Tracking transmitter, small but grunty - Electronic Circuits Projects Diagrams Free

Gaskell · 19th January 2007, 08:29 PM

OK now first off I know these circuits are all over the net and this forum BUT I'm after a small sized circuit with REALLY good range (I know thats like askin for a cheap to run V12 dodge viper!). The most important thing is the range here, Like 100 metres isn't gonna cut the mustard here and most of these circuits have a range of less than 100 metres. I did find what I'm after (better than I hoped for) but it was about $2200 US.

Ok so a little more specific here for you guys.
Range hoped for: about 1Km would be sweet
Size: naturally dependant on range and battery size but no bigger than about coffee cup sized
Output: just a beep or click maybe at 1 second intervals (longer wait between beeps/clicks should improve battery life.

So heres the nice little challenge for whoever can step up here. I'm open to different types (does not have to be restricted to FM signal).

A big THANKYOU to whoever can help with this.

stevez · 19th January 2007, 08:55 PM

A small handheld amateur transceiver can be had in that size. You must be licensed to use it and there must be proper control. The tranceiver I describe can be had new for about $150 US. A second small receiver could be use for control. If you do go the amateur radio route and are licensed you'll realize that you'll need to operate within those guidelines. In the US that means the transmitter must be "in control" - that control can be remote (via radio) but it must be controllable and monitored by someone. That which is transmitted cannot be for commercial use - strictly personal/hobby.

stevez · 19th January 2007, 08:56 PM

An afterthought - you and other members are likely to get more useful advice if you'd indicate your location.

Gaskell · 20th January 2007, 12:47 AM

I'm thinking more along the lines of a dog tracking collar or similar, just sends outs beeps or clicks to locate. It would need to be small enough to not be and issue either weight or size wise but with a good range.

BTW I'm in NZ, I'll update my profile now.

Sceadwian · 20th January 2007, 01:03 AM

The problem is anything that has a range like that is going to be transmitting at illegal power levels. As it's just a tracker signal simple AM bursts is probably the simplest method. Perhaps a shielded spark gap type transmitter using a capacitor and inductor to chose the oscilating frequency. You can't get much simpler than that.

Gaskell · 20th January 2007, 08:57 AM

hmmm, yea I'm unsure of the law in NZ when it comes to that but I know a mate has tracking collars on his hunting dogs with a range of about 2Km, the collars cost him a packet. He's in a wheelchair so keeping up with his hunting dogs is out of the question and sometimes they can chase stuff for miles. So he tracks them with the collars (the reciever unit came with 2 collars and is specifically for them). I think for what I'm after 1Km would be plenty.

A couple of questions:
What is the legal limit on transmitting power levels?
Is there going to be a difference in range (for a above level) between FM, AM or GPS?

Hmmm, this seems to be a bit harder and complicated than I thought. I definetly don't want to break any laws or interfere with anything (like radio stations) that could cause problems to anyone. I'll see what info I can find in NZ law for transmission power levels.

Sceadwian · 20th January 2007, 04:01 PM

The point is your mate bought those devices, that makes them legal, they used aproved frequenies and power output levels, and were likley tested by a local regulating commision, even makeing a home made device that does the exact same thing as that is going to be technically illegal unless you have an amateur radio license. You would however have to check NZ law as you said.

Gaskell · 22nd January 2007, 07:43 PM

I found this link about power levels, frequencies etc. According to this I can use certain frequencies at certain levels without a licence. Can I get the range I require within these limits?

BTW I'm sure I posted this message yesterday but it seems to have vanished.

Sceadwian · 23rd January 2007, 01:24 AM

The 26.95-27.3 or 40.66-40.7MHZ band seems like the best bet. They're low frequency so it's easier to build a circuit that uses those frequencies. Those could actually be generated directly with a crystal oscilator without a lot of complexity and they allow 1 watt max, which should get you a few km's line of site and be relativly reliable within 1km with obsticals.

