Setting up APRS for Wheeling n' Stuff

nakman

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@DanInDenver I do remember that Black Bear incident... curious why you'd want to trade? what's the difference?
 

DaveInDenver

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I just don’t use it much at all. So if you had other merchandise, not a radio trade.
Kenwood seems to be having trouble making radios so that TM-D710 is getting hard to find. That could be a valuable barter.
 

nakman

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Ah, ok. yeah sure we can figure something out ;)
 

rover67

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Huge fan of my kenwood tm- v71a. That 710 i think is the same except the nicer face plate with GPS
 

satchel

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@DaveInDenver I wanted to try these Openadromaps out instead of the bbbike maps and they aren't rendering. I tried using some.of the xml renders as well and still didn't get it to work. Did you do anything other than download one of the v3 maps?

Yeah, I believe BBBike is producing maps using the v3 Mapsforge library. You have to watch this because the current Mapsforge library is v5 and won't display in APRSdroid. So compatibility depends on the source of the map.

FWIW, I use these maps: https://www.openandromaps.org/en

He still has archived the old v3 maps from 2019. These maps are nice because they have topo data beyond the basic OSM.
 

satchel

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Never mind, looks like my tablet is just a little on the slow side to render a map that large but it finally showed up.
 

nakman

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I ended up ordering an FTM-400, it should be here Friday. May take me a bit to install it, will take me a lot longer to learn how to use it, but rest assured I'll be asking for plenty of help. Still intrigued by this whole APRS thing.
 

CardinalFJ60

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I love mine. ask away....I need an excuse to get more familiar with the functions. I've gotten into many of them, but want to re-acquaint myself with Group Monitoring, group messaging, text messaging and stuff like that.
 

nakman

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So I just want to see where I am, and where you guys are, on a map somehow. And hit the Colorado Connection, and yak on simplex. I can do that now right?
 

RayRay27

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Is it possible to follow folks who use APRS with just the android app on a phone or tablet and not have a radio with APRS? I was just asking because I just bought a new Yaesu FT-3100 single band radio with no frills or thrills for just simplex communications but would be interested if I could still track folks with the application with APRS? Not sure if that makes sense?
 

satchel

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I use aprs.fi for this. If you pull up that map it will show you all the objects in the area and over time, or you can filter for exact call signs.

Is it possible to follow folks who use APRS with just the android app on a phone or tablet and not have a radio with APRS? I was just asking because I just bought a new Yaesu FT-3100 single band radio with no frills or thrills for just simplex communications but would be interested if I could still track folks with the application with APRS? Not sure if that makes sense?
 

nuclearlemon

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i've been having issues with aprs.fi and tracking fat bastard. originally, i was thinking it was an issue with aprs.fi, but now i'm thinking it might be my tiny tracker crapping out. is everyone else still getting good tracking info on aprs? mine is hit or miss on tracking....on a trip to new mexico, it got a five mile stretch outside of tres piedras and none of the rest of the trip that day. maybe i need to get my 710 pushing my signal and pull the tiny tracker out
 

satchel

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I haven't had any issues with my 710 pushing the data. Pretty much transmits with every turn.

I wanted to see what was available for a good value and performance tablet to run aprs and general multimedia stuff. Seems like the fire tablet 10 plus was the best I could find. Really responsive now that I've unlocked it and turned it into a standard android tablet without all the Amazon crap. Works great with my 710. Pretty good $120 spent.
 

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DaveInDenver

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Never mind, looks like my tablet is just a little on the slow side to render a map that large but it finally showed up.
Glad you got it working.

To answer your question for posterity - nope, nothing special. Just downloaded the ones I wanted and pointed my APRSdroid to the filename.map that I want to use.

One thing to realize is APRSdroid doesn't auto load the right map so if you click on a station and the screen remains white you might have to change to a different map. The station's coordinates are probably right but you don't have any information in your maps for it.

