Simple APRS Question

[nuclearmonkey]

I have a simple question with a slightly elusive answer (to me anyways). I am just getting started with APRS on my vx-8gr. All is going well - i.e.. I have the list of stations received showing up no problem. I am not making it out, so I am guessing that I am a bit too far from the nearest digipeater to pick me up. The thing I don't understand is why I am picking up station beacons from over 200 miles away. One of them is an igate on aprs.fi that shows no hops whatsoever. I am trying to get a 'visual' understanding of what the parameters are for receiving beacons from other stations on my little HT inside my house. For what it's worth, if you look up Coral Gables FL on aprs.fi, you'll see the lone digipeater that's apparently just out of reach for me to make it out, as well as the not much else around here. Maybe someone can walk me thru this.

Thanks so much in advance!

 

[W5LZ]

I'm not familiar with your radio so you have to understand that. But, it it's receiving beacons then it's in range of those stations or a digipeater (A digipeater, or digital repeater, receives then re-sends a received signal like those beacons.) that's repeating those stations. Other wise, it wouldn't be receiving anything. That's understandable.
Now, as for sending a beacon or position report your radio has to first know where it it (GPS) or you have to tell it (program in your lat/long). Then it has to be programmed to transmit a beacon or position report, either when it moves or at some specified time interval, or 'on demand' (you tell it to). And that's where my not knowing anything about your radio makes me stop, I don't know if a VX-8GR is even capable of doing that, is it? If it is, then I have to assume that something isn't 'set' right.
The other part of it is that the typical 'rubberduck' antenna that comes with most HTs just isn't very good, or doesn't have much range if it's outside much less if it's inside.
- 'Doc

(FYI - 'apres.fi' is never 'real time', beacons/position reports are never up to date. How far they are from 'up-to-date' depends entirely on how busy the internet is, how long it takes to get a signal -to- 'aprs.fi'. That 'lag' can be from only minutes to as long as days.)

 

[nuclearmonkey]

Hi Doc, Thanks for the reply.

As for the HT, the gps is reading good. It's also sending out the beacon (it makes an audible at the set interval - in this case every 5 minutes - and shows the transmit light on when sending it. The antenna is a diamond SRH320A - a good antenna for a HT, but still just a HT sitting in my house. The closest digipeater to me seems to be about 5 miles away, I am guessing it's a bit too far to hear my HT, but similarly, it seems that my HT is hearing it just fine. I plan on driving closer to the digipeater and seeing if that rectifies the sending issue.

I guess my question is that I see a station's beacon pop up on the HT screen. When I look it up on APRS.fi, it's in Orlando (about 250 miles away). It shows no hops, as it is its own gateway online. So how am I seeing it? Why would the digipeater close to me be broadcasting it? And a bit more specifically, how - since on the APRS.fi site, it looks like the digipeater close by me actually routes back up to Ft Lauderdale to get an internet connection. Just trying to understand the process of the hops, and the criteria used to determine who gets which signals.

As something that seems designed to be more of a 'who's close by', it's a bit strange to see call signs from 300 miles out

Thanks so much!!.

 

[W5LZ]

Using 'aprs.fi' or any of the other internet related sites for APRS can be a bit confusing if you aren't careful. They are NOT fool proof by any means. One goof in the repeated signal and it can throw things off like you wouldn't believe. If you click the 'info' tab in the box when you click a station on 'aprs.fi' it will give you a summary of what it's heard in the last month. Do that clicking for a digipeater and see some of the 'distance' listings, they can be -very- optimistic at times. The local digi was listed in the Arctic for a while, for instance. Just a goof in the information getting to the internet.
If a beacon or transmission is received by a digipeater and the 'path' limits haven't been used up, that transmission will be repeated. That's what the 'path' statement is for, to limit how far it's repeated. A lot of times that 'path' is set too high, or a digipeater makes a mistake with it and it get's repeated (or dropped!) when it shouldn't be. Just a 'wrong' setting somewhere or a goof. That's just with RF repeating, not about 'igating' or what can happen if/when it hits the internet. That get's really odd at times too. There's one island off the west coast of Africa that seems to 'accumulate' all the goofs, sort of. Has to do with position reports that get messed up and reset to '0' longitude and '0' latitude. (I don't know if there's an island there or not, but that's where a lot of things 'default' to.)
I think if you get to within range of a digi or Igate your signal will eventually show up on 'apes.fi' (barring any goofs). Good luck with it.
- 'Doc

 

[nuclearmonkey]

Great reply! Little by little I'm actually starting to see the big picture. For a while, I thought it was lost cause. My main application for APRS is to have it set up in both my mobile, and my HT. Using a mapping software, keep track of fellow offroad / expedition trucks in a convoy, as well as be able to keep track of the HT when out on hikes away from the mobiles. The technology truly is fascinating, it's just a very steep learning curve to start off with.

Cheers!

 

[W5LZ]

Steep? Good grief yes. but certainly not impossible to climb.
I have an APRS transmitter set up in the car, it's always 'on'. I used to do a lot of tracking of where I drove, I did local deliveries. Figured if there was a problem of some kind I'd have something to show if I needed it. I also have the Delorme thingy that does it but wanted to 'build my own' sort of, kind'a. It does work. The 'APRSISCE32' software has turned out to be my favored one, I also have the 'UI-View' that I 'learned' with. You can 'save' the days activity with the 'APRSISCE32' thingy, never figured an easy way to do that with the '-View' program (just never learned). I've tried the TM-D710 in the car but a laptop makes things a huge lot easier. The '710 works, just not as large a screen and no maps, you know? I figure your radio does the same. Lot's of possibilities with APRS, just depends on what you want to do with it. I think it's fun.
- 'Doc

(The local club also does APRS in conjunction with weather spotting for the NWS. Being able to locate someone almost exactly makes a big difference with that.)

 

[hookedon6]

...I guess my question is that I see a station's beacon pop up on the HT screen. When I look it up on APRS.fi, it's in Orlando (about 250 miles away). It shows no hops,...

As something that seems designed to be more of a 'who's close by', it's a bit strange to see call signs from 300 miles out

Thanks so much!!.

because it is changing the SSID with each "hop"

gohere: APRS Paths And Digipeating 101

there is more current info avail on th web, but, this does show BOTH the "old" and "new" paragrams and pathways.

look at where he changed it from WIDE3-3 to TRACE3-3 .... the digi now shows the true ID of the repeating station

 

[KJ4VOV]

There's one island off the west coast of Africa that seems to 'accumulate' all the goofs, sort of. Has to do with position reports that get messed up and reset to '0' longitude and '0' latitude. (I don't know if there's an island there or not, but that's where a lot of things 'default' to.)

And Colonel Bleep is getting really tired of it too!

 

[nuclearmonkey]

because it is changing the SSID with each "hop"

gohere: APRS Paths And Digipeating 101

there is more current info avail on th web, but, this does show BOTH the "old" and "new" paragrams and pathways.

look at where he changed it from WIDE3-3 to TRACE3-3 .... the digi now shows the true ID of the repeating station

That link was great! So what I didn't realize was that each digipeater in 360 degrees is repeating. Now it makes sense why I'm getting Orlando - it doesn't take too many hops in my direction, and if someone has their number of hops set higher, makes even more sense. Thank you for posting that. I'm finally seeing the light at the end of the tunnel!