Christopher - ha ha! yes, a horizontal coil with a sanded off strip and a slider! i have one of those... in fact, "that" is what came before the radio sink! back in 2009 i took a radio building workshop and wound magnet wire around a toilet paper tube, sanded the side, and used a paper clip as the tuner... the only electronic component was a single germanium diode. in the workshop, someone mentioned that they knew people in town who heard radio in their sinks and in their fridges from the shortwave site... so i decided to try to make my own radio sink. for the sink, i was trying to do it with no electronics and no wire at all... i was trying to use the copper pipe as the coil... that "tuning dial" pipe was playing the role of the paper clip... shorting out the coil at the desired frequency... but according to my calculations, i would have needed 40 metres of pipe! i had it in an art gallery once and cheated by putting an ipod in the drain pipe and attaching a speaker... but i felt dirty doing that... so, i may cheat a bit in a different way, and incorporate a real diode instead of trying to make one out of the drain trap. :-/
The Towers:
As for all those towers, it was the Radio Canada International shortwave transmission site. The 13 towers were merely the supports for the antenna curtains, horizontal wiring between them. Tower heights ranged from 150 feet to 430 feet tall. They were situated in that precise location and in that formation in order to take advantage of the conductive properties of the saltwater marsh (below sea level!) next to the Atlantic Ocean. They were situated to be able to broadcast across the ocean to Europe, Africa, South America, and the Arctic. Built during world war 2, and used heavily during the cold war. This site was also used by other countries, including Radio China, NHK Radio Japan, Voice of Vietnam, etc. etc. right up until 2012... when budget cuts came... the powers that be decided that everyone has access to internet or satelite now, so shortwave must be obsolete. HEARTBREAKING! (we all know that internet can be censored, and that digital recievers are not accessible to everyone) once torn down, this site will never be rebuilt now. I was there throughout the demolition... the antenna wire alone weighed 40 000 lbs of copper wire that went for scrap metal. The whole infrastructure was dismantled for scrap instead of reused. :-( I felt so helpless... a real loss for international communictions. i had no money to buy the site... no real power per se... so I was merely a witness... I documented all alone in the middle of winter... it was like watching something die. You can see a preview clip of my documentary here (I hope to have the film finished by August):
https://vimeo.com/63005991
and footage of the towers falling here (they did it in freezing cold winter so the marsh would be frozen enough that they wouldn't sink too deep when they fell):https://vimeo.com/89630404
Beth - getting AC power at 250 feet?... well, I work in film, and most film rental houses rent AC in 25 foot lengths, and we often rent quite a lot of it when working with lighting and such... 250 feet of AC easily gets used on a film set... so I figure I'll just rent a dozen or so 25 foot lengths of AC... carry it as a coil and unspool as I climb... or I was also thinking taking up a battery pack with a transformer to convert the DC to AC. Also, most towers have lights to warn airplanes... I doubt they have outlets to tap into... but you never know, each site is different... I still don't have permission to do this yet... so once I find a site that will give me permission, I would have to discuss electrical logistics and safety with the site manager. Likely I will have to get some hefty insurance too... last time I had to buy a sizeable liability insurance before they let me climb...
xtheremin8 - thanks for the info and the links! wicked!
and yes, placing contact mics on those wires... they were exactly like aeolian harps! the problem with the guide wires, vertical stays, and halyards, was that there was a lot of metal hardware and clamps that gave a more mechanical sound... i was surprised to find out that i got much better sound (drones with haunting harmonics and subharmonics) from the towers themselves. often from the ladder. a 430 foot ladder in high winds (winds on the marsh often get up to 50kph or more) makes for quite a vibration! I haven't cleaned up all the recordings yet, some still have a bit of noise, but each tower really did seem to have it's own voice... here is a link to the sounds of one of the towers (Tower O)... these are the sort of sounds I want to trigger with the theremins... and also the images... I would like to also trigger video so that when you are listening to tower O, you see the visual portrait of tower O:
Anyhow... if I do manage to get permission to take the Etherwave up a tower, in addition to AC, I'll probably have to figure out how to deal with temperature changes, as well as interference from the surrounding antenna... I won't be climbing or playing theremin near anything that is actively transmitting shortwave as the RF radiation is too dangerous for long exposure... so I think it will just be the metal, the wires, the temperature, and the heights that I will have to contend with. :-)