OpenAndroMap compiles maps using various state boundaries and in our case that means typically the Utah/Colorado map. But I often hear stations from New Mexico and sometimes Nevada and Arizona depending on the number of hops and what digipeater hear each other. I'd think it's common you guys would hear Wyoming stations. Those are different maps, so you might have to go into the preferences to point to a different one.

If you use the huge map Georg suggests this would not be a problem but that presents a couple of issues. One, it's a huge file and as slow as the pared down ones are that could be even slower. Also, that maps is now many years old so details and differences are starting to accumulate. As it is the last v3 OpenAndroMaps are now about 2 years old.

Oh, yeah, another thing to consider is some stations tack on erroneous coordinates or none at all. Common mistakes I've noticed are typos getting west-vs-east or positive-vs-negative on the longitude, which is most likely what happens if a station is sitting in Asia someplace. The spot exactly 180° from me is in northern China, near Yulin, Shaanxi, almost in Mongolia. Interesting tidbit about that, Yulin is a sister city of Gillette, WY.

Other times APRS objects or even stations won't have GPS data and will null the values, which give you coordinates of 0,0 and that position is off the west coast of Africa in the Gulf of Guinea. This is can be confusing even with a functioning map because it's just feature-less blue.
 

DaveInDenver

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Is it possible to follow folks who use APRS with just the android app on a phone or tablet and not have a radio with APRS? I was just asking because I just bought a new Yaesu FT-3100 single band radio with no frills or thrills for just simplex communications but would be interested if I could still track folks with the application with APRS? Not sure if that makes sense?
I use aprs.fi for this. If you pull up that map it will show you all the objects in the area and over time, or you can filter for exact call signs.
Yup, online APRS feeds are an option.

https://aprs.fi/
https://www.aprsdirect.com/

But as a network architecture APRS is intended primarily about over-the-air RF and hardware requirements, the Internet traffic runs in parallel and at a lower priority as it's not a core network function.

In fact the whole point of APRS is to be a data network that is fault tolerant independent of normal networks like the Internet primarily so that you can run without normal infrastructure, whether that's an emergency or just supporting a marathon where cell coverage is spotty.

Soooo.....
i've been having issues with aprs.fi and tracking fat bastard. originally, i was thinking it was an issue with aprs.fi, but now i'm thinking it might be my tiny tracker crapping out. is everyone else still getting good tracking info on aprs? mine is hit or miss on tracking....on a trip to new mexico, it got a five mile stretch outside of tres piedras and none of the rest of the trip that day. maybe i need to get my 710 pushing my signal and pull the tiny tracker out
Problems like this arise if you're using an Internet service such as aprs.fi as your primary display interface. All the stations will have had to traverse a lot more connections to show up on a map.

What TinyTracker and radio are you using?



Lots of technical stuff below...

If someone's technically curious APRS is essentially a Bell 202 AFSK X.25 packet switched network that functions like the telecom PTSN did, if you made it completely wireless, until about 25 or so years ago.

Like any communication network there's fundamental things that have to work. There's not tuning your modem for the correct levels, RF interference and packet collisions (more than one station talking at once) need to be addressed.

The most simple network is two vehicles talking. So you have data sources (e.g. GPS) or clients (APRSdroid) each talking directly to their TNC (semi-intelligent modem) and their radios over the air. This requires a fair amount of magic to happen but we're lucky that APRS is highly tolerant at 1200 baud so for the most part we can plug-and-go without much effort and have things at least sort of work.

So as not to rehash even more technical mumbo jumbo, these dudes have great analysis of Bell 202 and how it relates to drive levels, twist and time delay parameters in your configurations.

https://owenduffy.net/blog/?p=2035
https://www.febo.com/packet/layer-one/transmit.html

Beyond this mix in a digipeater and complexity increases. A digipeater is kind of like a repeater most people understand conceptually. They operate on a single frequency instead of two, which means they aren't as simple as connecting a receiver to a transmitter, though. They have to temporarily store the packet and re-transmit it a moment later.

