GB7BK berkshire uhf dmr
amateur repeater
     
Channel DVU59
Transmit Frequency 439.7375
Receive Frequency 430.7375
Antenna Stacked Dipoles
ERP 14dBW (25W)
Access Method Colour Code 3
Basestation Motorola DR 3000
Coverage Click here to view predicted coverage (60k). Plots provided by the ETCC
GB7BK Talkgroups
(User Activated talkgroups are shown in red)
Timeslot Talkgroup Description
TG1 Worldwide. Use as a calling channel then use one of the user activated (UA) talkgroups (TG119 or TG129) to continue a contact.
TG119 & TG129 UA worldwide – use either of these to continue a contact.
TG13 Worldwide English speaking. Use as a calling channel then use one of the UA talkgroups, (TG113 or TG123) to continue a contact.
TG113 & TG123 UA English speaking worldwide – use either of these to continue a contact.
TG2 Europe. Use as a calling channel then use one of the UA talkgroups (TG119, TG129, TG113, TG123) as appropriate.
TG235 UK wide. Use as a calling channel then use one of the UA talkgroups (TG80, TG81, TG82, TG83 or TG84) to continue a contact.
TG80 - TG84 UK wide UA working channels. Use to continue a UK contact.
TG9 Local talkgroup (secondary). Use if TG9 Slot 2 is in use.
TG2351 UA talkgroup, which is linked to the CQ-UK talkroom used by the Fusion system.
   
TG801 UA Regional: South East England
TG810 Regional South West England
TG820 UA Regional: North West England
TG830 UA Regional: Midlands
TG840 UA Regional East of England
TG850 UA Regional: Scotland
TG860 UA Regional: North East England
TG870 UA Regional: Wales and Marches
TG880 UA Regional: Northern Ireland
TG9 Local talkgroup (primary)
TG9990 Echo server (to check your audio)

How GB7BK came about:-

In late 2013 the first DMR repeater in the south of the U.K. became operational, which was GB7NS at Caterham in Surrey. This could be worked from parts of Reading and the surrounding area. Some amateurs obtained DMR radios and the usage of DMR increased considerably throughout 2014. The number of DMR repeaters increased dramatically especially in the Kent, Essex and London area.

TVRG considered the possibility of putting on air a DMR repeater but decided to wait and see how the system evolved. At a meeting in January 2015 it was decided to put an application to OFCOM for a DMR repeater (GB7RU) located at a new site in Tilehurst, west Reading. This was to be co-sited with a new analogue 70cm repeater, GB3RU. In April we received the go ahead for GB3RU but learnt that GB7RU had be rejected because of the frequency requested. We then suggested other frequencies but these had to all be in the same DVU frequency band. Eventually we were told that the Primary User (MOD) would not permit any local frequencies to be used in the allocation used for U.K. DMR repeaters. This meant we had to look for a new site.

By far the most difficult part of putting any repeater on air is to find a suitable site at an affordable price. We also had to consider that the proposed site should be sufficiently far away from MOD sites otherwise the frequency would be rejected again. This ruled out all of the town of Reading and its suburbs. Any site to the East of Reading would overlap too much with GB7WL and GB7NS. We therefore considered the existing GB3RD site on the Berkshire Downs. This wasn’t ideal as it wouldn’t cover Reading that well and we wouldn’t be able to have a high antenna because the GB3RD antenna is mounted on a pole not a mast. There could be also problems with internet access from such a remote site, as proved to be the case.

However, we decided to go-ahead and put in the application to OFCOM. We changed the callsign from GB7RU (Reading UHF) to GB7BK (Berkshire) as this was more sensible for the site which is 11 miles away from Reading.

Approval was received and the repeater became operational in September 2015. Coverage was OK and more or less in line with predicted coverage map . We obtained internet access using a 3G wireless router but proved to be erratic and unsatisfactory. Subsequently, we have been given permission to use the site owner’s broadband which has improved matters considerably. However, it must be remembered that the site is fairly remote and outages occur from time to time.

Once again, a good source of further information is www.dmr-uk.net