Gaskell · 23rd January 2007, 08:40 PM

OK that sounds perfect, now the question. How do I get a diagram and parts list to build the thing? Hopefully someone here can give me a hand in designing the circuit for me. I can just cruise into DSE to get all the components and board to build a working model. If all goes to plan I'll actually get a proper board designed and built, but for the first model I'll just use the some versa strip board.

**Nigel Goodwin** · 23rd January 2007, 08:53 PM

Don't you have little licence free walkie talkies there?, buy a pair of those!.

Shax · 23rd January 2007, 11:47 PM

Have you tried the tx modules from Radiometrix or Laipac?

I use these modules for tracking rockets to altitudes over 20,000 feet, and ground recovery ranges of over 5 miles...

I've attacked a foto of a prototype... This one runs on 433.94mhz, and using a 120 mah, 9.6v nimh stack runs for about 4 days... If I tweak the code in the pic, it'll run considerably longer.

Sceadwian · 24th January 2007, 12:47 AM

Actually tracking the transmitter is a different story unless you want to tack a GPS recevier onto it.

Shax · 24th January 2007, 10:16 AM

Quote:

Originally Posted by Sceadwian

Actually tracking the transmitter is a different story unless you want to tack a GPS recevier onto it.

Not strictly correct... We use a small Yagi-Uda antenna attached to a handheld scanner (with signal strength meter!!).... Triangulation on the transmitted signal works well, and is simple and reliable, especially at extended ranges where you couldn't get a decent lock on the GPS data..

RadioRon · 24th January 2007, 07:09 PM

Quote:

Originally Posted by Shax

Not strictly correct... We use a small Yagi-Uda antenna attached to a handheld scanner (with signal strength meter!!).... Triangulation on the transmitted signal works well, and is simple and reliable, especially at extended ranges where you couldn't get a decent lock on the GPS data..

Nice to see someone using the right name for that antenna. Poor old Uda seldom gets any credit for this thing.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Title	Starter	Forum	Replies	Latest
Very Small Transmitter	NextStarNexus@gmail.com	General Electronics Chat	38	2nd January 2008 07:41 PM
Attempting to make a Keyfob transmitter...	adamthole	Electronic Projects Design/Ideas/Reviews	7	25th November 2006 01:05 PM
1.5 Volt Tracking Transmitter	ElectroMaster	Electronic Projects	27	31st July 2006 03:21 PM
Using LEDs to show the direction of a tracking transmitter	Electric Rain	Electronic Projects Design/Ideas/Reviews	1	18th June 2004 12:09 PM
How To Make Very Small Transmitter ?	Bertone	General Electronics Chat	3	4th July 2003 06:58 AM

19th January 2007, 08:29 PM	(permalink)
Gaskell	Tracking transmitter, small but grunty OK now first off I know these circuits are all over the net and this forum BUT I'm after a small sized circuit with REALLY good range (I know thats like askin for a cheap to run V12 dodge viper!). The most important thing is the range here, Like 100 metres isn't gonna cut the mustard here and most of these circuits have a range of less than 100 metres. I did find what I'm after (better than I hoped for) but it was about $2200 US. Ok so a little more specific here for you guys. Range hoped for: about 1Km would be sweet Size: naturally dependant on range and battery size but no bigger than about coffee cup sized Output: just a beep or click maybe at 1 second intervals (longer wait between beeps/clicks should improve battery life. So heres the nice little challenge for whoever can step up here. I'm open to different types (does not have to be restricted to FM signal). A big THANKYOU to whoever can help with this.

19th January 2007, 08:55 PM	(permalink)
stevez	A small handheld amateur transceiver can be had in that size. You must be licensed to use it and there must be proper control. The tranceiver I describe can be had new for about $150 US. A second small receiver could be use for control. If you do go the amateur radio route and are licensed you'll realize that you'll need to operate within those guidelines. In the US that means the transmitter must be "in control" - that control can be remote (via radio) but it must be controllable and monitored by someone. That which is transmitted cannot be for commercial use - strictly personal/hobby. __________________ stevez

19th January 2007, 08:56 PM	(permalink)
stevez	An afterthought - you and other members are likely to get more useful advice if you'd indicate your location. __________________ stevez

20th January 2007, 12:47 AM	(permalink)
Gaskell	I'm thinking more along the lines of a dog tracking collar or similar, just sends outs beeps or clicks to locate. It would need to be small enough to not be and issue either weight or size wise but with a good range. BTW I'm in NZ, I'll update my profile now.

