GB3EN ATV Repeater

Location

GB3EN is located in Enfield, North London.

The site is at QTH locator IO91xp, NGR TQ328968, ITU region 1.

History

The GB3EN ATV Repeater became operational on 13 March 1999.
The first two-way contact through the repeater was between Les (G4GYP) in Cheshunt and Andrew (G8FSL) in Southgate.

For its first birthday, GB3EN was given a quick wash and brush up prior to the Picketts Lock Show.
Duncan G7VVF got to have a go on site with his new camera, hence the flashy pictures on this site.

In more recent years  DATV receive capability was added and in 2025 GB3EN was converted to digital output , it is now a full DATV repeater.
In 2026 70cm receive was added

Technical Details

Input 1249MHz FMTV
Input 1249MHz DATV 333kS/s 1000kS/s, 4000kS/s  MPEG2, H264, H265 auto FEC
Input 437MHz DATV 333kS/s, 1000kS/s  MPEG2, H264, H265 auto FEC
Output 1312Mhz DATV 1000kS/s - FEC 2/3 - H265

Theoretical coverage map

Pictures

These pictures are of the DATV gear now on site

Transmitter and PA

BATC Ryde 23cm Receiver
BATC Ryde 70cm Receiver
Analogue FMTV receiver
FMTV sync detector and switching

TX and RX Alford slot aerials and 70cm "Big Wheel" RX aerial and masthead preamp and filter

These pictures are from 2000 showing the original gear, with the transmitter constructed by Adrian G0OJY

The same site is home to GB3EN (23 cms ATV repeater), GB3LV (70 cms voice repeater)
 and GB3NL (2 metre voice repeater). Thus there are a few antennas on site:                        

The left hand mast carries the receive antenna for GB3EN at the top:

and the two transmit antennas lower down:

Two antennas are used to put a notch in the radiation pattern in the direction of Heathrow Airport.

The repeater itself looks like this:

and is a good signal in the equipment room:

GB3EN is run by The North London Television Group