Does anyone has ideas on homing beacon??

[ahmondjai]

I want to put it in my friend's car and track him down. :confused:

[probity]

<a href="http://www.google.com" target="_blank">http://www.google.com</a>

[PYRO500]

I believe this is a relevant topic, (it could be applied to pig's cars or armored cars etc.) the answer is not as simple as you would think. to track a moving vehicle that means you need a beacon transmitter to begin with. now the beacon transmitter can be easily powered from his bcar batery but needs some kind of properly tuned antenna unless you want a pathetic range. There are company's that sell beacon transmitters in the 400 Mhz range witch is what I would recomend. although sometimes in hilly areas and areas with lots of buildings the signal gets lost or weak this will give you the best power for your money, look for ATV beacons.

Now that you have your beacon transmitter you are going to need a way to hone in on it. There are two main ways of doing this. One is to use a direction fining antenna witch is simply a yagi element antenna (look that up on google) that has very powerful gain in one direction, ( dosen't have to be a yagi but they get the best performance at VHF) Another option is to get a doppler shift direction tracking system, what this is is a device that has 4 vertically polarized dipole antennas that are mounted on the four corners of your roof, these antennas are hooked up to a special direction finding device witch calulates doppler shifting of radiowaves into effect and uses the 4 antennas as refrence points.

Both systems can be fairly expensive for fun purposes but for serious use I'd recomend a doppler shift system. With 400 MHz atv your antennas could easily look like small cell phone antennas.

A good doppler shift system could cost you anywhere from 180-500$ depending on accuracy and reliability and wether it requires a scanner in adition to the antenna. A good high gain yagi antenna shouldn't cost more than 50 bucks but will require a scanner to listen in on the beacon. The beacon it self will run you anywhere from 80-150$ depending on the range you want and how you get it.

<small>[ September 03, 2002, 07:19 PM: Message edited by: PYRO500 ]</small>

[xoo1246]

Nowdays there are services called "friendfinder". Basicly it uses mobile phone stations to track a mobile phone with an accuracy of a few hundred meters. You can see the location from you laptop. This could be used if you wish to track someone at a large distance, and then use a another transmitter to close in the hundred meters you lack.

[rikkitikkitavi]

but it doesnt work every where and probably not so many companies provide it.

first idea coming into mind is a radio transmitter , but for that to work you need atleast two tracking stations to make an accurate triangulation.

if well wersed in electronics, connecting a cell phone with a GPS module could work. Additional microcompuing is neccessary of course.
Just ring it up and ask where it is! Problem is that unless you can buy a GPS module and GSM module(or substitute it with a small phone with data cable) it will be very bulky. Dont know if the GPS can recive the signal hidden in the car somewhere though.
GSM phones usually needs an external antenna too.

Most comercial tracking systems for taxis, ambulances e t c works this way, since it is very accurate (within meters for the GPS).
cheap and reliable technology.

/rickard

[PYRO500]

You do not need to triangulate all you need is a method of transprotation that you can ride around with your "tracker" and hone in on the signal by traveling in the direction your direction finding equipment is pointing.

[ahmondjai]

hum.....so, is there anything like when u come closer, a beeping sound or something like that will beep more frequently, something similar like the one in alien? when they tried to find the little gal? and most important, are there some cheap plans??

[Anthony]

yeah, you'll find them on the same site with the "plans" to make the C4 seen on Macgyver from common kitchen cleaning products!

[PYRO500]

No with this setup you do not get a faster and faster signal as you get close, you get a broader angle in witch the high gain antenna receves the signal. that aliens thing is holywood bullshit, the only way to get somethng like that would require alot of expensive electronics and wouldn't work to well especially at far ranges.

As for plans, I don't think your going to be able to build any direction finding high gain antenna that's compareable to a professional one, and it has to be matched to the frequency your using as well.

As for the recever, you really need the reception of a good super hetrodyne recever that has a BNC jack for hooking up your antenna, a good ,odern scanner (digital tuning not some analog piece of crap!)

Your transmitter shoud be VHF or UHF and should be anywhere from 500 mw to 3 watts depending on the range you need. The transmitter is one of the most important parts and needs to give out a reliable signal that is easily discriminated from radio noise.

[ahmondjai]

I have a idea, but it is going to work, don't know.
If I can hook something on to his car, with somekind of signal transmitting device so that i will know he's around me when i pass that area, and i m thinking something which will send out any signal for my scanner to pick up(like when i go near it, maybe it will send some white noise or anything, then, i can use my uhf scanner's signal strength meter to know where about it's from) , so, how's that? you guys think it's going to work???

[DeAd]

relating to that we play a game here with CB's. Its called foxhunt.Everyone has 23 or 40 channel cbs preferably with Rx signal strenth guage and rf gain dial - youll get best tracking ability with a 102 inch stainless steel whip ateanna mounted on the courner of your car. someone(the fox) will drive off anywhere in the city and sit and hide. every four minutes the fox will make a two minut Tx(our rules)usually some mundane events of the week.
the hunters wait for the Tx and then drive in small circles watching
the signal meater needle, when the opposite corner from the attena is pointed in the same direction as the fox you get a higher reading its easy to do with some pratice.
Cb's are cheep now cause of cell phones. so get the smallest one you can find radioshack has one 1 in by 2in by 4 in 29 $ also get the adaptor to use the auto's existing attena with the CB 19 $ . that would be your tracking transmitter. you could use different channels for different targets.
anyone hear of that game

[xoo1246]

I assume this is what you are looking for:
<a href="http://www.unikteknik.com/shop/shopdata/common_productimages/REDKNOWSRH10.gif" target="_blank">http://www.unikteknik.com/shop/shopdata/common_productimages/REDKNOWSRH10.gif</a>
You connect it to a mobile phone and GPS unit.
Dial it, it regonize your number, hang up and sends you the coordinates. Or it can be set to send you the position as it moves.

