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I want to make a FM radio transmitter, help me

CocaCola

Apr 7, 2012
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At 100mW and a 'hobbyist' level design you will likely only get about 1/2 mile of reliable operation, probably more so in the 100s of feet... There are always exceptions to the rule, but when you can pickup up a professionally designed radio collar for about $150 I can't see it really as 'profitable' and 'reliable' as you believe... Yes, the sum of the parts is substantially less, but there is more to a finished product than just the parts...
 
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Richard Muller

Oct 27, 2012
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I can appreciate that, but feel it would be a great project. If one of my dogs were stolen again I would have the knowledge to make another one instead of forking out another $150. I enjoy a challenge and this would be one. I am willing to build a new receiver if necessary. I am just trying to find an economic solution to my problem, and have a little fun building these circuits.
 

CocaCola

Apr 7, 2012
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Here is the basics of it...

http://www.radio-circuits.com/dpt.htm

Another option that you might consider is a pre-paid Android phone, just install a 'find my phone' app on the phone... Once that's installed with any other internet enabled device you will be able to get a GPS fix on the phone/dog... Basic lower end Android phones are pretty cheap nowadays...
 

Richard Muller

Oct 27, 2012
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Thanks for the link I think with a little modification one of those circuits should work. I think all I would need to do is remove the mic part and retro a pulse circuit maybe using a 555 timer. What do you think?
 

CocaCola

Apr 7, 2012
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That would be the basics of it, if you just want a click or beep... Or you could put a digital voice recorder chip there and make a custom tone or signal...
 

donkey

Feb 26, 2011
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richard as a favour to me can you tell me how the wholse setup works? we had another post ages ago in relation to this and I am very interested.
also thanks for the name change
 

Richard Muller

Oct 27, 2012
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Well if you mean raccoon hunting with dog and radio collars, here we go. I get to my hunting spot, and put the radio collars on my dogs. Then I let them loose in the woods so they can track and tree the raccoons. In the "professional"collars is a tip switch which will increase the beeping of the collar, it lets me know they have a raccoon up in a tree. I use the receiver to get a general direction and start towards it. The receiver I have has two channels so I can actually get location on both dogs. Once I get with in .5 miles of the dogs I switch the receiver into near mode this allows me to track at a closer range without adjusting the gain. The "professional collars have a line of sight range around 8 miles, but in the woods it is greatly reduced maybe 600 yards. They work fairly well as long as people do not take your dog and high tail it out of there. The frequency of these collars and receivers at least in the US is 216Mhz-220Mhz. My system runs on 2 channels as I have said 216.300 & 216.450.
I hope this helps shed a little light on how I use these units. Any questions don't hesitate because honestly tracking is alot of the fun. That and knowing you trained these dogs to do a job and they love doing it.
 
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