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DarkStar

Radio Direction Finding & Geocaching

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I'm looking at putting together a cache that requires using Radio Direction Finding to get to the final location, however I wanted to find out what fellow hams are doing?

 

I'm looking at using a BigRedBee BeeLine 16mw transmitter with a carefully disguised 1.5 watt solar panel to charge the battery so I don't have to swap it out every 3-4 days.

 

Any thoughts? Hopefully some people can post similar caches that I could use as an example. :o Thanks!

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I'm looking at putting together a cache that requires using Radio Direction Finding to get to the final location, however I wanted to find out what fellow hams are doing?

 

I'm looking at using a BigRedBee BeeLine 16mw transmitter with a carefully disguised 1.5 watt solar panel to charge the battery so I don't have to swap it out every 3-4 days.

 

Any thoughts? Hopefully some people can post similar caches that I could use as an example. :o Thanks!

 

I think this would be a lot of fun, however I would be really worried about leaving this type of equipment unattended..You could lose out on a lot of money,,,caan you say..MUGGLED?..or just out and out STOLEN.Like I said before I would love to find a cache like this,would really be lots of fun..just afraid it wouldnt stay put...good luck.

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I think this would be a lot of fun, however I would be really worried about leaving this type of equipment unattended..You could lose out on a lot of money,,,caan you say..MUGGLED?..or just out and out STOLEN.Like I said before I would love to find a cache like this,would really be lots of fun..just afraid it wouldnt stay put...good luck.

I agree that it wouldn't be very fun if it didn't last long. That's one of the primary reasons why I was looking at the cheaper BeeLine transmitter. Also, I would be placing it in a location that I would definitely be able to visit multiple times a week (I walk/bike to a transit station to get to work every day and it's by a nice cache-friendly area).

 

I guess another option would be to place the transmitter somewhere under my control with the final GPS coordinates transmitted in Morse code. I really like the idea of direction finding the cache a lot more though! :D

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Looks like a nice idea, however, a cache must be able to be searched by ALL. Using a radio directional aspect limits it to those having the proper radio equipment.

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Looks like a nice idea, however, a cache must be able to be searched by ALL. Using a radio directional aspect limits it to those having the proper radio equipment.

That's true, but you could use any police scanner or other receiver. You don't have to be licensed.

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Correct! A cache like the one I'm proposing would have a "special equipment" requirement, but would be available to everyone.

 

BTW, it is perfectly legal for anyone to own or receive with an amateur radio transceiver, however you just couldn't transmit without a valid amateur radio license. In this situation though, I would expect a lot of people to use a regular scanner to search for the cache.

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Correct! A cache like the one I'm proposing would have a "special equipment" requirement, but would be available to everyone.

 

BTW, it is perfectly legal for anyone to own or receive with an amateur radio transceiver, however you just couldn't transmit without a valid amateur radio license. In this situation though, I would expect a lot of people to use a regular scanner to search for the cache.

I agree. The problem is, what about the bomb squad? There have been so many stories of caches that have been blown up (one of my dad's included). Not to discourage you, but what would they think when they found this package? It's not like you could put it in the woods...

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I agree. The problem is, what about the bomb squad? There have been so many stories of caches that have been blown up (one of my dad's included). Not to discourage you, but what would they think when they found this package? It's not like you could put it in the woods...

Given that a cardboard box filled with garbage outside a dumpster was "blown up" recently in my area, I believe that proper labelling and landowner permission will help mitigate the risks. One option is, instead of trying to camouflage the cache, work with the landowner to make it look like as "official" as possible. One idea I had was to disguise it as a sprinkler control box, even with false controls showing if someone managed to open the lock without permission. But that's kinda why I made this post, as I wanted to see what others were doing...

