OVER 2 YOU 207 (23/11/04)

MYTHICAL ELECTRICITY?

I don’t know if this was an urban myth but many years ago I remember hearing or reading of a chap living near a large TV broadcast antenna who was able to save on electricity bills, lighting their home by tapping into the power coming from the transmitter.  I also live close to a TV mast and would be extremely interested to know if this is possible and if so, how it can be done.

Peter Stuart, via email

My brother in law's anti aircraft unit was guarding the Jerusalem radio transmitter in 1945 they illuminated their tents with a bulbs connected to a piece of wire. Peter Stuart should be warned that years ago the BBC successfully sued a Droitwich farmer for stealing power.

He was milking his cows courtesy their long wave transmitter!

Robin Mills, via email

It is very simple to light a building with power stolen from a nearby radio transmitter as a farmer once proved with a barn.

1. Ensure that the building is isolated and near a powerful transmitter,

2. Fit it with a metal roof (corrugated iron works well),

3. Connect the lights between the roof and a good earth connection,

4. Bask in the glow,

5. Explain why transmissions in your direction have suddenly reduced in power, probably in the local magistrates' court.

John R. Batts, Banbury

I recall a similar story about someone living in close proximity to the Crystal Palace TV mast who obtained power from the aerial using a dustbin lid mounted on his roof. Apparently the authorities finally nabbed him but the only offence they could charge him with was not being in possession of a current TV licence.

David Cummings, via email

Provided the transmitter is operating on LF or HF i.e. long, medium or short wave it is possible to draw power (a few watts) with a nearby resonant receiving aerial, I believe someone was caught doing this at my nearby Post Office Transmitting Station at North Weald in Essex, some years ago. However TV transmitters can be thought of as lighthouses beaming power towards the horizon. People living near a TV transmitter or cellular radio mast often get the worst signal as most of the power goes overhead. Special arrangements often have to be made (nullfill) to direct a small amount of signal downwards for these viewers. To obtain any reasonable power Mr Stewart’s receiving aerial would have to be at the same height as the white 'Dust Bin' at the top of the transmitting mast and nearly touching it. Just think of the 'Planning' and 'Health & Safety' issues, let alone cost, he would have to overcome just to light one bulb at ground level.

John Rollason, via email

Many years ago I remember hearing when the BBC began transmitting radio from Droitwich on 1500 metres (200khz) they had the most powerful transmitter anywhere. Local residents were using garden aerials at this time and were collecting enough power to light low powered light bulbs! The BBC threatened to sue these people for using up their power. It never came to court though, the residents promised to stop instead.  I can't vouch for any of the above, perhaps I dreamt it, but Peter's letter immediately brought it to mind.

Mike Cornick, via email

The story in Naval circles was that a chap living close to the low frequency aerials of the RN wireless station at Rugby assembled a huge induction coil in his roof to power his house, but was found out because communication with RN submarines were blacked over a quarter of the globe!

John Pengel

I don't know about taking electricity from TV transmitters but when I was working in Toronto in the early '50's a man with a house directly under some HT transmission lines fitted up some coils in his roof, which acted as the LT side of a transformer, the HT lines supplying the current. However Ontario Hydro noticed the extra "line leakage" traced it to the section of line over the house, found no obvious cause, noticed there were lights on in the house but no mains connection, found what the man had done, and he was convicted of stealing electricity. I suggest that Mr Stuart would do better to make himself some Dye Solar Cells (DSC see www.sta.com.au) fit them on his roof, and run a 12/24-volt lighting circuit. In volume production DSC are reportedly about 20% of the cost of equivalent Silicon PV Cells.

Andrew Stobart, Secretary, The Grünhaus Project, via email

I am afraid that Peter Stuart has been misled.  There is not the slightest chance of "tapping in" to the power being radiated even from the highest power stations.  Top start with, the radiation is shaped to send most of the power out in a horizontal direction to provide the best signal at a distance. Sufficient power is radiated to the area close in to deliver a useful signal and this is very little compared with the main beam.  The nearest that I have ever seen to this phenomenon is that with a long piece of wire (for the technical a half-wavelength) it used to be possible to light a small torch bulb connected in the middle when very close to the transmitting antenna of high power medium wave radio stations.  Sorry Peter but like the rest of us you will have to buy your power through your local supplier.

Ray Hills (one-time Assistant Director of Engineering IBA), via email

CUT THE CR*P

Advertisers and politicians can be difficult to judge as their words contain little or no meaning and are often self-contradictory. In the seventies there was a computer language called Structured English, which in the form used for program specifications was completely unambiguous. Is there a current computer program, which will read a statement or series of statements, validate them rejecting the invalid parts, and convert the rest into a language such as Structured English?

Brian Gilbert, Hampton Middlesex

I’m not sure about Structured English but there is a feature in Microsoft Word that automatically summarises a document, highlighting or abstracting key points and sentences. Go to Autosummarize on the Tools menu, select the summary style and length and click the OK button. I have found that it works well on verbose documents, particularly those produced by Government departments and official bodies where the author is clearly being paid by the word, or striving to make it as impenetrable as possible.

Hugh Stevens, via email

CAN YOU HELP?

I am an amateur horologist. Does anyone know of a PC program that will allow me to monitor and analyse the ticking of a mechanical clock, via a microphone, to assist with the adjustment of the pendulum or escapement?

Ben Stewart, via email

Whenever I sit down at the computer my cat insists on jumping on the table and plonking herself down in front of me, resting her backside on the keyboard, with predictable results. Has anyone any advice or suggestions for a humane deterrent, perhaps something that smells bad to cats (but not to humans, or damaging to computer keyboards) that will keep her away?

Violet Keys, via email