This is a picture of the Loran lines at my location (about 200 km away from the cost). This may give you an indication about the problems and Loran windows that other stations living near a Loran stations might see (DF3LP send me a spectrogram depicting the awful receiving situation he has, his spectrogram looks like a zebra!).

The two yellow lines represent 137.695 kHz (lower line) and 137.705 kHz (upper line). A good window seems to be just above and below the double line at 137.686 kHz.

These Loran lines here are from the station on the island of Sylt in Northern Germany, how is the situation in other places (e.g. U.K.)? If you have a picture of Loran lines from your point of view, send it to me, I would like to put it here as an orientation guide.
 
 
 
In the Slow-CW window between 137.650 and 137.775 kHz tha I usually monitor, I can detect the following Loran-lines. You might want to avoiv those frequencies and better choose a frequency that is one or more Hertz away from one of those lines so that people living nearby the cost still can copy you: