APRS is supposed to be a two way system.

Sure, if all you have are local trackers sending posits out to I-gates, no matter how many I-gates, the anti-dup stuff at the server level should keep things neat. That's fine if it were a one way vehicle tracking system. APRS is a lot more than that.

What happens when that station sends a message to someone and receives an ACK, or if someone outside the local area sends a message/query to that mobile station? Every I-gate that has heard that mobile station dutifully passes that traffic from the APRS-IS to RF. IF you've "too many" I-gates in any local area, that traffic appearing at the same time can and will often kill itself. Result? You've turned your local RF network into an 'outgoing' only system.

It's encouraged that those gating traffic back to RF in an area coordinate their locations and output levels to avoid these on-the-air collisions.

Unless you plan on working APRS via satellite - no need to go 'right side up'. Invert mount on an aircraft makes all the sense in the world when using a terrestrial RF network. Only time it may be less than optimal is while on the ground.

But please - as I'm sure you already know - do limit your paths!! Even from a few hundred feet, it's very easy for a air-mobile tracker to saturate the APRS RF network.

Thanks!

Yes - it's possible.

But such functions are totally dependent on what equipment and software he's using. ie. If he has a KPC3+, check out the LLIST function.

I've no idea if UI-View has such a function or not.

ANN382 identifies the device that sent the original packet. Basically what WA6LSE is using. In this case he's using a Kantronics KPC3+ with the version 8.2 firmware. See http://aprs.org/tocalls.txt for the full list. It's handy to know what capabilities exist when replying or sending messages to that station.


WIDE2-2 is a 'generic, decrementing Unproto path'. That means any digipeater that responds to WIDEn-n digipeat request should digipeat that packet, but decrement the 2nd number by one. So, first digipeater that hears WIDE2-2 will digipeat that packet - but sends it on as WIDE2-1. Next digipeater hears it decrements it again - it goes out the 2nd digi as WIDE2 (-0 is assumed for all anyway, no need to type it). The 3rd digipeater hearing that packet will NOT digipeat it any further as there are no more 'hops' left in the path.


Tad trickier and I'm not as sure on this one. Looks to me like SSSYSP is in the 'To Call' position of the packet (my Xastir shows station info that way) - but it's not a 'valid' To Call (All valid APRS To Calls begin with A or AP). Ah Ha! This is a different station than your earlier example. Sneaky too in that you didn't include his call sign so we could look up his traffic. But, he is using a MIC-E encoded station. MIC-E uses the To Call slot as part of it's position report - I bet that SSSYSP is actually part of the position report itself. (could also be a tactical To Call so his packets go out via a specific digipeater. May be other options as well.)

Really - you should be asking these questions on the TAPR APRS SIG - that's where the best place for APRS questions really is. By comparison - this place is fairly dead.

Don't know about that particular product - but everything else I've ever used from Byonics has been exactly what I wanted.

Interesting - as the FCC has no jurisdiction over clubs, beyond issuing a club call sign - even that's done through the ARRL VEC, not direct with the FCC.

Incorporation is a State deal. If the club has any property or assets, worth exploring. Can also make liability insurance less of a challenge.

501(c)3 status is obtained through an application process with the IRS and is separate from incorporation - even if as a 'non-profit' group. Mostly it allows for accepting donations, and the donor being able to write that donation off their income taxes. If your club's annual income is below a certain level - also makes annual tax filings for the club a bit easier if you file via 'e-postcard'.

Take a look at Xastir. Curt - one of the lead developers - is very active in SAR activities. Xastir has several features built in just for SAR.

http://www.xastir.org

Xastir is also under active development - so if you've an idea, share it. Good ideas are rapidly included.

Oh SNAP!

CAT5 straight through couplers for about $0.90 each.
http://www.amazon.com/Ziotek-RJ45-Coupler-F-F-Straight/dp/B000BSLW8U

Drop a CAT5 patch cable in there and you're done.

I might still 'heat shrink' or tape the connectors - special for mobile use.

Uses RJ-45 connectors, right?

Pretty much any normal CAT5x patch cable should work - they're all 'straight throughs' (except the cross overs) - problem will be a 'female' end. For that, I'd use a 'keystone' punch block - the kind that will 'snap' into a wall plate. Pretty much any parts place will have them - special if they sell networking or telephone stuff. Shaque de Rathe's offering even includes a tool to push the wires into the slots (sort of a punch down). Home Depot, Menards and others have 'em on the shelves as well.

Patch cables are usually multi-strand conductors - takes repeated flexing well.

Slip some heat shrink on the cable first - may take a couple bits of various sizes to get a good fit - punch it down and then shrink up over the punched area. If heat shrink isn't in your "junque boxe"- just wrap well with a good quality black tape. Scotch 33 or the like. Voila - RJ-45 female on one end, RJ-45 male on the other.

If it gets funky for ya - holler. Something like that would literally take only a few minutes to assemble. Only 'problem' I might anticipate would be length limitations - any idea how long KW says this stuff can be run and still work?

I run APRS mobile as well as FM Voice mobile on 2m.
I use two separate transceivers. An HTX-242 and a TM-V7A, respectively.

I use two separate antennas, both NMO mounted on the roof of my vehicle - about 4' apart.

It works well - not ideal. I do get some desense on the voice side when the APRS tracker transmits - special if I have it on 'high' power. So, I run it 'low' (5 watts) and tolerate the occasional - rare interruptions. I'm SURE I get some APRS RX desense when I'm talking. But, but the nature of APRS, it's relatively tolerant of such things. After several years of such operation - both rigs work fine.

Under no circumstances should two transceivers be connected to the same antenna without appropriate design or protections in place (circulators, duplexors, switching, something!!) You run a VERY high risk of destroying a receiver.

Uh - yea.

Pretty much any of the APRS clients that do I-gate duties have a way to 'select' calls to be gated to RF. I know Xastir does - I think WinAPRS will do this as well and I bet UI-View does - but I don't know UI-View or WinAPRS. They run on the wrong platform for me. Too vulnerable to un-desirable actions to be left alone for too long.

wm7d.net allows wild cards. I've used both '*' and '?'

I assume you by a "SOFT search" you mean a search by your own software? Maybe take a look at how Xastir does it www.xastir.org - download the data from the FCC as a flat file, index it and go.

Richard,

Maps, how they look and all that totally depends on the application you use - not APRS itself. ARPS is the on air protocol.

If you want the widest possible variety of maps and display options, look at Xastir.

There used to be a page up with dozens of screen shots showing what Xastir can do. It was a VERY old version (1.0.x) and there has been a LOT of new stuff added (current is 1.9.4).

Check it out - I think you'll like it www.xastir.org

Well, you could start with the FCC database itself:
http://wireless.fcc.gov/uls/data/complete/l_amat.zip

From there, a bit of PHP would make look ups all but trivial.

Run a timed job to get the data file updated every night and you'd be in the 'big leagues'.

Canadian database is also available at:
http://205.236.99.41/%7Eindicatif/download/amateur.zip

(by the by - both URLs copied from the Xastir get-fcc-rac.pl tool)