Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Guerrilla Repeater
17 April 2014, 05:33, (This post was last modified: 17 April 2014, 05:58 by Lightspeed.)
#1
Guerrilla Repeater
Notice: Without an appropriate radio license, repeaters are illegal to deploy in the UK at the current time. The use of parrot repeaters on PMR and CB is a grey area. In theory if uplink and downlink are on the same frequency it does not infringe the license conditions. I have formally contacted Ofcom for clarification about this, but they have failed to respond. So in the absence of clarification assume current use to be illegal.

A 'guerrilla repeater' is a low powered repeater system using either a simplex (parrot) repeater box ( see video #2) connected to either a transceiver. The transceiver can be PMR, Ham, UV5R,CB, or anything else you wish. Configuring the system with a UV5r/PMR makes a very small bundle. Place this in a waterproof box, with a rechargeable battery and charge controller fed from a PV cell attached to the outside of the box to create a self-contained, self-powered unit that can be deployed onto the roof of a tower block, in a church tower, on a hill top etc etc.

Its guerrilla because deployment is clandestine and with out consent of anyone. Obviously the unit needs to be well hidden, but in direct sunlight in order to be stand alone functional but without attracting attention.

We use the Radio tone simplex repeater unit. This records audio from the transceiver, stores it for a short time and then retransmits it to the audio in(mike) connector of the transceiver, which re-transmits the message. Its known as a parrot repeater because it effectively parrots whatever it hears. Uplink and downlink can be on the same or differing frequencies. Indeed you could even uplink using a PMR and then downlink on CB if you wished…. But I can see no application for doing this.

It is possible to create a real-time repeater using back to back PMRs or any other hand held transmitters. I covered this in an earlier thread, video #3 is a good description of how to do this.

Privacy vs open access: A repeater can be set up with open access so that anyone at all can use it. This would be appropriate for a community communications project. It can also be set up for semi private use by employing wide spaced uplink and downlink frequencies and CTCSS/DCS coded transmissions. The Radio Tone Simplex unit is able to be turned on and off using DTMF codes sent from a remote transmitter, so can be activated and deactivated at will from a remote location.

Links:
Simplex repeater in operation ( London)
http://www.youtube.com/watch?v=VTRizAhBFuQ

Simplex repeater product and setup
http://www.youtube.com/watch?v=ANNCn3zXFQ0

A back to back real time repeater using two UV5rs
http://www.youtube.com/watch?v=_KrH86Dzhnc

Update

A bit of muddle-engineering for a waterproof repeater housing, made from a 1 gal paint tin

Neat idea, and easily painted for camo.

Using a metal tin means that an external antenna is needed though.

http://www.youtube.com/watch?v=REocFY78Pyg
72 de

Lightspeed
26-SUKer-17

26-TM-580


STATUS: Bugged-In at the Bug-Out
Reply
17 April 2014, 10:51,
#2
RE: Guerrilla Repeater
Would it be possible to make a birdbox style housing for it, and then forego the need for an external arial? So fit the solar panel on the roof, then just carefully play with everything else to have it inside the 'house'

If you drilled lots of holes, upward facing at 45 degrees, would that allow the signal, but not water, inside? Does that make sense?
Dissent is the highest form of Patriotism - Thomas Jefferson
Those who sacrifice freedom for security deserve neither - Benjamin Franklin
Reply
17 April 2014, 12:01,
#3
RE: Guerrilla Repeater
Is it legal LS, to use the 2x UV5R repeater system on business channels i have a licence for?

for evaluation purposes i could set up 2x UHF rx on 449.3125 and tx on 449.4750?

let me know what you think from a legal point of view.

its also worth mentioning we are the only business on these freqs in th area i am aware of.
in some cases, those with the least to say, say the most.....
Reply
17 April 2014, 17:05, (This post was last modified: 17 April 2014, 17:21 by Lightspeed.)
#4
RE: Guerrilla Repeater
Yep, do-able scythe

I'd try and find a thin plastic wood ( and non absorbant) to make it from.

To be pedantic try cooking some of said wod in a microwave. It it does not heat up it is non conductive and will be fine. It it gets warm / hot you'll either have to have external antenna or seek out an alternative material.

(17 April 2014, 12:01)Binnie Wrote: Is it legal LS, to use the 2x UV5R repeater system on business channels i have a licence for?

for evaluation purposes i could set up 2x UHF rx on 449.3125 and tx on 449.4750?

let me know what you think from a legal point of view.

its also worth mentioning we are the only business on these freqs in th area i am aware of.

Hi Binnie,

I'm not au-fait with the Private business license regulations.

You'll need to check out the small print for yourself.

the grey area that I'm trying to get resolved with Ofcom in the CB regulations is that it allows to record and play-back of transmitted signals. It also has the requirement that Receive RX and Transmit TX are always on the same frequency. This apparently implies that a Parrot repeater, receiving and then re-transmitting on the same frequency, is compliant with the regulations...... but to date Ofcom have not confirmed this.

I strongly suggest that you get an Ofcom agreement before proceeding as you could jeopardise your business license if you get it wrong.
72 de

Lightspeed
26-SUKer-17

26-TM-580


STATUS: Bugged-In at the Bug-Out
Reply
18 April 2014, 07:28, (This post was last modified: 18 April 2014, 07:40 by Binnie.)
#5
RE: Guerrilla Repeater
Thanks LS.

My other option is to set up a clandestine repeater somewhere rural thats not going to interfere with anything and use PMR freqs on 1W (yes naughty, but not risking business licence!)

also i see you get repeater boxes from ebay, about £50 and records up to 120secs of audio, then TX back on same freq,

dunno if they are any use though
in some cases, those with the least to say, say the most.....
Reply
18 April 2014, 10:31,
#6
RE: Guerrilla Repeater
Yep, a radio tone simplex ( parrot) will cost you less than £60

Hook that up to a PMR which is CTCSS/ DCS enabled, put these into an RF transparent waterproof enclosure, and you'll have a low cost and discreet test bed.
72 de

Lightspeed
26-SUKer-17

26-TM-580


STATUS: Bugged-In at the Bug-Out
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)