Film-Tech Forum ARCHIVE: Large (I'm not joking) tuning coil)

This is topic Large (I'm not joking) tuning coil) in forum Film-Yak at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=8;t=005230

Posted by Stephen Furley (Member # 1277) on 09-21-2007, 03:37 PM:

This might interest some of the radio people here.

Until earlier this year a time signal was transmitted from Rugby, in central England. For some years this had been the only signal transmitted from Rugby. This transmitter has now been shut down, and the signal is now transmitted from Cumbria, in the North-West.

There are some pictures on the 'Sub-Brit' website; they are an organisation which visits mainly underground installations in the UK, including many cold war bunkers, etc. However, they do visit some above ground installations as well. Scroll down this page for a picture of the tuning coil for this very low frequency signal: web page

There are pictures of a similar coil being delivered to the science museum store here

Posted by Jeff Stricker (Member # 224) on 09-22-2007, 05:57 AM:

Great website, Stephen. Yes, super large coils, and antennas too, required for operation on such low frequencies. Seems a shame all this vintage technology is going away a piece at a time. Some amateurs are now experimentng on 500 kHz (now that it is no longer used for marine service), but that's EHF compared to the 16 kHz transmitter on your website! Jeff W9GY

Posted by Stephen Furley (Member # 1277) on 09-22-2007, 01:35 PM:

If the windings are five metres across, then that thing must stand something like twelve metres high!

If you look at the last picture on the Science Museum site, you can see that there's somebody standing in a doorway behind the coil, and they are not standing very far behind the coil; this gives some indication of the scale. The picture before this one shows that the windings of the coil seem to be made of large-diameter copper tube, about the size of locomotive boiler tubes; I doubt that many of things will get preserved; they must be worth a fortune in the scrap value of the copper alone.