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How to make a DIY relatively long distance radio signal emitter/tracker? Answered

Hi,

This is a bit of a two-parter.

The first part is that I would like to make a DIY radio emitter that could transmit to a distance of 1km. I'm not sure about the laws in South Africa, but it should be legal if within the ranges prescribed by the law.

The second part is that I would like to create several devices that could track the nearest radio signal on a specific band or band range (as I would expect that I would have to use a filter for both the transmission and receiving). I think that direction of the source of the signal would be sufficient. 

The reason for this is that I have had a few instances over the years where people got lost while camping and had to sleep in the wilds because it was too dark to find their way back to camp.
Any advice, thoughts, links would be much appreciated.

Also, if you have any other ideas that will cost about the same or less, that would be awesome to try out, too :)

Best regards,

Vuur

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rickharris

Best Answer 3 years ago

Building radio transmitters is very difficult without some rather special test equipment, If you asking the question you more than likely don't have it.

There are so many issues you need to address, You can easily google a circuit, build it - getting it working well is a different matter. Most successful radios are very short range primarily because their aren't actually working very well.

1K isn't going to help someone that is lost they are likely to be further away then than. As said a GPS isn't costly these days and works really well in most areas, jungle, high rise areas and valleys being thee exception.

You can never compensate for foolish people who go into the wild ill equiped, with poor knowledge and badly prepared.

When I have been to SA I see most people carrying mobile phones seems a good way to get help.

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iceng

3 years ago

Join a fox and hound group in your area.

These people play a hide and seek type of game that try to locate the transmitting fox while the hounds track and triangulate the fox.

http://www.homingin.com/

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Downunder35miceng

Answer 3 years ago

LOL!
Loved that in my younger years.
We often had groups of 50 or more people and aim was always focussed on two things:
a) Showing off and teaching newbies how use directional antennas and RF meters.
b) Having a lot of fun and story telling about the day while the bbq is providing food for everyone.

Sign up at least two weeks before the start, provide a few bucks for the bbq and make sure to come back next time.
Too bad that this stuff is not as popular as it was back in my days, great way to have fun and meet new people.

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Downunder35m

3 years ago

Just by a scanner that covers the normal frequencies and is able to transmit with at least 0.5W...
No need to re-invent the wheel if everything you need is available for many years already.
And for getting lost someone launched satellites and invented the GPS ;)