Transparent RF Repeater

  • Thread starter guillaume hajek
  • Start date
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guillaume hajek

Guest
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 suggestions as where to find help for this?

Thanks!

Guillaume
 
On Monday, August 3, 2015 at 12:32:49 PM UTC-7, guillaume hajek wrote:

> 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 suggestions as where to find help for this?

It's not simple, you have to handle the inability to receive while transmitting. So, it
has to be arranged by store-and-forward of packets, with retransmission and acknowledgements.
Look at 'smart dust' efforts for inspiration...
 
On Mon, 03 Aug 2015 12:32:45 -0700, guillaume hajek wrote:

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 suggestions as where to find help for this?
Click to expand...

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
 
On 8/3/2015 3:32 PM, guillaume hajek wrote:
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 suggestions as where to find help for this?
Click to expand...

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
 
"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:55BFE5FE.5070605@electrooptical.net...
On 8/3/2015 3:32 PM, guillaume hajek wrote:
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 suggestions as where to find help for this?

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.
Click to expand...
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.

http://www.ebay.com/itm/SURECOM-SR-112-simplex-repeater-Controller-with-Kenwood-Radio-Cable-/291482453869?hash=item43ddb5476d
 
On 8/3/2015 6:28 PM, Ralph Mowery wrote:
"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:55BFE5FE.5070605@electrooptical.net...
On 8/3/2015 3:32 PM, guillaume hajek wrote:
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 suggestions as where to find help for this?

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.


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.
Click to expand...

I'm obviously out of date on that one.

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.
Click to expand...

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.
Already to go for about $ 76 from ebay.

http://www.ebay.com/itm/SURECOM-SR-112-simplex-repeater-Controller-with-Kenwood-Radio-Cable-/291482453869?hash=item43ddb5476d
Click to expand...

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
 
On Monday, August 3, 2015 at 8:32:49 PM UTC+1, guillaume hajek wrote:
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 suggestions as where to find help for this?

Thanks!

Guillaume
Click to expand...

Great thanks a lot for your help! If I were to store the signal before transmitting, the distance between the 2 antennas wouldn't really matter I guess? Maybe I could use just one antenna?
 
"guillaume hajek" <hajekg@gmail.com> wrote in message
news:7913a513-71ca-4c5c-a4de-f42786f2bfc8@googlegroups.com...
On Monday, August 3, 2015 at 8:32:49 PM UTC+1, guillaume hajek wrote:
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
suggestions as where to find help for this?

Thanks!

Guillaume

Great thanks a lot for your help! If I were to store the signal before
transmitting, the distance between the 2 >>antennas wouldn't really matter
I guess? Maybe I could use just one antenna?
Click to expand...

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.
 
On Tue, 4 Aug 2015 11:40:29 -0400, "Ralph Mowery"
<rmowery28146@earthlink.net> wrote:

"guillaume hajek" <hajekg@gmail.com> wrote in message
news:7913a513-71ca-4c5c-a4de-f42786f2bfc8@googlegroups.com...
On Monday, August 3, 2015 at 8:32:49 PM UTC+1, guillaume hajek wrote:
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
suggestions as where to find help for this?

Thanks!

Guillaume

Great thanks a lot for your help! If I were to store the signal before
transmitting, the distance between the 2 >>antennas wouldn't really matter
I guess? 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.
Click to expand...

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.
 
On Monday, August 3, 2015 at 8:32:49 PM UTC+1, guillaume hajek wrote:
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 suggestions as where to find help for this?

Thanks!

Guillaume
Click to expand...

Great thanks again for the help. Last question, does the incoming signal frequency matter? I realize the antenna has to be centered around a given frequency but as long as the antenna can pick it up, does the rest of the system 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
 
On Tue, 4 Aug 2015 13:04:44 -0700 (PDT), guillaume hajek
<hajekg@gmail.com> wrote:

On Monday, August 3, 2015 at 8:32:49 PM UTC+1, guillaume hajek wrote:
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 suggestions as where to find help for this?

Thanks!

Guillaume

Great thanks again for the help. Last question, does the incoming signal frequency matter? I realize the antenna has to be centered around a given frequency but as long as the antenna can pick it up, does the rest of the system 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
Click to expand...

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.
 
On Monday, August 3, 2015 at 8:32:49 PM UTC+1, guillaume hajek wrote:
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 suggestions as where to find help for this?

Thanks!

Guillaume
Click to expand...

Any advice on where to learn about those circuits? I did find schematics but I don't really understand everything. Any advice?
 
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