GB7CL: DMR Repeater

On the 15th December 2015, the Martello Tower Group were issued with an NoV for GB7CL, a 70cms DMR repeater to be located at the Martello Tower alongside GB3TE.

Things moved quickly and on the 20th December, GB7CL went on test, attached to a dummy load in G0MBA’s workshop.  It remained there for a week before being moved to site and on Monday 28th December 2015, it was installed, connected to the internet and put on air.

On Wednesday 4th October 2017, GB7CL was moved to a new location near Thorpe-le-Soken.  This site is higher ASL than Clacton and is located roughly in the centre of our local area.  We hope that this location will allow good coverage throughout Clacton-on-Sea and the Tendring peninsula.  GB7CL is now a repeater that will cater for the local community.

On Sunday 24th June 2018 the aerial at the Thorpe site was raised by around 25ft and the coaxial cable replaced.  In theory this should only give a 3-5dB increase in signal but the practical effect is much higher as the aerial is now above any nearby obstructions with a much clearer view to the surrounding area.

On Saturday 9th March 2024 GB7CL was moved to the Holland-on-Sea site.

As of October 2019, GB7CL is configured as follows.

Always on

This means that if you’re tuned to GB7CL with Promiscuous or Digi Monitor turned on, you’ll hear anyone transmitting via any of these talkgroups.

(TS = Time Slot, TG = Talkgroup)
TS1 TG1 = World Wide calling channel
TS1 TG2 = Europe calling channel
TS1 TG13 = World Wide English speaking calling channel
TS1 TG235 = UK Wide calling channel
TS2 TG801 = South East England
TS2 TG840 = East of England
TS2 TG841 = “Special” talkgroup only available on GB7AL, GB7CL, GB7CT, GB7DS, GB7EB, GB7MK, GB7ND, GB7PP, GB7PT, GB7PY, GB7SE and GB7WS.
TS2 TG842 = “Special” talkgroup only available on GB3BZ, GB7AV, GB7CL and GB7EX

User Activated

These talkgroups will only be relayed if someone transmits to them and ‘activates’ them.  They will continue to relay for fifteen minutes and will then go silent unless the repeater receives another signal via RF.  As an example, you are listening to TG840 and someone says “Let’s QSY to TG83”.  If you want to keep listening to them, tune your radio TG83 and transmit briefly.  This will ‘activate’ the talkgroup on GB7CL.  If the QSO continues for longer than fifteen minutes, you’ll need to blip it to reactivate it.

(TS = Time Slot, TG = Talkgroup)
TS1 TG5 = Australia
TS1 TG80 = UK wide 1
TS1 TG81 = UK wide 2
TS1 TG82 = UK wide 3
TS1 TG83 = UK wide 4
TS1 TG84 = UK wide 5
TS1 TG113 = English World Wide UA1
TS1 TG119 = World Wide UA1
TS1 TG123 = English World Wide UA2
TS1 TG129 = World Wide UA2
TS1 TG2351 = YSF CQ-UK Wires-X link
TS1 TG2353 = Link to BrandMeister TG2353
TS2 TG810 = South West
TS2 TG820 = North West
TS2 TG830 = Midlands
TS2 TG850 = Scotland
TS2 TG860 = North East
TS2 TG870 = Wales
TS2 TG880 = Northern Ireland

In addition to these, there are two local talkgroups which are always on and are not connected to the internet at all. If you want to use GB7CL as a ‘local’ repeater then it’s recommended that you use one of these.

TS1 TG9 = Local chat (Secondary)
TS2 TG9 = Local chat (Primary)

Channel: DVU51
Output: 439.6375 MHz
Input: 430.6375 MHz
Colour code: 3
Location: TM218172 – JO01ot

You can see the Phoenix DMR Live Monitor for GB7CL here and the main DMR Repeater Status page is here.

Repeater upkeep

There is no official repeater group for our repeaters but if you would like to make a donation to the Martello Tower Group group to help fund the repeaters (we have a regular monthly cost for the internet services used by GB7CL and GB7TE) then we will be happy to accept it.

You can donate either via post to the repeater keeper:

Tony Horsman, G0MBA
12 Hanwell Close,
Essex.  CO16 7HF

Or you can donate via PayPal.  All contributions are gratefully received and will go towards the upkeep of the repeaters and other projects undertaken by the Martello Tower Group.  Donations are not used for special event stations and DXpeditions.

You can see a list of everyone who has donated to help support the Martello Tower Group by clicking here.