UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Television and Video

Notices

Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc.

Reply
 
Thread Tools
Old 16th Aug 2013, 9:31 pm   #21
HamishBoxer
Dekatron
 
HamishBoxer's Avatar
 
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 5,308
Default Re: 405-Line VHF Aerials in 2013

Despite the hard climate, many large Band 1 arrays are still surviving up here in the frozen North. Must post my pictures from Grantown-On Spey.
__________________
G8JET
HamishBoxer is offline   Reply With Quote
Old 18th Aug 2013, 1:03 am   #22
crusher19860138
Hexode
 
Join Date: Sep 2010
Location: Stourbridge, West Midlands, UK.
Posts: 408
Default Re: 405-Line VHF Aerials in 2013

Quote:
Originally Posted by Nicklyons2 View Post
And here's another great survival - even the UHF on this installation is pretty ancient.
I bet the UHF is still giving good service as well!
crusher19860138 is offline   Reply With Quote
Old 18th Aug 2013, 1:05 am   #23
crusher19860138
Hexode
 
Join Date: Sep 2010
Location: Stourbridge, West Midlands, UK.
Posts: 408
Default Re: 405-Line VHF Aerials in 2013

Saw a double six Band 3 aerial on a high south facing wall ,atop a 20 ft pole in Ludlow recently, I guess it must be pointing towards Wenvoe?
crusher19860138 is offline   Reply With Quote
Old 18th Aug 2013, 12:26 pm   #24
Tazman1966
Octode
 
Tazman1966's Avatar
 
Join Date: May 2006
Location: St Albans, Herts, UK.
Posts: 1,970
Default Re: 405-Line VHF Aerials in 2013

More than likely St Hilary on channel 10.
__________________
All the very best,
Tas
Tazman1966 is offline   Reply With Quote
Old 18th Aug 2013, 7:39 pm   #25
SwanseaSteve
Tetrode
 
Join Date: Aug 2013
Location: Swansea
Posts: 62
Default Re: 405-Line VHF Aerials in 2013

Could have been either St. Hilary or Wenvoe. From 1963 Wenvoe radiated 200kW EIRP on Ch13, and from 1965 St. Hilary was radiating Ch10 towards the South West of England and Ch7 northwards towards Wales (and the Ludlow site mentioned here).

But from Ludlow, surely Ridge Hill on Ch6 was a better bet?
SwanseaSteve is offline   Reply With Quote
Old 21st Aug 2013, 9:50 am   #26
Focus Diode
Octode
 
Focus Diode's Avatar
 
Join Date: Jan 2006
Location: Borough of Gateshead, UK.
Posts: 1,187
Default Re: 405-Line VHF Aerials in 2013

Quote:
Originally Posted by SwanseaSteve View Post
But from Ludlow, surely Ridge Hill on Ch6 was a better bet?
I thought that too, but Ridge Hill ch6V didn't open until 30/07/68!

Brian

Last edited by Focus Diode; 21st Aug 2013 at 10:03 am.
Focus Diode is offline   Reply With Quote
Old 21st Aug 2013, 9:58 am   #27
SteveCG
Octode
 
Join Date: Jun 2009
Location: Herefordshire, UK.
Posts: 1,746
Default Re: 405-Line VHF Aerials in 2013

A couple of thoughts on the Ludlow aerial:

1) Ghosting may have been a problem from Ridge Hill (RH) - hence a double;

2) The aerial could have been orginally pointed to Litchfield, and just turned when
RH opened. Many aerials in Hereford city, originally for Litchfield, were just turned when RH started; and a CH 8 aerial will work acceptably on CH 6.
SteveCG is offline   Reply With Quote
Old 22nd Aug 2013, 10:58 pm   #28
SwanseaSteve
Tetrode
 
Join Date: Aug 2013
Location: Swansea
Posts: 62
Default Re: 405-Line VHF Aerials in 2013

Even here in Swansea, a South Wales coastal town famous for its wild weather off the sea, I do know of a couple of Band I aerial installations still standing. No sign of any coax leading to them though - I imagine that the constant flapping in the breeze has done for the cables by way of metal fatigue long ago.

Worth keeping in mind that there might be a number of Band III aerials on roofs there days for the purpose of receiving DAB radio. In many cases, these might even be pointing at the same masts as Band III television aerials once did! I suppose the differences that give the game away would be that the DAB aerials are shinier, and do have coax cables attached.

