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APRS

Hi all

Some of you may have noticed that I’ve been playing with APRS while out activating summits in wales.

I’ve recently been using 30m while mobile travelling between hills and a VHF unit while climbing.

I know the coverage is very patchy in Wales (hence the use of 10 MHz mobile) but I was wondering whether my APRS beacon had been useful, helpful or interesting? Especially in giving a rough Idea where I am in relation to the summit to be activated?

Carolyn (G6WRW)

In reply to G6WRW:
Very interesting and useful Carolyn. Especially if followed on Streetview.
The path yesterday was going via GW4BVE and then an EI link.
Can you give details of what you are using?

Roger G4OWG

In reply to G6WRW:
GM Carolyn,
I enjoyed following your progress yesterday, both mobile and portable. Quite impressive results on 30M, not something I would have anticipated. What is needed is a VHF APRS node at the restaurant on Snowdon and route tracking in Wales would be a wonderful safety contribution. Thank’s for your efforts.
73 Frank

In reply to G6WRW:

where I am in relation to the summit to be activated?

Given adequate APRS coverage, it could certainly be useful. I caught Andrew (M6ADB) on G/SE-001 a few days back entirely because he’d mentioned APRS in his alert and I was able to see he was on station. It certainly helped that his APRS comment included a relevant frequency…

73, Rick

In reply to G3RMD:

The way to do it is to have a VHF/HF gateway in your car. That way you’re not dependent on the local (non-existent) VHF network. You only rely on HF>Net gateways in Europe somewhere.

I’ve thought about this lots and I reckon on about 75% of my walks I’m in easy range of the car on VHF. i.e. a modest antenna on the car and a modest antenna on the walker and a handy running a few watts. On many of the remaining ones, quite a few packets would get through though not all of them. From the car you have a pair of back to back TNCs (can be done with a PIC and an FSK chip rather than a Tiny2 etc.) that listens on VHF and talks on HF. Only needs to be one way, i.e. walker to HF, and as they say “my name’s Robert, I’m your father’s brother”!

You still need to carry something with you to connect the GPS to the walker’s handheld and send the packet but you’d need that anyway. If only there were enough hours in the day…

Andy
MM0FMF

In reply to G4OWG:

Hi Rodger

For VHF I have a Byonics AIO self contained GPSr/Tiny Track III/10W-ish 2m transmitter in a waterproof container which yesterday was being carried by John (BVE) as he has a 1/2 wave antenna on his rucksack.

John Had his 2m Yagi at home pointed towards where we were going to walk (knowing there is next to no coverage in Mid Wales) and was digipeating our APRS beacon. It just happened that the beam was pointing West and the first reliable Igate was in EI.

Carolyn

In reply to G6WRW:

Your use of HF APRS (10Mhz) whilst mobile in Wales worked well, it certainly gave chasers a good idea of your progress to the summitbase prior to your ascent.
Activators in West Wales are presently limited to the Irish digi on Mt.Leinster, which is only within range once the 1500ft mark is reached, together with any part time ones from the east ie(GW4BVE) which are set up on request.
Maybe in the future, some APRS Igate receive only stations could be set up in current 2m VHF repeater stations. (This set up would not interfere with any repeater operations and would deliver your track to the internet).

Keep up the good work Carolyn.

73 Robert G0PEB

In reply to MM0FMF:

Hi Andy

There is a far easier way to digipeat from VHF to HF than multiple TNCs, I’m not far from having it set up :o)

One of the reasons I’m experimenting with various bits of hardware/software and VHF/HF beacons. If it all comes together it will involve one transceiver in the van on one antenna and a single digipeater unit.

Carolyn

In reply to M6LEP:

Hi Rick

It’s not easy to add a message to the APRS units I’m using while out and about unless I carry a laptop with me :o)

But really I want to keep packet lengths as short as possible with the view of linking to HF; the shorter the data transmission the greater the possibility of being heard and linked to the net.

Carolyn

BTW

It is not too difficult to set up an Igate totally in software, no external hardware required.

I’m using at home the AGW Packet Engine to receive and decode packets (both VHF and HF) linked to UI View which will gate to the internet.

Carolyn

In reply to MM0FMF:

I need to get a round tuit before I play with APRS, but have you considered the effect on the car batteries of having this gear running during a long absence? Especially during cold weather?

73

Brian G8ADD

In reply to G8ADD:

Yes… :o)

My transceiver runs off a separate high capacity battery in my camper (there are two batteries with split charging) so no risk of getting back and not being able to get it started.

