Mid Sussex Repeater Group

GB3HY is a 70cm amateur repeater located at Hayward’s Heath, West Sussex, operating on channel RB5 (RU250).  The unit provides excellent coverage of the central Mid-Sussex weald area, radiating from a 6dB gain omni-directional four-stack dipole aerial.

First commissioned in June 1989, the repeater has undergone a series of upgrades and modifications to bring it to its present-day condition.

History:                         First operational using Pye 460 series units
                                     Upgraded in October 1992 to Motorola MICOR units
                                     Recently upgraded to Tait T800 series units

Location:                       Princess Royal Hospital       QTHR: IO90WX
                                      Old Water Tower                   NGR: TQ339231
                                      Hayward’s Heath                  Latitude: 50.99173144°N, Longitude: 0.093448086°W
                                      West Sussex

Channel Frequencies: Transmitter output 433.125MHz     Receiver input 434.725MHz

Current Equipment:      RF rack comprising Tait T800 series units
                                     Single-aerial working
                                     Motorola four-cavity band pass-and-notch duplexer
                                     Logic based on 87C51 micro-controller designed and built by Paul, G0OJA
                                     Battery backup using two 12V 92Ahr batteries imminent
                                     Implementation of remote control and status-monitoring system in progress

Operating Parameters:    25W ERP
                                        25kHz channel spacing, 12.5kHz being considered
                                        Access by CTCSS only on 88.5Hz (code E)
                                        Time out period 5 minutes
                                        Call-sign and location text sent every 15 minutes when in beacon mode
                                        Call-sign text only sent every 15 minutes when in repeater mode
                                        End-of-over indicator text K, planned to be B when operating on battery backup

Organisation:                  Funded solely by donations from users
                                        Donations are welcome; please contact Gordon, G3XTH, g3xth@msars.org.uk

Engineering Team:        Repeater Keeper:                 Gordon, G3XTH
                                       Engineering Support:            Paul, G0OJA
                                                                                     Alan, G8YKV
                                                                                     Phil, M5BTB

Coverage map:

(click any of the images for a larger version)

Water Tower showing GB3HY Antenna System

Original Motorola system

On site testing of new Tait hardware

Pre testing of Tait gear part of the engineering team Gordon G3XTH and Phil M5BTB

Rear view showing Duplexer

New installation of Tait gear

Side view new Tait installation

Rear view showing Tait rack wiring and duplexer

Lower rear showing incoming supply meter