Apart from that, they're going to look identical (though they're actually very slightly smaller that an old 405-line channel B13 aerial). DAB is transmitted on channels whose numbers are based on the European 7-MHz system B channel numbering, and here in the UK we seem to be mostly using channels E11 and E12 (216 - 230MHz) for the job.
SwanseaSteve is offline   Reply With Quote
Old 23rd Aug 2013, 7:25 am   #29
Nicklyons2
Octode
 
Nicklyons2's Avatar
 
Join Date: Jan 2013
Location: Barnsley, South Yorkshire, UK.
Posts: 1,515
Default Re: 405-Line VHF Aerials in 2013

It's not only the shining metal which gives away the new Band III aerials it is also the gauge of the metal, the often strange folded dipoles with huge connecting boxes and the eccentric spacing of the elements, (I would suspect), to get a measure of broadbandiness whilst staying compact.
Nicklyons2 is offline   Reply With Quote
Old 23rd Aug 2013, 2:35 pm   #30
ntscuser
Pentode
 
ntscuser's Avatar
 
Join Date: Mar 2013
Location: Coventry, West Midlands, UK.
Posts: 241
Default Re: 405-Line VHF Aerials in 2013

The multi-element DAB aerial for a nearby flats complex is pointed towards the old Lichfield ITV transmitter and is definitely powerful enough to pick up a TV signal from there if there was still one. The elements are much closer spaced than usual and raked forwards but as far as I can tell (from ground level) it is not a log-periodic design. I've so far been unable to determine its make or find a picture of one.
__________________
Classic TV Show Theme Tunes
ntscuser is offline   Reply With Quote
Old 1st Sep 2013, 7:59 am   #31
crusher19860138
Hexode
 
Join Date: Sep 2010
Location: Stourbridge, West Midlands, UK.
Posts: 408
Default Re: 405-Line VHF Aerials in 2013

I remember walking past a cottage at Rodley,Gloucestershire around 1981,and seeing a double six in the front garden on a 15ft pole,pointing roughly NW,as all other aerials were by this time UHF and pointed the opposite way towards Mendip,i stopped outside this cottage for a break as it was a hot summers day,the cottage window was open and i remember hearing the ATV ident tune,happy days!
crusher19860138 is offline   Reply With Quote
Old 21st Sep 2013, 9:20 pm   #32
Focus Diode
Octode
 
Focus Diode's Avatar
 
Join Date: Jan 2006
Location: Borough of Gateshead, UK.
Posts: 1,187
Default Re: 405-Line VHF Aerials in 2013

A couple of great examples spotted in the Kings Cross area of London over the past couple of days.

Note the folded CH1 X-dipole in the first photo. The second was spotted this very morning on having breakfast inside a hotel in the area. The CH9 array looks to be an Antiference "Trumatch" design. There was another ch1 & 9 set up which had collapsed a house or two away. Nearby UHF aerials have been painted out for clarity.

Cheers,
Brian
Attached Thumbnails
Click image for larger version

Name:	Incl Paris and London 083.jpg
Views:	344
Size:	36.8 KB
ID:	84284   Click image for larger version

Name:	Incl Paris and London 084.jpg
Views:	325
Size:	51.8 KB
ID:	84285  
Focus Diode is offline   Reply With Quote
Old 22nd Sep 2013, 11:13 am   #33
malvision
Tetrode
 
Join Date: Feb 2009
Location: Wirral, Merseyside, UK.
Posts: 93
Default Re: 405-Line VHF Aerials in 2013

The easiest way to Aerial spot, is using google maps street view. Quite interesting how many 405 aerials you see, if you pick the right areas.
malvision is offline   Reply With Quote
Old 22nd Sep 2013, 1:29 pm   #34
colly0410
Pentode
 
Join Date: Jul 2009
Location: Hucknall, Nottinghamshire, UK.
Posts: 195
Default Re: 405-Line VHF Aerials in 2013

Would a folded X work any better than a normal X or was it a gimmick?
colly0410 is offline   Reply With Quote
Old 23rd Sep 2013, 9:23 am   #35
SteveCG
Octode
 
Join Date: Jun 2009
Location: Herefordshire, UK.
Posts: 1,746
Default Re: 405-Line VHF Aerials in 2013

Re post no. 24

An interesting question! There was a maker/brand? 'Dublex' in the late 40s - 50s who made such an aerial. A moderate pig to take apart - unlike the Antiference Antex X. If I remember correctly the elements were internally connected in a different way to the Antex. With twice the amount of metal they must have been more expensive than the Antex, but I bet the performance was similar - possibly a difference in the impedance??