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Sounds interesting. Thanks for including the link for the "Bee". I've heard about those, first time I 'saw' one. I'm curious what the current drain is. If your concerned about the hardware 'evaporating' on you, how about a simple crystal oscillator? A 'Fundamental Mode' Xtal osc at 16.28MHz will produce harmonics at 146.52MHz and 439.56MHz. A 48.84MHz '3rd Overtone' will do the same. a simple single transistor amp tuned to 2m with a simple coil and cap will still produce useable energy at 70cm. Since these would be low power enough to fall under Part 15, you do not need to 'ID'. International Crystal Mfg. used to sell kits for oscillators and simple amps. I dont know if they still do. The ARRL Handbook and several other books, Doug DeMaw's "QRP Handbook" is a good primer in low-power construction. Scale the critical parts to your band of interest.

The 'Super Cheap' option would be discarded 46/49MHz cordless phones. They 'include' all the parts you'll need, except a good antenna. RDF-Waypoints anyone?

Placement: I'm glad to see you are very intelligent and have given critical thought to 'politically correct' placement. Recently a well meaning, but not too bright geocacher decided to place his cache in an old ammo can. He then placed the can about 4ft up on a Stop sign, securely held in place with plenty of duct tape. In an industrial park near the guard shack of a 'high tech research facility' known for doing work for 'unknown' government agencies. What a Brilliant Idea!

Suggestion: Whatever you use for the container, circuit breaker box, etc. how about putting your callsign on it with the frequency and geocache ID#? (callsign optional) That way, the people looking for it will see that the frequency on their receiver is the same on the 'box'. Ordinary people will think it's just a industrial ID.

This is my third attempt to respond to your post. If it doesnt work, I give up. Anyone else having these problems?

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I agree. The problem is, what about the bomb squad? There have been so many stories of caches that have been blown up (one of my dad's included). Not to discourage you, but what would they think when they found this package? It's not like you could put it in the woods...

Given that a cardboard box filled with garbage outside a dumpster was "blown up" recently in my area, I believe that proper labelling and landowner permission will help mitigate the risks. One option is, instead of trying to camouflage the cache, work with the landowner to make it look like as "official" as possible. One idea I had was to disguise it as a sprinkler control box, even with false controls showing if someone managed to open the lock without permission. But that's kinda why I made this post, as I wanted to see what others were doing...

Labeling won't always work. We talked with a Geocacher who works with the local bomb squad and he said that even if a cache is labeled, they will still blow it up.

 

I would suggest that you put it in some kind of fake panel. I like the sprinkler control panel, but I would suggest that you use something like an alarm box that would partly explain the people with devices.

 

Good Luck!

 

73!

Mr.Moo

KI6ZON

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I'm new to geocaching, and on my first few runs, I also found myself wondering how radio could be incorporated into the hunt.

 

Understanding that not everyone is a ham, I was thinking that part 15 compliant devices operating in the range of common FM radio receivers would be viable. With their limited range, the clever placement of low power pulse beacons along a course may do well to direct a party from one place to another, without the need for specialized hardware or experience.

 

KE5VDY

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Hey Darkstar.

You are just up the road from me.

I am in Aloha and also a HAM for many years.

Love this idea. Would prefer a 2M signal tho.

Perhaps if transmitter was high in a tree and good camo it might be less likely to get Muggled.

Cache could be at base of tree or "5 paces North from tree" type info.

Thanks for the link to Bee products.

Good Luck and hope it works out. Will be looking for it.

Randy

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So wierd to hear that you get caches blown up... It like it's another world.

In Sweden I know of caches on motorwaybridges, outside policbuildings and so on and no one looks wierd at you while caching either (=

 

But I realy like the idea of this cache. Maybe hide the solarpanel abit up in a tree or something and then wires down to the transmitter or just place the transmitter out of reach for mugglers and bombsquad (=

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I'm looking at putting together a cache that requires using Radio Direction Finding to get to the final location, however I wanted to find out what fellow hams are doing?

 

I'm looking at using a BigRedBee BeeLine 16mw transmitter with a carefully disguised 1.5 watt solar panel to charge the battery so I don't have to swap it out every 3-4 days.

 

Any thoughts? Hopefully some people can post similar caches that I could use as an example. :D Thanks!

 

Why don't you just hide the cache and put the coordinates on APRS using your home rig?

:P

73's Daniel SWL NL13286

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