Hello,
I'm trying to build a transparent RF repeater (simplex) as a relay for two radios. The receive and transmit frequencies will be the same, I basically just want to receive the signal, amplify it and transmit it. Any suggestion s as where to find help for this?
Thanks!
Guillaume
There should be stuff in the amateur radio literature.
I'm not sure what you're thinking given your wording, but you most likely want to record the received baseband signal and repeat that, not what comes into the antenna.
There are amateur hand-held talkies that do this as an option.
-- www.wescottdesign.com
That's very difficult at RF, unless you use two antennas that are well isolated from each other. Otherwise it's like a PA system with the microphone too close to the speaker--all you get is feedback.
Amateur repeaters generally receive on one band and transmit on another.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
o radios. The receive and transmit frequencies will be the same, I basicall y just want to receive the signal, amplify it and transmit it. Any suggesti ons as where to find help for this?
It's not simple, you have to handle the inability to receive while transmit ting. So, it has to be arranged by store-and-forward of packets, with retransmission and acknowledgements. Look at 'smart dust' efforts for inspiration...
Amateur repeaters do not generally receive on one band and transmit on another. While they can, most of them are in the same band but offset by a standard ammount depending on the band. I have had a couple on the air for over 30 years.
It is easy to do what the OP wants to do. It is called a simplex repeater. One station transmits and the repeater stores the voice. When the station quits, the repeater transmits the stored speach. Not very efficent,but can and has been done.
Already to go for about $ 76 from ebay.
I'm obviously out of date on that one.
If there's a protocol like that, sure. But if you were doing it live, it would be incredibly annoying. Even a double-hop satellite link is disconcerting, and that's only a second or so round-trip delay.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
o radios. The receive and transmit frequencies will be the same, I basicall y just want to receive the signal, amplify it and transmit it. Any suggesti ons as where to find help for this?
Great thanks a lot for your help! If I were to store the signal before tran smitting, the distance between the 2 antennas wouldn't really matter I gues s? Maybe I could use just one antenna?
Thats right. If using the store and retransmit, then you could use a transceiver with a single antenna. It will be in the receive mode most of the time and store whatever is comming in for a period of time, Then it will retransmit. Sort of like a tape recorder is hooked up, records, rewinds and keys the trnsmitter and sends it out.
You might get improvements with two antennas if directionality is considered. ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
o radios. The receive and transmit frequencies will be the same, I basicall y just want to receive the signal, amplify it and transmit it. Any suggesti ons as where to find help for this?
Great thanks again for the help. Last question, does the incoming signal fr equency matter? I realize the antenna has to be centered around a given fre quency but as long as the antenna can pick it up, does the rest of the syst em have to be tailored to a narrow band or not necessarily? I'd like to be able to use the repeater for a variety frequencies
Depending on modulation type you may get into noise problems if you overdo the bandwidth. ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
o radios. The receive and transmit frequencies will be the same, I basicall y just want to receive the signal, amplify it and transmit it. Any suggesti ons as where to find help for this?
Any advice on where to learn about those circuits? I did find schematics bu t I don't really understand everything. Any advice?
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