GB3FR is located in the Lincolnshire Wolds, about four miles West of Spilsby, and operates on channel R7; input frequency 145.175 and output frequency 145.775.
It may be accessed with either the conventional 1750 Hz toneburst, or by using  ctcss (continuous tone controlled squelch system). The ctcss frequency is in group B, (71.9Hz). 

The equipment in use consists of a Tait T355 receiver, and a T356 transmitter, with a logic control system designed and built by Derek G4SJV.  A Pye F494 is availiable as a standby.  Due to the rural location of the site, and the slightly unreliable electricity supply, a battery backup system is installed, conisting of two 42 AH dryfit batteries and a charger built by G4DDI. This system can run the repeater for approximately eight hours, battery operation is indicated by a "pip" every few seconds during operation.  Users are asked to keep use to a minimum when battery operation is indicated.

The aerial system consists of a J-Beam C5 colinear for receive, and a pair of dipoles for transmit. Isolation is provided by five Marconi cavity filters.

The equipment is located in a secure insulated temperature and humidity controlled hut within a farm building,

These pictures show the view from the GB3FR location, the aerial system and an inside view of the hut; visible are the Tait base station, the battery charger and the cavity filters.

A view of the aerial system