|Kylerhea village is on the coast of the Isle of Skye, Scotland. Although there is now a Skye Bridge a ferry still links Kylerhea to the mainland. Plotting the position of this transmitter on the map from the National Grid co-ordinates I thought I must have made a mistake. The site is well inland, half way along a high and remote pass with no inhabited buildings for miles. Nevertheless we trundled the Behemoth up seven miles of appalling road until, sure enough, there it was. And suddenly, everything made sense. The very top of the pass is the only place for miles around where TV signals can be received, for it is just possible to get a signal there from Skriaig which by lucky chance is straight along the glen. In the opposite direction the site commands a view of Kylerhea village, and also Glenelg on the mainland, both of which it serves.|
There was an odd thing about this relay - until recently its polarity had been listed wrongly in the reference sources! Every transmitter listing said that the polarity was vertical, but in fact it is horizontal.
Before the transmitter was built there had been a self-help station here. The pole pig on the nearby electricity pole is much older than the transmitter mast and buildings. At its foot there is a wooden box containing a domestic consumer unit, and on high ground near the present mast there is the stub of a mast, set in concrete (Image 1 below). This would have been the Rx aerial mast.
On lower ground, screened from the first mast, is a steel box held upright with binder twine (Image 2 below), and the remains of three guy rope anchors. This would be the transmission site. Now, the fact that the Tx and Rx sites are screened from each other strongly suggests that the station simply retransmitted the received signals on the same channels. Normal practice is to reverse the polarity when this is done, so the output would be horizontal (Skriaig being vertically polarised).
Obviously faced with two villages full of extant horizontal aerials, it obviously made sense for the new relay to be horizontally polarised but somehow this fact never made it to the listings. Happily, since the relay's appearance here on this web site the record is now being set straight!
The transmit aerials comprise six log-periodics, stacked one above the other. Six? All pointing in the same direction? How come? Had the station transmitted with vertical polarity it would probably have used the customary arrangement, with two sets of three log-periodics, each set pointing in the directions that needed the most signal. Dare I suggest that the engineers at this installation, faced with a "last minute" change of polarity but supplied with six log-periodics together with the phasing harnesses designed specifically to feed all six, decided to use the lot, but mount the arrays horizontally and point them all at Glenelg?