Does anyone know of a simple plug and play locater beacon?
Ive tried looking into it but all I could find were random projects involving heavy reconstruction on walkietalkies\chip programming.
I would like to be able to find a downed craft even after its too late to go on audible (signal loss beepers) or visual (downlink GPS coordinates) indicators.

I was hoping to find some kind of "radio tag" thing they use to track animals and such,
but only triggered to transmit after X amount of seconds losing the RC signal,
so it wont interfere with normal radiotraffic.
A failsafe with a 555 timer for instance would do the trick.

http://fmtv.us/rf_beacon.html

Hey thats interesting!
So for around 75usd id have a tracker set, not as cheap as I thought but still interesting.

I wonder if I can use a button cell to let it last about a week (plenty of time id say),
and only let it activate once the RC receiver stops getting a signal.

Not only that, but it can me modified to be a UHF transmitter hooked up to a wii nunchuck for some long range flying. have a look at this thread:

http://www.rcgroups.com/forums/showt...php?p=14498006

Hahah thats so awesome its ridiculous.
Thanks lovegroove.

That last bit isn't plug and play but using it as a locater beacon it's ready straight out of the envelope.

just a thought, if you can support the weight
heres a completely plug n play system with gps
http://www.instamapper.com/diy.html
all u need is a $40 prepaid phone with gps built in
and it will cost u around $1 for a days use

remember if you have cell coverage, u'll find it

Moe

Originally Posted by lovegroove

http://fmtv.us/rf_beacon.html

Yes, the recipient is named " FMKIT ", who has an ID here on RCGroups.

Originally Posted by lovegroove

http://fmtv.us/rf_beacon.html

I picked up one of those beacons last summer and I love it. When I fly, I set it for one hour delay so it won't be transmitting to interfere with anything.

It's also fun when you go camping. We played hide-and-seek with it with my kids, where one person would hide it out in the forest and then everybody else had a walkie talkie and tried to be the first to locate it.

Another option is a falcon tracking unit. I don't know if it has delayed start or whether it can be set to start transmitting once you lose rc signal. It's a little more pricey because you have to buy their directional receiver unit, but you get longer range. I was thinking about getting one of those before I heard about fmkit's beacon.

Micro-Trak 300



coordinates can be read from a handheld unit or via the internet if your tx can hit a igate. http://www.openaprs.net/

I use this one http://com-spec.com/rcplane/index.html. Hit the "Products" Button.

The small transmitter is self contained the PT-1B is about 12 grams and it is in a waterproof, crash-proof case. The battery lasts for 30 days. No cell service needed. It will get out 1/2 mile in dense urban environments but I've picked it up at 3 miles from on top of a hill.

The larger transmitter, the AT2B really gets out. Probably 3 miles in Urban and 10 miles from a hilltop. It's a little heavier at about 26 grams. The battery last for 7 days.

The receiver PR-100 is a little pricey but it is very handy. There may be less expensive 1.25 meter receiver options with a DIY Yagi but I'm not familiar with any. The R-300 makes no sense as it only give you more available frequencies.

I have used the GSM pager before (ebay - $100)http://cgi.ebay.com/Smallest-Real-Ti...item1e5aadc03b but it's kind of heavy, 100 grams. It works absolutely GREAT, you just call it's phone number and it will text you it's GPS Location. You need to have a SIM card on board with GSM Cell service. You need available GSM Cell Service where you crash. It does not work if you crash it in the ocean, unfortunately that's what happened to mine and the salt water wrecked it.

I have ordered the FMKit beacon I just haven't received it yet. I will be interested to compare it to the Com-Spec setup.

There's nothing worse than loosing your plane and all it's electronics. Even when they crash and you pick up the pieces it's amazing how quickly you can rebuild. The one I lost in the ocean was the worst (just like not finding it) the only thing I salvaged was the GPS.

Happy Flying, Best to all

Steve

Originally Posted by stevekott

I have ordered the FMKit beacon I just haven't received it yet. I will be interested to compare it to the Com-Spec setup.

I hope you'll report your findings.

Ok here's what I found out.

My were in an tests were in a suburban environment with a lot of trees and houses.

My tests were on the Com-Spec low power unit and the FM Kit ELT.

Both units are about the same weight and the transmitters are roughly the same price.

The huge difference is you can receive the FMKit ELT with a relatively cheap Family radio receiver. The Com-Spec you need the Com Spec receiver or something receiving in the 1.25 Meter band.

Both transmitters seem to have about the same range, about .5 miles in a heavy suburban environment. Huge difference if you can gain some altitude. Find a Hilltop or a tall building to get an initial fix. I was able to get a signal out to about 3 miles from a 900' hill.

Hands down if you have the Com-Spec receiver it is a lot easier to locate your beacon. Two reasons. It has a built in very directional antenna and the transmitter puts out a ping about every second. It's very easy to adjust gain from far, near and close with a speaker, volume control and indicating needle.

The whole idea behind body blocking on the cheap FRS Radio was a real pain. Difficult to tell direction. Another problem with the FMKit ELT is that it only transmits at 25 second intervals. Trying to use the body blocking technique with such a long pause between signals is bothersome.

The reducing tones on the FMKit ELT does work nicely. At .5 miles you just hear the one tone. At 1/4 Mile you hear the two. 1/8 Mile you hear the three. and when you are real close you will hear all four.

I think you should forget about the body blocking technique and just drive 1/4 mile in one direction and see if you pick up any additional beep or loose the one you had. Perhaps a Yagi antenna would help greatly but then you are starting to add cost to the FRS Radio.

With the Com-Spec receiver finding the right direction is pretty easy just point and shoot. When the signal is really faint or if there is a lot of metal abound you may get a ghost image 180 degrees from the correct direction. With a little practice you can alternate between 0 and 180 degrees and tell which is the cleaner signal.

You can also use the BNC antenna connector on top of the Com-Spec receiver to use a different antenna. A yagi on a paint roller pole works nicely.

Another advantage of the Com-Spec beacon is it comes in a crash-proof, water-proof case containing the battery and it last for 1 month !! on a single CR2032. And they sell them for $ .50 each. With the FMKit you've got to figure out a case and battery.

If you can handle a little extra weight and cost the Com-Spec High Power Beacon is another option. It has probably 2 to 3 times the range, the battery lasts 7 days.

The thing about the Com-Spec receiver is it is part of your ground gear and you can't loose it. Although it's expensive it's a good piece of equipment. A couple guys could go in on one and that would greatly reduce the cost.

Both beacons have their advantages/disadvantages it's up to the individual pilot where they fit into the spectrum.

I've tried to be objective with my opinion and I hopes you guys out.

I haven't had to use it for real but now I'm flying with the Com-Spec because I've bought the bullet.

If you can't afford that option I would suggest the FMKit beacon. It may not be totally convenient but the difference between having it or nothing is huge !!

Best of luck, Happy Flying !!

Steve

wow! that thing looks like it escaped from 60's sci-fi movie!

couple weeks ago I dropped my low power nunchuck controller in knee deep grass , I went home to get scanner radio and could hear PPM from there. Back to fileld and realized that remote transmitting 10times stronger than beacon and body blocking did nothing to estimate direction even with antenna removed S-meter was at full most of the time, Nunchuck is pocket sized remote - not a plane! Even narrowing the area to 10x10meter was still too large area. Then I got an idea : I kept radio inches above the ground and it worked, signal was reduced, S-meter became useful , found the controller next minute. Keeping radio at ground level helped a lot, then I thought (but not tried yet) wrapping receiving radio in aluminum foil (kitchen ware) will do the same. Other day friend of mine hid postal envelope with beacon inside 1.5km away and I found it