But that's OK since a digi has to actually perform a little bit of processing anyway. They have to add their call sign to the packet (every station has to annouce itself and a digipeater is no different) and decrement the path counter (e.g. make WIDE2-2 into WIDE2-1) to decide if it should repeat or not (the number in the path variable tells a digipeater if it has anything to do).

It's not a great deal of processing so the hardware is very modest. It's not attempting to understand the whole packet. It's just reading and writing a handful of bits in the routing fields so turn-around delay is very short. It's probably already got the new packet ready to transmit as soon as you unkey the tail tone on your radio. So the total air time is nearly just twice your original packet length (e.g. the digi has consumed the least amount of air time theoretically possible).

Now to get the Internet (which is called APRS-IS, APRS-Internet System) you add to this network the concept of a gateways, which are a special client that fully decodes your APRS packets (which are formatted as AX.25, e.g. Amateur X.25) and reformats the data into IP (Internet Protocol) packets. It puts these newly made packets on the APRS-IS network where other applications such as aprs.fi can do their work with them.

Now this is already at least one layer of added complexity, thus decreased reliability. The problems that can occur are that a gateway doesn't hear you or not well enough to decode or it mangles the decode for whatever reason (collision, receive errors or packet formatting errors). A gateway can be more prone to missing packets than a simple digipeater, especially if the gateway is trying to act like a digipeater as well. Most high level digis don't attempt trying to be gateways and rather focus on turning around packets ASAP with minimal delay.

A gateway runs usually on a computer. It has to do all the radio and modem stuff like any other APRS station but also has to have an Ethernet or WiFi stack and do the actual packet translation. Any packets that might come in while the gateway is working will either have to be buffered and processed later or get ignored. So the total processing time is longer and it might not be ready to process a packet that is jammed too soon right in behind the one it's working on. If the gateway is using an old Raspberry Pi 2 it's going to be less responsive than a RPi4 or repurposed Windows/Linux/macOS computer.

And even if worked it still only maybe gets it to the Internet. The gateway had to work and have a good connection to its ISP before it goes to a core of APRS-IS servers that hold all APRS objects from every station on the planet. It could be thousands of updates every second. The APRS-IS servers are good at fault tolerance and load balancing and the admins are good at what they do.

http://aprs-is.net/

But it's all done by volunteers on donated equipment through ISP either donated or paid for by donations. So there is no guarantee of 100% reliability or uptime. I can't honestly say I've ever seen a problem that I could attribute to the APRS-IS itself but then again from the perspective of a user there's no way I could ever know 100% of my packets actually make it to the Internet either.

And consider that a gateway may be bidirectional, so it has to know when a packet intended for you shows up on APRS-IS. It then must process and transmit it. It only knows this if you have transmitted a position packet previously so now you have a geographic location tagged. This function is necessary otherwise whenever a message is sent it would be transmitted by all the thousands of gateways around the world, which is impossible. For this reason many gateways are one-way from RF-to-Internet only and won't listen for Internet-to-RF traffic at all. In totality a gateway might actually be doing a lot of tasks and like you know from your desktop or laptop the more applications you're running the more processor you need, risk of crashing or conflict (e.g. you get the equivalent of a spinning ball if the gateway is doing something else when you want it to get putting your position packet on APRS-IS).

If you missed one packet, the probability that it's due to an intermittent APRS-IS issue is small but plausible. OTOH, it's very safe to assume that if you miss more than one random packet or you see a repeatable pattern it's very likely not APRS-IS but either the gateway you're trying to use or the end client such as aprs.fi. And the website such as aprs.fi are also running on donated servers put together and maintained by a volunteer with a day job. They are not infallible. There again, though, if it's a random missed packet it's possible but if you can repeat the problem then it's almost definitely not on the aprs.fi or aprsdirect.com side.

Now if you're doing this afield with your cell phone your carrier will have had to put another bridge from the regular Internet to their cellular data network for IP traffic and you of course have to actually have decent enough cell service for it to work at all.