20th January 2007, 01:03 AM	(permalink)
Sceadwian	The problem is anything that has a range like that is going to be transmitting at illegal power levels. As it's just a tracker signal simple AM bursts is probably the simplest method. Perhaps a shielded spark gap type transmitter using a capacitor and inductor to chose the oscilating frequency. You can't get much simpler than that. __________________ "Because I be what I be. I would tell you what you want to know if I could, mum, but I be a cat, and no cat anywhere ever gave anyone a straight answer, har har."

20th January 2007, 08:57 AM	(permalink)
Gaskell	hmmm, yea I'm unsure of the law in NZ when it comes to that but I know a mate has tracking collars on his hunting dogs with a range of about 2Km, the collars cost him a packet. He's in a wheelchair so keeping up with his hunting dogs is out of the question and sometimes they can chase stuff for miles. So he tracks them with the collars (the reciever unit came with 2 collars and is specifically for them). I think for what I'm after 1Km would be plenty. A couple of questions: What is the legal limit on transmitting power levels? Is there going to be a difference in range (for a above level) between FM, AM or GPS? Hmmm, this seems to be a bit harder and complicated than I thought. I definetly don't want to break any laws or interfere with anything (like radio stations) that could cause problems to anyone. I'll see what info I can find in NZ law for transmission power levels.

20th January 2007, 04:01 PM	(permalink)
Sceadwian	The point is your mate bought those devices, that makes them legal, they used aproved frequenies and power output levels, and were likley tested by a local regulating commision, even makeing a home made device that does the exact same thing as that is going to be technically illegal unless you have an amateur radio license. You would however have to check NZ law as you said. __________________ "Because I be what I be. I would tell you what you want to know if I could, mum, but I be a cat, and no cat anywhere ever gave anyone a straight answer, har har."

22nd January 2007, 07:43 PM	(permalink)
Gaskell	I found this link about power levels, frequencies etc. According to this I can use certain frequencies at certain levels without a licence. Can I get the range I require within these limits? BTW I'm sure I posted this message yesterday but it seems to have vanished.

23rd January 2007, 01:24 AM	(permalink)
Sceadwian	The 26.95-27.3 or 40.66-40.7MHZ band seems like the best bet. They're low frequency so it's easier to build a circuit that uses those frequencies. Those could actually be generated directly with a crystal oscilator without a lot of complexity and they allow 1 watt max, which should get you a few km's line of site and be relativly reliable within 1km with obsticals. __________________ "Because I be what I be. I would tell you what you want to know if I could, mum, but I be a cat, and no cat anywhere ever gave anyone a straight answer, har har."

23rd January 2007, 08:40 PM	(permalink)
Gaskell	OK that sounds perfect, now the question. How do I get a diagram and parts list to build the thing? Hopefully someone here can give me a hand in designing the circuit for me. I can just cruise into DSE to get all the components and board to build a working model. If all goes to plan I'll actually get a proper board designed and built, but for the first model I'll just use the some versa strip board.

23rd January 2007, 08:53 PM	(permalink)
Nigel Goodwin	Don't you have little licence free walkie talkies there?, buy a pair of those!. __________________ PIC programmer software, and PIC Tutorials at: http://www.winpicprog.co.uk

24th January 2007, 12:47 AM	(permalink)
Sceadwian	Actually tracking the transmitter is a different story unless you want to tack a GPS recevier onto it. __________________ "Because I be what I be. I would tell you what you want to know if I could, mum, but I be a cat, and no cat anywhere ever gave anyone a straight answer, har har."