know what voice frequency to monitor or call for local info
> 4) Know how to call back home with ECHO or IRLP
> 
> yet, being low power and probably at local height, their 
> fequent local direct packets will have no impact on the rest 
> of the local APRS activity.... yet provide a great service to 
> travelers.
> 
> ANy old TNC and old HT laying around could be used.
> 
> Bob, WB4APR
> 
> 
> 
>