Located on the borders of Chigwell in Hainault, GB7CH is A new multimode digital repeater for South Essex & East London


On air from 10th December 2020 the repeater, formerly installed at the Kelvedon Hatch Secret Nuclear Bunker, GB7KH, has been repurposed to provide digital communications using the top three most popular modes. DMR, Yaesu System Fusion and D-Star.
Location: JO01ao
Repeater Specifications:
TX frequency: 439.6125 MHz
RX frequency: 430.6125 MHz
Colour Code: 3
TX Power (PERP): 7 dBW
DMR
Network: Brandmeister
Repeater ID: 234112
Slot 1: Dynamic
Slot 2: Static
TG 23511 (LEFARS)
TG 235 (UK Call)
TG 2350 (UK Chat)
TG 2351 (UK Chat)
TG 2352 (UK Chat)
If using Dynamic Talk Groups on slot 1, when you finish your QSO, can you please key up TG 4000 to disconnect from the Talk Group. It will stop unnecessary activity on the repeater, the static talk group generate enough traffic as it is!
Please do not configure your radio for Dynamic Talk Group operation on Slot 2.
Yaesu Fusion
Network: FCS
Default Group: FCS00291 – CQ-UK-WiresX
D-Star
Default Reflector: REF001 C

The repeater is a homebrew affair originally built by George Smart M1GEO and installed as GB7KH at the Kelvedon Hatch Secret Nuclear Bunker.
It consists of two Motorola GM340 Transceivers being fed by a Zumspot Modem on an Arduino, controlled by Pi-Star on a Raspberry Pi. A ProComm Bandpass filter enables the single dipole array to be used for full duplex transmit & receive.
It is planned to replace the Arduino / Zumspot with an MMDVM Hat for the Pi which should cut down the switching time of the repeater and reduce the number of possible points of failure.

Want to see what going on? well here is the: Dashboard Link
V1.2 Oct 2021