Whilst on a walk around the Old Man of Coniston, Dow Crag and Walna Scar I had my FT1XD turned on with APRS enabled on the 2nd VFO 144.800. Most of the time it was using a Nagoya 771 whip, but whilst activating for SOTA G/LD-013 I connected it to a Spectrum Communications Slim-J mounted about 5 metres up on a SOTABeams Tactical Mast.
In total I have 60 entries in the APRS log on the handheld for yesterday. There doesn’t appear to be a way to download these (at least not according to a search of the SD-CARD or asking ChatGPT!)
I’m surprised because there are some distant stations logged. For example:
There was definitely a lift on 2m, but these distances seem impossible.
Maybe someone would be kind enough to educate me, if some of these are digipeated, how I would determine direct contacts?
The only way to know for sure is to examine the raw packet headers, but I don’t expect that your radio stores those.
However, looking at the beacon headers from those three stations on the APRS-IS:
2025-01-18 13:00:43 GMT: DB0SPB>APOT21,DB0PIB,WIDE1,DB0LOS,DB0TA,DB0ET,WIDE3*
2025-01-18 12:54:18 GMT: DF7IKM>TYQVR0,WIDE1-1,WIDE2-1,
2025-01-18 14:58:37 GMT: EI3JE-9>APAT51,EI2MGP-2*,WIDE2-1
they are all using multiple layers of digipeating, so you may have been hearing them third, fourth or even fifth-hand.
But I see that EI2MGP-2 digipeater is located 694m up a mountain, so it’s possible that you could have been picking up a relayed packet direct from there?
Is it a case of locating one of the contacts in my list that also has me?
I guess my other question is why am I getting pings from stations that aren’t directly connected? It doesn’t seem to make any sense to me. Maybe I need to review an APRS tutorial
Just to add, as a potential source of confusion, that I was using both the FT1XD and a LoRA tracker, and both had the APRS callsign set to M0NOM-7. I’ve just changed the FT1XD to M0NOM-8 so that next time I’m out presumabl they will show up as different trackables?
You may have received their signal but they haven’t received yours, or the packet was corrupted. Also, aprs.fi doesn’t show all the stations that received your spots - I think each spot is only shown once from whichever iGate was first to log it. Or it may even just be an arbitrary choice.
APRS can be awesome when there’s a lift. I’ve received packets from the Faroes, Germany, Netherlands, Belgium and France while out walking in the Cairngorms.
You’d have to be smart and arrange a QSO on a different frequency from 144.800Mhz to make it a valid SOTA QSO. One for my 2025 list, I think!
Makes it so much more likely to be a direct QSO and not not digipeated.
I thought you’d just missed how in the manual. I searched and skim-read the manual and now have a headache. And didn’t see if it was possible. It does seem to be a given that the software on high-spec handies is dire when it comes to the UI.
Yes that is the case, so you’re most likely to be spotted by the nearest station with the fastest internet connection.
Now if you want to eliminate the confusion of digipeaters, (and reduce the traffic of repeats on the channel) remove any references to “WIDE” in your beacon path, as I have with my LoRa tracker, and does the pico-balloon SP0LND-2, which was received over a range of nearly 500km yesterday afternoon by Peter’s iGate at Oswestry:
18/01/2025 13:29:43+00:00:SP0LND-2>APLAIR,NOHUB,qAO,G3SMT-10:!5459.19N/00313.37EO041/009/A=042208/P97S17O20F3N2 FT0 It was flying at about 13km over Dogger Bank at the time!
Yes. I just assumed there would be a folder on the SDCARD. There is also a 60 message limit, so I don’t actually know how many pings I got. Dire Wolf looks like it would be a good option to overcome these limitations but not sure if anyone has tried that portable, but then why would you when we now have LoRA solutions…
I had to drive from my QTH to Southport and back this evening so took the opportunity to test my 2-day-old LoRa APRS tracker (G8CPZ-7) using a car roof magmount antenna and my 4-day-old iGate (G8CPZ-10) via a V2000 collinear on my bungalow chimney, and to see what the coverage was like [excellent it turned out] and which iGates and digipeaters were involved.
Could someone confirm (or otherwise) that the number of packets count in the table of stations that rx’d me [see below] is the number they rx’d and passed on, either via RF (digipeater) or via the internet (iGate) and that it doesn’t show which iGate got there first. In other words, there are duplicates of the same packet.
Could one determine which iGate was the first to pass on to a server via the internet by inspecting the timestamps in the raw packets?
Anyway, I was impressed by the coverage over the entire journey [albeit this is not as testing as tracking a walker in, say, the Lake District dales]. Apparently many of my G8CPZ-7 tracker packets were picked up by the M0MZB-15 hilltop digipeater, which relayed them to my G8CPZ-10 iGate [which has a low-latency FTTP broadband connection] and often ‘beats’ other iGates to the server.
As someone very new to this game, I’m impressed by the flexibility and redundancy [hence resilience] of having a sufficient (but probably still not optimal) number of iGates and high-ASL digipeaters provides. We’re still to explore the coverage (and gaps) in the more testing central Lake district.
No, I think that shows a total of 256 unique packets received from you over the course of your journeys. The ones which are shown as direct reception by digipeaters have of course been subsequently iGated, but they are not double-counted.
Using the APRS.Fi portal, you can hover over each transmission and see its routing drawn in, for eample:
The potential for handies with digital capabilities such as APRS or digital modes like D-star or DMR etc. always ends up being nigh on impossible to use or leverage for enhancing the capabilities. I remember getting the chance to pick up a D-star handy in 2009 for a good price when in LA. But I soon found that it was impossible to connect to the 1200bps data stream the handy supported in parallel with the digital voice. It would have been wonderful if you could connect to and extract out the digital info then you could have had the ability to send digital messages (such as spots) from the handy into the D-star repeater network and then out over the internet. But no you couldn’t so I ended up writing the SMS spotting software instead of using amateur radio. And it was an utter pish 2m FM handy suffering from Baofeng levels of overload, cross-mod etc. It’s the same with all the digital handies, the manufacturers don’t seem to want to let us use the digital facilities for what we want. And now it looks impossible to extract the data from an APRS handy. It has to be a deliberate design decision to not allow you to access YOUR DATA! The only way round seems to be roll your own APRS TNC and use it with any old FM handy. Or APRSdroid or such. Kind of defeats spending serious money on an intergrated APRS handy.
And you’re right, LoRa looks to be able to blow traditional APRS away completely.
First: Sorry about piggybacking my topic on Mark’s @M0NOM APRS packet routing topic (it’s sort of related). I did a quick search for existing LoRa topics and from their titles they seemed to be more about building trackers or iGates. I probably should have created a new thread. But that’s spilled milk under the bridge.
Thanks Ross @G6GVI for the explanation. So, just to confirm my understanding: Of the 256 packets my tracker transmitted:
160 unique packets were received and passed to/registered by the APRS system via one of 7 iGates [This count doesn’t reflect that some of these packets were received by more than one station but their copies of the packet were ignored by the system having already received it by the fastest iGate].
96 unique packets were first received by one of 3 digipeaters and relayed by an iGate [the digipeater must tag the packet with its own ID I assume], and that digipeater/iGate combination was the only or the fastest connection to the server.
Someone let me know if my interpretation is wrong.
Once my tracker case kit arrives (hopefully, in the next few days) I look forward to assembling the tracker and heading into the Lake District hills - on foot next time - to see how it works (e,g routing, coverage) in that more RF-challenging environment.
Makes it so much more likely to be a direct QSO and not not digipeated.
