SpudFiles

A lot of ideas for tracking ammo have been discussed but this thread is to post links for for RF transmitters and receivers that are for DIY.

While drawing a schematic for MrC; I discovered some of these links:

http://www.instructables.com/id/433-MHz ... 3/YouTube/

http://www.picaxe.orconhosting.net.nz/433RX.htm

http://www.nr6ca.org/70cmyagi.html

http://www.picaxeforum.co.uk/showthread ... -Australia

Hmm interesting. I recognise the components from the second link, the receiver and transmitter is sold by a store in my city for $15 each I think.

Just a side note, the guy who made the one in the first two links is a Kiwi

Interesting thread!

I'm working with a research group at school to develop an affordable communication setup for a LEO cube satellite. We get a little more area to work with but if you scale our project down, and the ~50mile it must transmit it is a very similar scenario.

I've always thought that utilizing a small CR123A cell, or an 18650 and then having a PCB made in a fitting fashion you could fairly easily make something along the lines of communicating for our distances (3-5 miles MAX). albeit being sputnik like in it's transmission, this shouldn't be too hard. You would obviously benefit from working with a slightly larger platform than the "mini-boy" though - but where's the fun in designing the projectile around your problem? lol

Another idea would be to measure the RF Doppler shift from the transmitter (projectile) similar to a speed gun and then calculate your distance by when it's signal resumes normal transmitting frequency. If you wanted to be fancy you could even plot the speed accordingly to the Doppler shift - since you'd pretty much have to know this anyway to get the distance.

Luckily all we have to do is talk to and receive data packets from the damn cube sat Hopefully some ideas to get the creative input flowing.

MrCrowley wrote:Hmm interesting. I recognise the components from the second link, the receiver and transmitter is sold by a store in my city for $15 each I think.

Just a side note, the guy who made the one in the first two links is a Kiwi

I picked these links due to the close proximty of your location.
It is not just a coincidence.

I will post the preliminary schematics later.

FYI, Narrowband has better distance than wideband. A narrow band receiver lets the signal in while keeping the noise out resulting in high sensitivity to weak signals. A sensitive receiver is a must for low power location. A frequency stable transmitter and receiver is needed to keep the signal inside the receiver bandwidth. A high gain directional antenna on the receiver is good to have. A narrow band Yagi antenna cut to the frequency of operation can provide some good range.