Today myself and the XYL and the harmonics paid a quick visit to the Ballygirreen antenna system which is used by Shanwick Aeronautical controllers for HF trans-Atlantic air traffic. We had seen them from the M18 a couple of days ago and this afternoon, on our way back from West Clare to Shannon, we came off the M18 to have a quick look.
There were what looked to be some very nice wire antennas although exactly what they were I could not tell. Having a quick read about Ballygirreen on the internet I found that the controllers are using FIVE kilowatts of power to make contact with planes out across the Atlantic. The maximum legal power in Ireland for amateur radio is 400 watts. So that's quite a lot more than we are allowed to use, although amateurs in Ireland will soon be allowed run 1.5kw during certain contests, subject to application. But Ballygirreen it seems is only a receive station. The transmit antennas, according to this document, are located at Urlanmore.
I have long had an interest in the trans-Atlantic HF traffic. I was listening to pilots talking to controllers in Shannon (Shanwick), Gander, Santa Maria, New York and further afield long before I ever took up an interest in listening to the amateur bands. For hours at night I would listen on my IC-R75 receiver with a random l-shaped longwire listening antenna strung out the window and down to the bottom of the garden. It's amazing what you can hear on a random length of wire. I would often have heard the Auckland Volmet (automated weather readout) early in the morning, and indeed the Brisbane Volmet too.
If any of you are interested in monitoring the Shanwick communications, first try to see if you can pick up the Shannon Volmet on 5.505 kHz, upper side band. Needless to say those living in Shannon, near to the Urlanmore antennas, will have the Volmet 60 db over s9 even on a one-foot piece of wire.
Primary frequencies to monitor would be 5.598, 5.649 and 8.879.
My xyl did take photos of the Ballygirreen antennas out of the car but I am unable to hook the camera up to this laptop because I did not bring a cable but I will upload some tomorrow all going well.