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THE TRANSMISSION GALLERY
WESTERGLEN
| Photos by Jack Richardson | Page last updated: 2024-10-20 |
| A day trip down to the central belt saw me and a friend make a stop at Westerglen. There is a footpath which runs to the side of the site, allowing some of these photos, as well as vantage points from the road. There are good views towards the Ochil Hills, the Southern Highlands and the Firth of Forth. I have seen Westerglen from higher parts of Glasgow, Arthur's Seat and the M9. Unfortunately, my camera sensor was a bit dirty at the time, so please excuse some of the marks on these photos. |
| The overall setup at Westerglen. From left - a mobile phone tower, the reserve 64m high MW mast, the MW mast, and the LW mast. The Ochil Hills are in the background. |
| The LW mast on the left, the MW mast on the right. |
| Starting off with the Long Wave mast. |
| At the very top of the Long Wave mast are nine wires, each 180m long which form an umbrella configuration. This effectively increases the electrical length and so raising the radiation resistance, which draws more RF current into the radiator so it radiates more efficiently. The lower section of these nine wires are held in position with parafil rope. |
| Moving over to the MW mast... |
| Ofcom data indicates that 810 kHz and 909 kHz are transmitted omni directionally. Therefore it is assumed that both of these services are transmitted by the mast, as a straightforward mast radiator. 1089 kHz (and 1215 kHz, before Absolute Radio closed), both had 'figure-of-eight' horizontal radiation patterns, with the maxima directed towards the main population centres of Glasgow and Edinburgh, with the minima in the direction of the principle co-channel transmitter at Moorside Edge. I believe that the additional wires suspended on either side of the mast form a "Spaced Vertical Wire Aerial" for both these services. The two wires being driven in anti-phase to achieve the 'figure=of-eight' horizontal radiation pattern. The mast has no influence on the radiation pattern, because the currents induced in it by the two wires are in anti phase and therefore cancel one another. A similar arrangement exists at Moorside Edge. |
| The same picture with the 'Spaced Vertical Wire Aerial' highlighted in red. The insulated support wires are coloured yellow. |
| Diagrammatically. |
| Reserve mast and dish |
| Mobile phone tower |
| Various signs |
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