Carolyn

In reply to G8ADD:

I have the current budget for the gear…

2x PIC based APRS TNCs: 50mA
1x FT290 on RX: 125mA
1x Codan 8525B: TX (@100W PEP 11A)

I’ve got a 30Ah SLAB to power it. The magic comes from tweaking the TNC software so it only gates my call. If you do 300bps on VHF from the walker you could get away with simply using the squelch opening on the VHF RX to key the HF TX and feed the audio through. But that’s definitely bush league. Really you want to RX and decode on VHF, match the call and then queue up the posits so you only send the last posit received at 300bps FSK or PSK63 for HF every 10mins max. You’d send the last posit every 10mins regardless of how old it was.

The 30Ahr SLAB should last for several expeditions before needing recharging.

Andy
MM0FMF

Given adequate APRS coverage, it could certainly be useful. I caught
Andrew (M6ADB) on G/SE-001 a few days back entirely because he’d
mentioned APRS in his alert and I was able to see he was on station.
It certainly helped that his APRS comment included a relevant
frequency…

Thanks for the feedback… that’s the format I intend to adopt in future, so I’m glad you found it useful

It will be back on-air on Thursday from G/SE-004. Note to self… put the VX8DE on charge!

Andrew
M6ADB

In reply to G6WRW:

I find APRS very useful in this part of the world. And today just managed to get AGWPE working on my Desktop in conjuction with my FT-290R and APRSIS32 (by Lynn KJ4ERJ) running on 'puter. But I’m stuggling with the different deviation levels that Kenwood and Yaesu’s seem to put out (not helped by the pre-emphasis on the FT-290R).
I’m Rx only for now but hoping to go full RxTx later on.

73,
Colin

In reply to M6ADB:

It will be back on-air on Thursday from G/SE-004.

…and I can see you’re there now, but the bands have been wildly variable today and all I’m getting is static at the moment. Likewise for M0RCP/P on G/NP-001 on 40 metres. Earlier I did catch DG0JMB/P on DM/HE-020 after his signal went from about 31 to 59 in the space of about 15 seconds…

In reply to M6LEP:

It was a wierd afternoon…

An hour talking to myself (calling CQ SOTA G/SE-004 on 7, 14, 18 and 21m) with nothing, nada, zilch to show for it… I also tried calling into DL/OK1JRA/P on DM/BM-323 but couldn’t get a look-in

Then one call “CQ WFF GFF-120” and 50 contacts in the log in pronto time… lots of Russia, Balkan and Scandinavian contacts (including some SOTA chasers, eg HA7UG Laci)

But some of those contacts were very hard work, 33 then suddenly 59!

My first real pile-up… now I understand the real fun :slight_smile:

Andrew
M6ADB

In reply to M6ADB:

An hour talking to myself (calling CQ SOTA G/SE-004 on 7, 14, 18 and 21m) with nothing, nada, zilch to show for it…

Yeah, band conditions did seem weird today. I listend for you on the frequencies your APRS was showing, and on the one you had spotted, but it was rice krispies all the time.

Then one call “CQ WFF GFF-120” and 50 contacts in the log in pronto time…

Strange how it goes…

My first real pile-up… now I understand the real fun :slight_smile:

Sounds like it was a good trip, then. :slight_smile:

Well I now have a working mobile VHF to HF digipeater connected to one radio which will only digi my own call and position to 30m. The vehicle’s own position transmission can be disabled, if required, when away from the vehicle.

It was an interesting exercise to get it working but I am now wondering will I be able to use it within my license conditions.

It appears that you cannot leave an unattended transmitter away from your home location (for example at the base of a mountain), even if it cannot be operated remotely by anyone else, unless it is on 144.800 for less than 30 minutes. The relevant sections are Clause 10 and Schedule 2 of the amateur radio license.

I think the grey area is that the license allows remote operation (which is basically what is happening, although that is open to interpretation) apart from the 2m operation above. Another grey area is what distinguishes a personal remotely-linked radio system (in this case a digipeater which only repeats my data) from a beacon.

The question is… does anyone else interpret the UK licence conditions differently for a portable VHF unit being linked to a HF transmitter via packet and do you think it would be permissible?

Carolyn (G6WRW)

In reply to G6WRW:

The answer is Nike. Or Just Do It!

And not on 144.800 where the world and dog may be listening.

Andy
MM0FMF
(This is most definitely my own personal opinion and should not be construed as anything to with any role I have within SOTA)