Wednesday 29 June 2011

Hiking and Amateur Radio

I am writing this after reading some emails received from a fellow Radio Amateur.

John ZS6AA and friends, are planning to undertake a 12 day hike in the Drakensberg. The question was, what would be the most appropriate communication medium to use.

APRS via VHF, amateur satellite, HF radio or sat phone?

IMHO

The APRS would be a novel and interesting option, but the chances are good that the coverage would be erratic and most likely be unavailable when needed most. The situation could be assisted by a well placed base station with a serviceable digi-peater and I-gate. On the plus side, it serves a locator beacon that could be used during an air/ground search.

The amateur satellites could work, but at this time we cannot rely on them in a life and death type situation. The FM easy satellites are not always available due to various problems being experienced at the moment.

I believe a low powered HF station on 40M would work very well indeed. A simple low dipole, that is easily erected would work fine. This should result in reliable communications from 400 to 800 km and from zero to 800 km (no skip), when the foF2 allows NVIS propagation.

I would recommend setting up daily schedules with 1 or 2 base stations, that in turn will keep track of the hiking group, their present position, their plans going forward and relaying any other info as required, including passing on weather forecasts that will affect the hikers.

This info can in turn be placed on a Blogsite or Facebook or some other facility, where the family and friends can follow and share their experience.

Sounds like fun…

3 comments:

  1. Post on behalf of Glynn:

    Hi Pierre

    I hope you are well.

    I actually posted a comment to your last topic “Hiking and Amateur Radio”, however, after posting it, it is not coming up . So not sure if there is a setting on the blog or my own error that caused the problem. However, I am going to write it below. I don’t want to re-type to the blog and lose yet again . You are welcome to put it on the blog.

    I have VHF APRS, however, over the weekend (Saturday I think it was), I was looking at www.aprs.fi and saw ZS1YT (Rassie) heading down the N12 towards Witbank. I originally thought it was a cellular APRS but soon realised it was HF when I hovered my mouse over the individual points and saw the path line heading to CT!!! At least I think it is HF.

    If you click on a dot, you will see is says via ZS1TX-4. Click that (http://aprs.fi/?call=ZS1TX-4) and you go to the gate which says “Cape Town HF APRS iGate 10.147.300”

    Basically, his APRS was beaconing over 1000+ km’s back to CT which was absolutely amazing!!! I have taken an image of his track from aprs.fi and placed it on Google earth and attached it.

    I do not know what radio, antenna and power he is using, but WOW. I certainly think I am going to investigate this as well.

    You can even see him moving around in Kruger. He is staying at Berg-en-Dal. I have also included a APRS.fi attachment for you as well.

    Keep well.

    Glynn



    Glynn Chamberlain

    Cell: - 072 119 0559
    Fax: - 086 730 3055
    e-mail: - glynsay@glynsay.co.za

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  2. Hi Glynn,

    I agree with you. Using HF APRS is quite interesting. It sure will be of great value during overland trips and trips into the more remote areas that we venture into from time to time.

    I monitored 10.147.300 MHz USB, but only heard an occasional burst of PACTOR on the frequency. I guess I was skip to Rassie in Kruger NP. Chris ZS1TX was digipeating almost every packet sent from Rassie during this time, quite impressive.

    I see APRS on HF is also using PSK31 and PSK63. Not sure how well it is supported. It might be a good alternative to 300 Baud Packet (AX25) ?
    http://wa8lmf.net/APRS_PSK63/index.htm

    I have been toying with the idea of using the GPS NMEA strings, extracting the salient bits of info and encoding it into CW (Morse) and sending it via a QRP HF (beacon) transmitter, this would make for a fun PIC project?

    Pierre

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  3. Hi guys,

    I did APRS while running in the Drakensburg near newcastle once. It was only effective when I was right on top of the mountain and in sight of the nearest VHF IGate.

    HF APRS could be effective on 30m (Tinytrak) , not to mention the FLDigi / PSKMail option which can also handle APRS. This option however needs a computer which can be difficult to carry and keep charged!

    73 Eddie ZS6BNE

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