G3TCT home ADF4351 exciter details
New PA

Current status

End April 2022 - the wind turbine which failed in Feb 2022 has been replaced and the new one is operational.

The beacon operates from IO81VC73 with beacon keeper G3TCT.  The NoV was issued by Ofcom on 20 June 2016. The beacon started operation on 26 July 2016.

Beacon parameters:-

Frequency 1296.870MHz.  The exciter is not GPS-locked.
As from 17 Feb 2017, the exciter is based on an Arduino-controlled ADF4351 synthesiser with a 10MHz reference and should  be within 100Hz.  For details see the link above.
Mode F1  (1K50F1AAN) with 400Hz shift
ERP 20dBW east and 16dBW north, horizontal polarisation
Antenna Wimo flat plate PA-23R-16.  Power is split between Wimo and 47cm dish pointing due north.  Maximum radiation from the system is at 090 degrees.
Height ASL 218m
Antenna height AGL 15m
Times of operation From 26 July 2016, 0600 to 2200UTC. 
From 17 Sep 2016, 0600 to 2000UTC. 
From 12 Oct 2016, 0800 to 1700UTC
From 20 May 2017, 0600 to 1900UTC
From 21 Sep 2017, 0800 to 1700UTC
From 13 Apr 2018, 0600 to 1900UTC
From 17 Nov 2018, 0700 to 1800UTC
From 20 Mar 2019, 0600 to 2100UTC
From 30 Oct 2019, 0700 to 1800UTC
From 17 Apr 2021, 0600 to 2100UTC
From 28 Oct 2021, 0700 to 1800UTC
From 18 Apr 2022, 0600 to 2100UTC
From 14 Oct 2023, 0700 to 1800UTC
From 06 Mar 2024, 0800 to 1800UTC
The beacon is at a site that is solar and wind powered only, and also supports 2m and 70cm repeaters. In order to keep within the energy budget, the times of operation are limited and may be subject to some outages especially during winter.
The keyer sends a code for the battery voltage.
Sound recording
GB3USK 19/04/2017


Thanks for all the reports!!
Standard reception reports are appreciated, please use
At that site you can see the latest coverage map - one below is for 15/09/2019

In case of interference or other faults please report them by email to g3tct (at)
Spots at 19/11/2018

Recent rain scatter event

21 July 2017 event showing rain returns up to 180Hz LF of the signal on both mark and space, whilst beaming ~30degrees north of direct path.
21 July 2017 rain scatter


GB3USK is the callsign of the 23cm beacon originally installed near Bristol but named after the town of Usk in south Wales.  Its parameters were:-
Frequency 1296.875MHz, Mode  F1, Locator IO81QJ, Antenna 15 over 15ele beaming east, beacon keeper: GW8AWM

Due to the withdrawal of site permission, the beacon had to close down in June 2013.


Thanks are due to the following