GB3FR is located in
the Lincolnshire Wolds, about four miles West of Spilsby, and
operates on channel R7; input frequency 145.175 and output
It can be accessed using ctcss (continuous tone controlled squelch
system). The ctcss frequency is in group B, (71.9Hz).
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 Tait base station and Marconi
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
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