Castlebar transmitter

The Castlebar transmitter is a relay station used to broadcast television and radio to a large part of County Mayo, Ireland, located at Croaghmoyle. The site is part of the RTÉ Network Limited transmission network.
The transmitter currently provides FM radio on VHF and a number of television stations on UHF.

Tawnycullawee deflector site

A separate, close-by site at Tawnycullawee was a television deflector station operated by Dropvale Limited, which carried channels from the UK as well as TV3 Eurosport and Sky News. The Tawnycullawee site is located at a lower altitude and transmitted on lower power than Croaghmoyle, as it is intended to serve the town of Castlebar and its immediate environs only. Today the site is used for Community Radio.

History

Opened in the early 1970's, the transmitter was originally a VHF television transmitter carrying RTÉ One and later RTÉ Two. These ceased transmission on VHF in 1999, after UHF transmissions from RTÉ1 and 2 began from the transmitter in 1998.
The first UHF transmissions were from TG4 in 1996 with RTÉ1 and 2 migrating to UHF in the years following.
FM radio transmissions began in 1992. In 2005 there was a major change to the frequencies used by the radio services in order to accommodate a new FM transmitter at Cairnhill.
UHF service began from Tawnycullawee in 1985. Originally this was an unlicensed transmitter but after a long campaign a licence was finally issued in 1999. This service ceased in 2012.
Following the issuing of the licence, UTV moved frequencies in 2000 and to occupy a channel previously used for Sky News.

Channels listed by frequency

Analogue Radio All services use vertical polorisation
* 89.3 MHz - RTÉ Radio 1 Croaghmoyle - 3kW EIRP
* 91.5 MHz - RTÉ 2fm Croaghmoyle - 3kW EIRP
* 93.7 MHz - RTÉ Raidió na Gaeltachta Croaghmoyle - 3kW EIRP
* 98.9 MHz - RTÉ lyric fm Croaghmoyle - 3kW EIRP
* 101.1 MHz - Today FM Croaghmoyle - 3kW EIRP
* 102.9 MHz - Community Radio Castlebar Tawnycullawee
* 103.7 MHz - iRadio NW - Croaghmoyle - 1kW EIRP
* 107.2 MHz - Newstalk - Croaghmoyle - 8kW EIRP

All services use Horizontal polorisation

* UHF 22 - Saorview 2RN Mux 2 - 1kW EIRP
* UHF 25 - Saorview 2RN Mux 1 - 1kW EIRP
Analogue Television -all services now ceased All UHF services used Horizontal polorisation
* UHF 23 - TG4 Croaghmoyle
* UHF 26 - TV3 '
* UHF 29 - RTÉ One Croaghmoyle previously VHF Ch D Vertical Originally Channel H.
* UHF 33 - RTÉ Two Croaghmoyle previously VHF Ch F Vertical
* UHF 39 - TV3 ' Tawnycullawee
* UHF 42 - ITV Tawnycullawee
* UHF 47 - BBC One Tawnycullawee
* UHF 50 -
* UHF 53 - BBC Two Tawnycullawee
* UHF 56 - Channel 4 Tawnycullawee