Guildford Repeater Group

Latest News


An additional user activated talkgroup is now available on GB7GF. This is talkgroup 2351 on timeslot 1. This talkgroup is linked to the UK Yaesu system fusion network. For more details see


Some small changes to the regional talkgroup structure will be implemented on the 7th May. The primary regional talkgroup for GB7GF will now be 801. All repeaters surrounding London will have this as their primary region. TG802 will still be available as a secondary channel on a user activated basis. TG803 will be discontinued as it will become redundant.

Additonal User activated UK wide talkgroups have been introduced. Talkgroups 80,81,82,83 and 84 are now available for longer QSOs.


After 1 year on the air GB7GF continues to work well. The UK DMR network has grown rapidly and some changes are now being made to allow further expansion. The changes involve re-organising and re-numbering the regional Talkgroups. See the Talkgroup information pages on this website for more details. Please also visit for the most up to date information.


Both repeaters continue to perform well. A receive pre-amp has been fitted to GB7GF and this has improved the sensitivity of the receiver. Work has started to build a filter/combiner unit which will hopefully allow us to run both repeaters on the main antenna. This will improve the coverage of GB7GF even further.

Several new 'User Activated' Talkgroups have been added to GB7GF. This is in line with the DMR-MARC policy and should help to reduce the number of repeaters involved in any QSO. See the repeater details page for more information.


The fault on the GB3GF transmitter has now been repaired and the repeater is back in service.


GB3GF is currently off the air due to a transmitter failure. It will be returned to service as soon as it can be repaired.

29/01/15 Progress report

GB7GF continues to work well with the coverage area matching that of GB3GF very closely. When the weather improves we will be experimenting with the antenna installation to see if the coverage can be further improved. Data usage on the Internet connection is lower than expected (about 100mb per week) which should result in lower running costs than predicted. However this will increase as DMR activity builds in the future.

Talkgroup Changes.......

Up to now the UK Wide Talkgroup 235 has been active on both timeslot 1 and timeslot 2 with TS2 being the primary and TS1 the secondary. With the increasing activity in the UK this has caused problems for local users of repeaters. If a worldwide QSO is active on TS1 and a UK Wide QSO is active on TS2 it effectively blocked all repeaters in the UK, even if they were not being used by either QSO. This meant that local users could not use 'their' local repeater. A strange situation.

The repeater keepers have been discussing this and have decided to remove the UK Wide Talkgroup 235 from Slot 2. This will then leave Slot 2 available for Local and Regional QSOs only. With Slot 1 being used for any UK Wide, Europe Wide and Worldwide QSOs.

TG235 S2 has not yet been deactivated but this will be done soon. After this has been done, if you call on this channel you will no longer be heard outside your local repeater. Please start to use TS1 for UK Wide calls.

The list of Talkgroups for GB7GF is now as follows.

Timeslot 1
TG1 Worldwide (any language)
TG2 Europe
TG13 Worldwide English
TG235 UK Wide
TG9 Local (secondary)

Timeslot 2
TG8 Regional (All repeaters in the London area)
TG9 Local (Primary)

It is still possible for TS2 on the repeater to be busy due to TG8 Regional traffic on other linked repeaters. This is considered acceptable as the increased coverage area thus achieved is one of the main benefits of the DMR network.

Talkgroup 9 remains available on both timeslots. Either (or both) may be used for local QSOs on GB7GF.

09/01/15 TG8 now working

The London and South East Regional Talkgroup TG8 is now working on GB7GF on TS2.
This Talkgroup links all repeaters in the south east of the country to effectively form one large area repeater. This should be ideal for anyone travelling in the region. It will also increase the chance of getting a contact when things are quiet on GB7GF.

Your radio may already have this talkgroup available, it may alternatively be called 'GF Regional' or 'GF Roaming' depending on how it has been programmed.

1/1/15 GB7GF Operational

The repeater was refitted to the site today and is now connected to the DMR-MARC Network. Currently active talkgroups are:-
Timeslot 1.... TG1 Worldwide, TG2 Europe, TG13 Worldwide English, TG235 UK(Secondary), TG9 Local (Secondary)
Timeslot 2.... TG235 UK (Primary), TG9 Local (Primary)

The regional TG8 is not yet working but will be added soon. This links all repeaters in London and SE England and will allow automatic roaming with suitable equipment.

31/12/14 Phew!

The problem with the Ethernet port was not as serious as it could have been. Just a partially unplugged ribbon cable inside the repeater. The internet connection is now working and the repeater will be returned to site tomorrow.

