The Alderney site used to play a major part in bringing TV and FM radio to the Channel Islands. It was originally developed by the British Post Office to relay VHF band III television transmissions for the ITA for Channel Television. Responsibility for the site subsequently passed to the States of Guernsey Telecommunications Board who then leased the site to the IBA.
In the mid 1970's Alderney was re-engineered for UHF reception from Stockland Hill. Fremont Point, the main transmitter on Jersey, commenced UHF transmissions on 26th July 1976. The IBA chose to use four panel aerials arranged as a steerable adaptive array, known by the acronym SABRE. The BBC used an array of 24 log periodics, together with the upper of the two parabolic reflectors operating in diversity. You can read more about these receiving arrangements and the original VHF band III installation, from the links at the foot of this page. The onward programme feeds to Fremont Point were via SHF links from the dish antenna at the top of the tower.
The UHF TV relay at Alderney entered service on 1st April 1977 and transmits from a conventional stack of 4 cardioid dipoles mounted at the top of the tower. A band II FM radio relay for Radio Guernsey was added in 2007.
From early 1984, the BBC was using Alderney as the receiving point for its network FM radio stations to provide stereo programme feeds to the Les Platons transmitter. This comprised 3 x 6-element band II Yagis on both North Hessary Tor & Rowridge, feeding diversity switched receivers. The onward link to Les Platons shared the TV, SHF link to Fremont Point using PCM. From July 1989 the BBC's NICAM distribution was extended to the Channel Islands via a digitally modulated UHF link, transmitted from Stockland Hill on UHF channel 30, with Alderney being the receiving point.
These days there ia a fibre-optic link to the islands. Much of the equipment we see installed on the Alderney tower is therefore now redundant, but certainly no less interesting for that. Would any tx-listers like to speculate on the functions of any of the other ironmongery?
The first five photos come from Peter Lonsdale and were taken soon after the UHF re-engineering work in the mid 1970's. They show both the BBC logs and the IBA Sabre panels, as well as the two 9 m dishes at some distance from the main tower. |
