Band 1 TV Signals on the Cable TV systems in Ireland

Over the last few years, the Office of the Director of Telecommunications Regulation (ODTR) have eased the restrictions on operating on the 50 MHz band. Some of the main reasons for this easing of restrictions has been.....
1. The closure of the last Band 1 TV transmitter in Mahera, Co. Clare (53 MHz)
2. Careful operating over the last few years by EI stations.

One potential problem at the moment is that several Cable TV companies are using frequencies at and close to 50 MHz. It is important that anyone operating on the 50 MHz band at the moment does not cause any interference to the Cable TV signals.
The frequencies listed below are the carrier frequencies for the video signal. The video signals will cover a frequency range of the listed frequency plus about 5.5 MHz.
For example, suppose a channel listed below is listed as 48.000 MHz. The video signal for that channel will go from 48 MHz up to 53.5 MHz. So you can see that if you are operating on 50 MHz, your signal will be right in the middle of the video signal and potential problems could arise.
Remember that you might be running 10 to 100 watts on 6m. If this finds its way into the Cable TV system, it is competing with TV signals that are in the microwatt range. What's worse is that because the video part of the TV signal is in AM, you can still cause a lot of interference even if your signal is a lot weaker than the TV signals.

Wherever there are frequencies listed where your 50 MHz signal will be right in the middle of the video signal, I have marked it with !!!!!


Irish Multichannel

Limerick - 45.750 MHz - Skynews !!!!! , 53.750 MHz - Eurosport, 61.750 MHz - BBC2

Cork - 56.000 - Sky 1, 64.000 - Sky 2

Ennis - 45.750 - Eurosport !!!!! , 53.750 - TCC, 61.750 - Skynews

Athy - 45.750 - Eurosport !!!!! , 53.750 - UTV, 61.750 - CH4

Portarlington - 45.750 - Eurosport !!!!! , 53.750 - Sky 1, 61.750 - UTV

Ballinasloe - 45.750 MHz - Eurosport !!!!!, 53.750 MHz - Sky 1, 61.750 - UTV

Kilcullen - 45.750 - BBC 1 !!!!!, 53.750 MHz - Sky 1, 61.750 MHz - UTV


CMI

Athlone - 48.000 - TV5 !!!!! , 56.000 - BBC1, 64.000 - Sky News, 72.000 - CNBC

Carlow - 48.000 - C4 !!!!! , 56.000 - RTE1, 64.000 - Net2

Donegal Town - 45.750 - C4 !!!!! , 53.750 - Sky 1, 61.750 - BBC2

Greystowns - 48.000 - C4 !!!!! , 56.000 - BBC1, 64.000 - BBC2

Naas - 48.000 - Sky 1 !!!!! , 56.000 - C4, 64.000 - Sky News

Wicklow - 45.750 - Sky News !!!!! , 53.750 - HTV, 61.750 - C4

Portlaoise - 45.750 - C4 !!!!! , 53.750 - RTE1, 61.750 - NET2

Tullamore - 48.000 - RTE1 !!!!! , 54.000 - NET2, 64.000 - BBC2

Ballina - 45.750 - Sky 1 !!!!! , 53.750 - RTE1, 61.750 - NET2

Cellbridge - 48.000 - Sky News !!!!! , 56.000 - NET2, 64.000 - BBC2

Sligo - 48.000 - TNT !!!!! , 56.000 - RTE1, 64.000 - NET2

Swords - 48.000 - TV5 !!!!! , 56.000 - C4, 64.000 - Sky 1

Navan - 45.750 - Sky 1 !!!!! , 53.750 - NET2, 61.750 - RTE1

Newbridge - 48.000 - Sky News !!!!! , 56.000 - RTE1, 64.000 - NET2

Mullingar - 45.750 - NBC !!!!! , 53.750 - NET2, 61.750 - RTE1

Enniscorthy - 48.000 - C4 !!!!! , 56.000 - BBC1, 64.000 - BBC2

Maynooth - 45.750 - Skynews !!!!! , 53.750 - RTE1, 61.750 - NET2


NTL (Cablelink)

Dublin - 48.000 - NBC !!!!! , 56.000 - C4, 64.000 - Eurosport

Galway - 48.000 - NBC !!!!! , 56.000 - Sky 1, 64.000 - BBC1



If you have problems with interference, I would suggest the following :
1. Keep your 6m antenna as high and as far away as possible from the Cable TV system.
2. Use an antenna with a high front to back ratio and keep it pointed away from the Cable TV system. (Example = 2 EL Quad or 3 El Yagi). This can have the effect of reducing your signal in the direction of the Cable TV system by about 20 dB (ie. 100 times reduction in power. Its the same as reducing your power from 100 Watts down to 1 Watt)
3. Reduce your power. Run 5 Watts instead of 100 Watts. During the Summer Sporadic-E season, you will work lots of stations with 5 watts.

Credits : My thanks to Paul, EI6FE, for supplying me with the info on the cable TV frequencies.

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The URL of this page is http://www.qsl.net/ei7gl/band1tv.htm Last Modified : 2nd Sep 2000