Perhaps somebody with a good back collection of Wireless World adverts of that era could establish who came first in the X design league?
SteveCG is offline   Reply With Quote
Old 23rd Sep 2013, 9:47 am   #36
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 5,058
Default Re: 405-Line VHF Aerials in 2013

Quote:
Originally Posted by colly0410 View Post
Would a folded X work any better than a normal X or was it a gimmick?
I guess it depends on how they were connected up: if the ends of each 'leg' were simply paralleled at the feedpoint it would work as a fat element and this generally gives increased bandwidth compared with a single thin element.

This would only really be relevant though if you were trying to cover several Band-I channels where the frequency range is large compared with the resonant bandwidth of a half-wave element.

Some of the currently available DAB and Band-II dipole antennas _appear_ to be a folded dipole but the ends of each leg are paralleled at the feedpoint to give a 'fat' element.
G6Tanuki is online now   Reply With Quote
Old 23rd Sep 2013, 12:01 pm   #37
colly0410
Pentode
 
Join Date: Jul 2009
Location: Hucknall, Nottinghamshire, UK.
Posts: 195
Default Re: 405-Line VHF Aerials in 2013

When I lived in Bestwood Village near Nottingham we had a strange looking aerial, it was like a bent H with the dipole & reflector at about 45 degrees, sort of like two V's sideways on, we didn't have a seperate band 3 aerial. How did it work? My theory, (probably wrong) on band 1 a slightly degraded bent dipole + reflector. On band 3 as it's about 1.5 wave-lengths long it acts as the front (or is it the back) of a rhombic aerial.... BTW it was a good FM aerial till the wind blew it down in the late 70's. (I was in the Army in Germany so couldn't salvage it.)
colly0410 is offline   Reply With Quote
Old 23rd Sep 2013, 2:05 pm   #38
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 5,058
Default Re: 405-Line VHF Aerials in 2013

There was at least one design of combined B1/B3 antenna like you describe, though not all of them had the "delta-wing" swept-back style (this was probably more based on marketing than RF theory!)

The usual approach was that the boom part was actually a transmission-line and both the elements of the "H" were connected to the antenna feedpoint, one set directly the other via the transmission-line, in the style of the "ZL Special" or "HB9CV" 2-element beams used by us amateur-radio types.

On B3 it would work like the HB9CV/ZL and provide a bit of gain/directivity; on B1 one pair of elements would have been largely irrelevant, the other pair would be a 'short' dipole brought up to resonance by the transmission-line boom, and probably be a few dB down on an undistorted dipole.

Alternatively could it have been something like this:

http://www.wrightsaerials.co.uk/aeri...ient/019.shtml

--G6Tanuki
G6Tanuki is online now   Reply With Quote
Old 23rd Sep 2013, 3:48 pm   #39
ntscuser
Pentode
 
ntscuser's Avatar
 
Join Date: Mar 2013
Location: Coventry, West Midlands, UK.
Posts: 241
Default Re: 405-Line VHF Aerials in 2013

Quote:
Originally Posted by G6Tanuki View Post
Alternatively could it have been something like this:

http://www.wrightsaerials.co.uk/aeri...ient/019.shtml
That looks very much like the modern-day DAB aerial mounted on a nearby flats complex!
__________________
Classic TV Show Theme Tunes
ntscuser is offline   Reply With Quote
Old 23rd Sep 2013, 8:10 pm   #40
colly0410
Pentode
 
Join Date: Jul 2009
Location: Hucknall, Nottinghamshire, UK.
Posts: 195
Default Re: 405-Line VHF Aerials in 2013

Re post # 38... I never thought about both elements being driven, I just assumed it was some kind of bent H. It seemed to work OK, my mate a few doors away had an X for BBC + a 5 element yagi for ITV & our reception was just as good as his. I never saw it close up as when it blew down it must have been binned, when I came back from Germany it was gone..
colly0410 is offline   Reply With Quote
Reply

Thread Tools



All times are GMT. The time now is 1:25 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright ©2002 - 2017, Paul Stenning.