Channel 70 was a Dublin pirate radio station which was on air from 1970 – 1973 (despite the newspaper article reproduced below)
From The Evening Herald – January 22, 1972
A new pirate station began broadcasting in the Dublin area today. The station is called Channel 70 and is on 224 metres medium wave. Over the past few weeks there have been broadcasts from a pirate station in the early morning hours. The Post Office traced the station to the northside of the city.
Before signing off this morning the announcer told his listeners that he was not sure when Channel 70 would come on the air again, but promised to return with “some groovy sounds'”.