31/12/14 GB7GF off air

A visit was made to site today to enable the internet connection on GB7GF. However an unexpected problem was found in that the ethernet port on the repeater was not working. This has previously been bench tested without problems. The repeater has been removed from site for further investigation.

28/12/14 GB7GF First Switch on.

The remainder of the installation work was completed today, testing was done and GB7GF was switched on for the first time at 1300 local. The repeater is currently operating in local mode only with no internet connection. Please use Talkgroup 9 on Slot 2 for local calls. We are waiting for the network connection to be set up by the German Sysop. Once this has been done we will enable the internet link.

Initial testing shows that the repeater is operating as expected. Coverage appears to be very similar to that of GB3GF. Reports are welcome, please send to

24/12/14 Merry Christmas from Ofcom!

We have just received a very nice Christmas present from Ofcom. The licence NOV for GB7GF was issued on December the 17th and sent by Email on the following day. We weren't expecting this until the new year so it has caught us slightly unprepared. However work is now under way to get the repeater on the air as soon as possible. The antenna and cable have already been installed and the cabinet and power wiring should be completed next weekend. Then the repeater will be installed and tested. The exact date for first switch on is not yet certain and will depend on how the installation and testing progresses.

The Repeater details are as follows:-

Repeater Tx Frequency:- 439.6875 MHz (Your radio will need to receive on this frequency)
Repeater Rx Frequency:- 430.6875 MHz (Your radio will need to transmit on this frequency)
Colour Code:- 3
Timeslot 1 Talkgroups:- 1 , 2, 9, 13, 235
Timeslot 2 Talkgroups:- 8, 9, 235

01/12/14 Progress report

The application has now progressed to the next stage and has been sent to OFCOM to be passed on to the MOD.

At the recent GB3GF Group AGM funding for the DMR repeater was voted on and passed. To reduce the immediate cost to the group it was agreed that the group would pay one third of the cost. The remaining two thirds will be covered by loans from two members. The repeater will therefore be jointly owned by the group and the two members.

An additional saving has subsequently been made by purchasing a second hand Motorola DR3000 repeater. This has been fully tested and is now ready to be commissioned as soon as the licence NOV is issued. The 4G router has also been purchased to provide the internet connection.

03/11/14 Progress report

The application for GB7GF is progressing slowly through the system. It has been approved by the RSGB ETCC Committee and is now waiting to be sent to OFCOM. They then have to pass it on to the MOD for frequency clearance before issuing a Notice of Variation allowing the repeater to be used. The timescale for all of this is highly unpredictable but likely to be many months.

02/09/14 GB7GF Application.

We have recently submitted an application to the RSGB for an additional repeater to be located on the same site as GB3GF.
If this application is successful the callsign for this repeater will be GB7GF. This will be a 70cm digital voice repeater using the DMR mode.
The existing GB3GF analogue repeater will continue to be available as it has been for the past 34 years.

This will be a big project for the repeater group as the repeater itself is quite expensive and there will then be ongoing expenses to provide the internet connection. The means of funding this project will be discussed at the next repeater group meeting. If you wish to support us by joining the Guilford repeater group then please see this page.

DMR is a digital mode that uses time division multiple access to provide 2 time slots on a single carrier. This will allow two simultaneous conversations on the same frequency. As well as supporting local contacts the repeater will be linked to the DMR-MARC network using the internet to allow connection to other repeaters around the UK and the world. These repeaters are linked together in what are known as 'talkgroups', all repeaters in a particular talkgroup are linked together and you can select which talkgroup you want to use by selecting the correct 'channel' on your radio. At the moment the following talkgroups are expected to be available on GB7GF.

TG 9 GB7GF only
TG 8 All South East England DMR-MARC repeaters.
TG 235 All DMR-MARC repeaters in the UK.
TG 2 All DMR-MARC repeaters in Europe.
TG 13 All DMR-MARC repeaters in English speaking countries.
TG 1 All DMR-MARC repeaters in the world. (Worldwide calling channel. 2 minutes max)

Other Talkgroups may be added in the future.

DMR is not compatible with DSTAR or Fusion which are other digital voice modes currently used for repeaters. We have decided to go with DMR as it is the digital standard used by many commercial systems, this means that rigs are available from most of the main PMR radio suppliers and theses are already becoming available for good prices on the second hand market, much like the ex-PMR gear that fuelled the original amateur repeater development in the 1970s and 80s. Currently the 'big three' amateur manufacturers do not make a DMR rig aimed at the amateur market but both Kenwood and Vertex make commercial DMR rigs so the possibility is there.

For more information on the UK DMR network see or for more details on the Worldwide DMR-MARC network see

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