It costs around 300$

[krysthegreek]

What you might be looking for is something along the lines of an ELT (Emergency Locater Transmitter). It's a fairly small radio transmitter that transmits a warbling tone on a specific frequency only, typically used for crash site location for Search And Rescue teams. 121.5mHz for civilian aircraft, 243mHz for military aircraft, 121.6mHz [I]was[I] the frequency for boats, and 121.775 is used for training purposes. Many of these are being phased out by February of 2009 (in the US), and you should be able to find some of the older versions for fairly cheap ($200-35 USD). As far as detection equipment goes, L-Tronic makes some good equipment, and there are several plans to make your own (I apologize, I do not have any of these on hand, I will try to find some.), for less than $300 USD.

The largest downside of this is that the signal very easily reflects off of metallic, or even stone, concrete, etc., surfaces, making it difficult to track someone in an urban environment (though with practice it can still be done). Another downside is that with such a simplistic system, there is required a fair amount of practice/familiarity with the equipment and process; one cannot simply pick up the gear and be good at DF (direction-finding). The upside is that the equipment has been out there and tested for years, and should soon become even more available.

[Zait]

In the 7+ years that this thread has been dead I would hazard to guess that the OP probably either tracked down the friend or gave up due to the lack of technology.

While your idea is not bad it has the drawback of being somewhat expensive (along with all the other downsides you listed). It's probably far cheaper and easier to buy a GPS enabled cell phone, charge it (and maybe even add a slave battery or two) and use that to track someones vehicle.

[dinkydexy]

Even cheaper still would be to just find another girlfriend and get over it.

[mike-hunt]

There are child tracking services that work by mobile phone . You gust log onto a web site and view a map similar to a G.P.S and it shows the mobiles location. here is a UK Web site
http://www.childlocate.co.uk/
I have seen a similar one for Australia and remember thinking it would be a useful girlfriend tracker.

[DyD]

If you're looking for beacons - it may be best to hackjob a DIY beacon on an oft unused frequency. A GPS receiver could be attached to an Atmel micro-controller, which could in turn be attached to an RF modem. JFGI - there are a number of similar projects out there. If you're looking for something prebuilt, sparkfun.com sells a number of potentially useful GPS modules, including a complete tracking kit. Sparkfun's device is a GPS receiver attached to a GSM transmitter. They also offer a module that logs to text files on an SD chip. If you are able to pickup the device from the mark's vehicle, that may be an optimal approach.

[Mike123]

There is a schematic for a tracking beacon in More Electronic Gadgets For The Evil Genius if your into putting one together from scratch. This book can be found on any of the bittorrent sites. I put it together on a breadboard and it worked, although I never tested it over long distances.

[Bugger]

What would be the best radio locator beacon, if any, (together with a portable radio receiver tuned to its frequency), to put in a vehicle (including a motorcycle as well as a car) so as to enable it to be traced and recovered from the thief (with the aid of either the Pigs or private security "heavies") in the event of its being stolen? I had a motorcycle stolen two years ago, and although I have evidence strongly suggesting that a certain person stole it, the evidence it not strong enough for the Pigs to "bust" him and search his premises. The frequency band of the radio beacon, which would have to be turned on while the vehicle is left unguarded and not securely locked away, would have to be one that "carries" over a reasonably large distance (by diffraction and ionospheric reflection), because of the distance that a stolen vehicle might be driven away, so it would probably have to be in the short-wave region, either in the amateur and marine short-wave band of about 2 to 8 Mhz or the citizens' band of about 26 Mhz. Most short-wave radios can pick up these frequencies. Those frequencies for emergency locator beacons for aircraft and boats, in the VHF frequency range of about 120 to 400 Mhz (which overlaps with the FM and TV bands), mentioned above, would be traceable only over a few miles on the ground, or over longer distances only by search-and-rescue aircraft flying above radio-opaque obstacles, by line-of-sight.

[megalomania]

I still think for expediencies sake a throwaway cell phone with GPS tracker ability is a good bet. Your range on this is nationwide, more or less. The only big problem is limited battery life. Unless you can change the battery every few days, if you need a tracker to last longer, you will need to modify the power system. You could add a larger battery pack, but now you make it harder to disguise your handywork.

There are also dog tracking collars that use cell phne technology with GPS tracking. These presumably have much longer battery lives.

The best thing about GPS tracking is that you can get a "world line" of where the tracker has been than can be overlaid onto a map. You can see where the subject has been, what routes traveled, where the subject lingered... If it's an unruly woman you are after, it helps to know where she has been over time, not where she is at a specific moment.

[plutobound]

There are small trackers that use a combination of GPS and Cell Phone technology to enable them to work indoors as well as outside. Gives realtime tracking capability. If you don't need realtime, but just want to know where someone/thing has been, GPS data loggers are much cheaper and readily available.


http://www.brickhousesecurity.com/small-covert-gps-tracker.html

[Jacks Complete]

I'd opt for an infinity transmitter affair. Take a cheap cellphone, add a hands-free and set to auto-answer, then chop off the earbud so it is silent always. Charge that, add a SIM, then activate the e.g. Childtracker system fully, and then place it where you want it.

With the GPRS tracking data you will know where and when it goes (on grid, of course) and can also at any time simply place a call to it to listen in on what's happening.

The only issue would be the battery life, but that should be around 5 to 12 days, depending on how you use it. Far better than a regular RF bug, that's for sure.