FWIW, this is why when asked I highly recommend that you do not rely solely on aprs.fi or other Internet service as your APRS client. If you want to really use APRS then figure out a way to talk directly to your TNC using a Win/Linux/macOS client (Pinpoint APRS, APRSIS32, YAAC, QTH app, etc) or APRSdroid for Android or the actual aprs.fi app for iOS (which does open a can of worms) for local (e.g. direct or digipeater'd) RF traffic. At the moment you can use serial-to-Bluetooth for Android device but if you have an iPhone you are basically limited to a Mobilinkd TNC3 and aprs.fi app (not the web, the actual app from the App Store). With a TM-D710 or TM-V71 you can dedicate one side to be a full time APRS radio. With the Yaesu radios only the FTM-350 and FTM-400 can operate fully independent APRS on one side.

None-the-less, to use cell-based aprs.fi it's a convoluted path. To hear an RF APRS station you have to have the initial packet transmit, be heard over the air by a gateway (with maybe a digipeater or two). That gateway has to correctly translate and send it on to APRS-IS, which then requires whatever Internet client to see it show up in the database and display it over a cell data connection.


Point being here is that hearing stations directly vs seeing them on APRS-IS at home on a browser vs on your cell phone using LTE is each a significant reduction in your chances for having a true picture of your local and regional networks.

Digipeaters and gateways only work as well as they can but if the signaling is too far off they can't work miracles. The high level digis are generally very good and are generally coordinated so that they work together. The lower level fill-in digipeaters people set up are a coin toss whether they help or hurt overall network throughput. But regardless going though a digipeater subjects your packet to collisions and the more hops you have increases the risk of a collision.

Now gateways can be sent up with almost no coordination, which means one might work excellently while another is dodgy. If you have a lot of them around the good ones will handle more traffic by their nature. If you don't have a ton then the reliability is completely dependent on how good it works and how well you've tuned your system. If for whatever reason they don't play nice then you simply get nothing showing up on APRS-IS even if it works locally with other stations or sounds OK on the air.
 
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DaveInDenver

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I ended up ordering an FTM-400, it should be here Friday. May take me a bit to install it, will take me a lot longer to learn how to use it, but rest assured I'll be asking for plenty of help. Still intrigued by this whole APRS thing.
Something that popped into my memory with these radios is to use external APRS you'll need a kind of unusual connector to get at the data lines - a 10-pin mini DIN.

Yeasu sells a few cables with a molded DIN 10 to D-SUB or standard 6-pin DIN like many radios use for data connectors. They also make a pigtail to bare wires if you want to make up your own.

Also realize that the APRS on the FTM-350 and FTM-400 is only partially implemented with respect to the APRSdroid discussion. Yaesu doesn't fully expose the TNC to the outside world (Kenwood gives you a full serial connection to the one in the TM-D710).

All the Yaesu does is parrot the heard stations out so you can display them. It doesn't produce heard messages on the data port nor does it let APRSdroid send a message you generate. All messages AFAIK have to be done through the radio control head.

One handy thing it does, though, is parrot all heard APRS stations as NMEA waypoints on the data port. This means you can in theory use any GPS receiver with a serial port to display them.

You don't really need to limit yourself to a phone/tablet, to dink with a USB OTG and USB-serial cable or Bluetooth adapter and APRSdroid at all if you just want to see other people showing up on a map. As long as your GPS device has a RS232 serial port the FTM-400 can feed it stations as waypoints for it to show you.

Some info on this:
https://www.4x4ham.com/showthread.php?8417-Finally-got-my-FTM-400DR-working-with-Android
https://www.4x4ham.com/showthread.php?4291-FTM-400DR-to-garmin

If you want a full APRS station with a FTM-400 you basically need to get a Mobilinkd or your particular other favorite TNC still and that ties up the radio no different than the ancient FT-8800 did since it can't auto switch from an external source. The Kenwood TM-V71 and TM-D710 are arguably better choices for doing voice and APRS in one box.
 
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