|
General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
|
Thread Tools |
9th May 2021, 3:13 pm | #41 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,536
|
Re: Household aerial length limitation
Drone involvement?
Back to inspectors..... just a tape measure, a theodolite and a sliderule would suffice to calculate aerial lengths without leaving the ground
__________________
....__________ ....|____||__|__\_____ .=.| _---\__|__|_---_|. .........O..Chris....O |
9th May 2021, 4:46 pm | #42 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,918
|
Re: Household aerial length limitation
Was it ever enforced?
It looks like the sort of thing that might have seemed attractive to a legislator in the early days, thinking that a big aerial would suck all the signal out of the ether and spoil things for others. Or that people living near transmitters could steal electricity. Anyway, the surprising limitation in the licence has been publicised and no-one has come up with a definite basis. We've had a slight laugh at the silliness of it as well, so let's draw this one towards a close.... Does anyone know anything about the reason for the limitation? Last call!
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
9th May 2021, 6:21 pm | #43 | |
Dekatron
Join Date: Nov 2003
Location: Fakenham, Norfolk, UK.
Posts: 4,261
|
Re: Household aerial length limitaion
I've just been searching through my copy of Harmsworth - plenty there about aerials including full constructional and erection details for a 36ft. lattice mast at the far end from the chimney, but nothing as to the reason for the limit. I've always taken it to be aimed, as has already been said, at limiting the nuisance that could be caused by an oscillating TRF receiver.
Quote:
Paul |
|
9th May 2021, 6:32 pm | #44 | |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
|
Re: Household aerial length limitaion
Quote:
I would also say the same regarding radiation. I also read somewhere that the total length includes a wire that connects to an outside earth point although I can't see that on a copy of a licence I looked at. I had a look in W.W. for the reason for the rule but not found anything as yet. Lawrence. |
|
9th May 2021, 6:54 pm | #45 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,918
|
Re: Household aerial length limitation
Oscillating TRFs like super-regen sets is a good thought. It hadn't crossed my mind. I assume the limitation applied only to broadcast receivers and not to licensed amateurs because they would be using resonant aerials for transmission. Back in the day, the RSGB books covered Rhombics and Beveridges for the landed gentry.
Any earth wire inclusion in the allowance could be dodged by using a water pipe, I suppose. Aerials were a lot less well understood in those days. David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
9th May 2021, 6:59 pm | #46 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
|
Re: Household aerial length limitation
I was thinking of radiation to telephone/telegraph lines as one of the reasons.
Here's another 140ft reference, this is for the top wire in a T antenna with a center 30ft down lead: https://worldradiohistory.com/hd2/ID...%20erection%22 Lawrence. |
9th May 2021, 7:08 pm | #47 |
Dekatron
Join Date: Jan 2012
Location: Brentwood, Essex, UK.
Posts: 5,355
|
Re: Household aerial length limitation
The 1938 edition of Odhams "The Practical Handyman" has a chapter that includes how to install various types of outdoor and indoor radio aerials. It recommends a wire of about 40' for long wave and medium wave reception, this being the sum of the vertical and horizontal lengths, with the horizontal part about 25' above the ground. For short wave a horizontal dipole arangement using two lengths of wire each 15' long and connected via a twisted pair to a transformer at the set end was recommended.
it says: " Painted sectional masts, ready for assembly, are made in four sizes, namely 26, 30, 34 and 40 ft., and are supplied, complete with rings for anchoring the upper ends of the stay wires, a galvanised pulley, a halyard, a cleat and sufficient galvanised steel wire for staying purposes. A 26 ft. mast costs under £1." Interestingly, it recommends not using water or gas pipes for the earth due to the jointing compound ( it calls it "paint" ) used ar the pipe connectors, but instead a dedicated earth spike. Even more relevant today, with the widespread use of plastic pipes for gas and water mains. Last edited by emeritus; 9th May 2021 at 7:19 pm. Reason: Earthing arrangements added |
9th May 2021, 7:25 pm | #48 |
Dekatron
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 8,935
|
Re: Household aerial length limitation
Bottom line is, if there are no complaints then no one cares.
__________________
G8JET BVWS Archivist and Member V.M.A.R.S |
9th May 2021, 8:29 pm | #49 | |
Dekatron
Join Date: Nov 2003
Location: Fakenham, Norfolk, UK.
Posts: 4,261
|
Re: Household aerial length limitation
Quote:
"Under these regulations the combined height and length must not exceed 100 feet for receiving or transmitting aerials. This length is irrespective of the number of wires employed. By the length is meant the horizontal or main aerial span, and by the height the vertical height above the leading-in point. The regulations allow of the use of a four-wire or any other multi-wire aerial of, say, 75 feet in length, and a downlead of a number of wires 25 feet in length, so that the actual length of wire used in an aerial may considerably exceed 100 feet. The leading-in point is that point at which the wires enter the house... There are no regulations limiting the size of frame aerials and the like or the length of wire which may be used." |
|
10th May 2021, 8:38 am | #50 |
Octode
Join Date: May 2009
Location: Stevenage, Herts. UK.
Posts: 1,520
|
Re: Household aerial length limitation
So is the Bulgin aerial in post #30 six separate wires in parallel or a single wire snaking up and down? (I suspect the latter)
|
10th May 2021, 9:32 am | #51 | |
Heptode
Join Date: Jun 2017
Location: Southport, Merseyside, UK.
Posts: 646
|
Re: Household aerial length limitation
Quote:
There wiil be height restrictions in the vicinity of airports. I worked at a factory about a mile from Liverpool Airport. We had a water tower about 60 - 70 ft in height and had to have a red warning light fixed to the highest point.
__________________
Time flies like an arrow, fruit flies like a banana |
|
10th May 2021, 9:45 am | #52 | |
Dekatron
Join Date: Jul 2007
Location: Penrith, Cumbria, UK.
Posts: 3,687
|
Re: Household aerial length limitation
Quote:
So the ability to turn a domestic TRF receiver into an interference-providing transmitter would be mitigated partly by having a lesser aerial. Maybe not by much, though, depending on matching and all that.
__________________
Regds, Russell W. B. G4YLI. |
|
10th May 2021, 12:55 pm | #53 | |
Guest
Posts: n/a
|
Re: Household aerial length limitation
Quote:
|
|
10th May 2021, 10:58 pm | #54 |
Rest in Peace
Join Date: Jun 2006
Location: Chard, South Somerset, UK.
Posts: 7,457
|
Re: Household aerial length limitation
|
10th May 2021, 11:52 pm | #55 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,918
|
Re: Household aerial length limitation
Knowing the ingenuity native to these Brittanic Isles, Did anyone ever make a radio 200' long and attach the permitted 100' wire to it?
As soon as any law, rule or patent is issued, then the hunt is on to circumvent it. David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |