UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV 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 2nd May 2016, 8:49 pm   #381
Nymrod121
Nonode
 
Nymrod121's Avatar
 
Join Date: Apr 2012
Location: Worcestershire, UK.
Posts: 2,055
Default Re: 405-Line VHF Aerials 2013 to the present day.

Here are three venerable aerials seen earlier today in Bourton on the Water, Gloucestershire.
The vertically-polarised Band III Yagi stack is only missing half of one director ... not bad for a system that must be at least fifty years old.
Best wishes
Guy
Attached Thumbnails
Click image for larger version

Name:	20160502_103149-1.jpg
Views:	378
Size:	35.7 KB
ID:	123893   Click image for larger version

Name:	20160502_103156-1.jpg
Views:	334
Size:	55.8 KB
ID:	123894   Click image for larger version

Name:	20160502_104139-1.jpg
Views:	356
Size:	22.8 KB
ID:	123895  
__________________
"What a depressingly stupid machine." [Marvin: HHGTTG]
Nymrod121 is offline   Reply With Quote
Old 3rd May 2016, 3:41 pm   #382
SteveCG
Nonode
 
Join Date: Jun 2009
Location: Herefordshire, UK.
Posts: 2,497
Default Re: 405-Line VHF Aerials 2013 to the present day.

The Band III double 6 aerial is a Belling & Lee - indeed a well made aerial that still passes the test of time. I'm not sure of the Band I 'H' - other than it is a 1/4 wave design and they were not the cheapest to buy.

In the background of the 4 element Band I aerial photo there looks to be part of a J-Beam skeleton slot Band III. Early J-Beam - another well made aerial - all nuts and bolts Al alloy so little corrosion; the only weakness was in the waterproofing of the junction box.
SteveCG is offline   Reply With Quote
Old 3rd May 2016, 5:16 pm   #383
Herald1360
Dekatron
 
Herald1360's Avatar
 
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,546
Default Re: 405-Line VHF Aerials 2013 to the present day.

Aren't those band 3 aerials bayed, not stacked?
__________________
....__________
....|____||__|__\_____
.=.| _---\__|__|_---_|.
.........O..Chris....O
Herald1360 is offline   Reply With Quote
Old 4th May 2016, 1:07 pm   #384
SteveCG
Nonode
 
Join Date: Jun 2009
Location: Herefordshire, UK.
Posts: 2,497
Default Re: 405-Line VHF Aerials 2013 to the present day.

If by 'bayed' you mean side-by-side; and 'stacked' one above the other, then I would agree Herald1360.

In practice, doubles seemed to have been more intended to reduce side-lobes than necessarily increase forward gain.

P.S. looking at the 4 element Band I aerial in post no. 381 I suggest it was/is a channel B5, therefore looking to the BBC Wenvoe transmitter site.

Last edited by SteveCG; 4th May 2016 at 1:10 pm. Reason: Added suggestion
SteveCG is offline   Reply With Quote
Old 13th May 2016, 9:34 am   #385
Focus Diode
Octode
 
Focus Diode's Avatar
 
Join Date: Jan 2006
Location: Borough of Gateshead, UK.
Posts: 1,420
Default Re: 405-Line VHF Aerials 2013 to the present day.

Revisiting Kings Cross earlier in the week, see post #32. Someone has since attached a satellite dish to the VHF mast. The other set with the folded BI elements is also still standing but on the verge of collapse.

I've seen many instances of UHF aerials attached to existing VHF poles but never a satellite dish until now!

Brian
Attached Thumbnails
Click image for larger version

Name:	Kings Cross aerials 10-05-16.JPG
Views:	349
Size:	68.6 KB
ID:	124424  
Focus Diode is offline   Reply With Quote
Old 13th May 2016, 9:41 am   #386
Nymrod121
Nonode
 
Nymrod121's Avatar
 
Join Date: Apr 2012
Location: Worcestershire, UK.
Posts: 2,055
Default Re: 405-Line VHF Aerials 2013 to the present day.

Quote:
Originally Posted by Herald1360 View Post
Aren't those band 3 aerials bayed, not stacked?
Oops ... yes, you're right, Chris!
__________________
"What a depressingly stupid machine." [Marvin: HHGTTG]
Nymrod121 is offline   Reply With Quote
Old 13th May 2016, 11:17 am   #387
SteveCG
Nonode
 
Join Date: Jun 2009
Location: Herefordshire, UK.
Posts: 2,497
Default Re: 405-Line VHF Aerials 2013 to the present day.

Re; post nos 32 and 385,

I've been puzzling over that Band III yagi. although it looks like an Antiference Trumatch product, I'm not so sure. There were other aerial makers who copied the Trumatch concept. The difference on the skyline comes down to close examinations of the element holders and the junction box. Antiference used a special round mounting (called rota-click ?) for the non-junction box elements and also special junction box fittings. The aerial in the picture does not, to me at anyrate, have the 'right' fittings for it to be an Antiference product. Perhaps Telerection?
SteveCG is offline   Reply With Quote
Old 26th May 2016, 4:38 pm   #388
Panrock
Nonode
 
Panrock's Avatar
 
Join Date: Feb 2005
Location: Worcestershire, UK.
Posts: 2,541
Default Re: 405-Line VHF Aerials 2013 to the present day.

Spotted today atop a shop in Evesham High Street... a 3-element Channel 4 array for Sutton Coldfield, missing the top half of its dipole.

Steve
Attached Thumbnails
Click image for larger version

Name:	20160526_152101.jpg
Views:	309
Size:	53.3 KB
ID:	125027  
__________________
https://www.radiocraft.co.uk
Panrock is offline   Reply With Quote
Old 29th May 2016, 4:06 pm   #389
Focus Diode
Octode
 
Focus Diode's Avatar
 
Join Date: Jan 2006
Location: Borough of Gateshead, UK.
Posts: 1,420
Default Re: 405-Line VHF Aerials 2013 to the present day.

Spotted this nice arrangement in Hexham earlier today, note the folded BI dipole.
The UHF aerial to the left is on the verge of collapse!

Brian
Attached Thumbnails
Click image for larger version

Name:	Edited_ImageEasyImageEditor_20160529_84.jpg
Views:	321
Size:	39.6 KB
ID:	125181  
Focus Diode is offline   Reply With Quote
Old 29th May 2016, 6:05 pm   #390
ntscuser
Hexode
 
ntscuser's Avatar
 
Join Date: Mar 2013
Location: Coventry, West Midlands, UK.
Posts: 280
Default Re: 405-Line VHF Aerials 2013 to the present day.

Quote:
Originally Posted by Focus Diode View Post
Spotted this nice arrangement in Hexham earlier today, note the folded BI dipole.
The Band I element spacing is correct for 75 Ohms but wouldn't the Band III aerial be closer to 300 Ohms?
__________________
Classic TV Show Theme Tunes
ntscuser is offline   Reply With Quote
Old 31st May 2016, 10:43 am   #391
SteveCG
Nonode
 
Join Date: Jun 2009
Location: Herefordshire, UK.
Posts: 2,497
Default Re: 405-Line VHF Aerials 2013 to the present day.

Re posts no. 389 & 390

That Band I design seemed to perform well into 75 Ohm. As for the Band III design, well I've come across such aerials and they work - but I suspect the aerial impedance is more likely to be in the low one hundred than that of a 300 Ohm single folded dipole. Aerial design was/still is a bit of a black art (even with computer modelling).
SteveCG is offline   Reply With Quote
Old 17th Jul 2016, 12:59 pm   #392
sexton_mallard
Heptode
 
sexton_mallard's Avatar
 
Join Date: Sep 2013
Location: Ellesmere, Shropshire, UK & Co. Cork, Ireland.
Posts: 521
Default Re: 405-Line VHF Aerials 2013 to the present day.

Here is a tidy 405 line VHF specimen seen today in Ellesmere, Shropshire still pointing to (I think) Winter Hill along with most of its newer UHF companions.
Attached Thumbnails
Click image for larger version

Name:	SAM_3313.jpg
Views:	337
Size:	50.6 KB
ID:	127505  
__________________
Dom

Less snakes...more ladders!

Last edited by sexton_mallard; 17th Jul 2016 at 12:59 pm. Reason: Correct typo.
sexton_mallard is offline   Reply With Quote
Old 17th Jul 2016, 1:07 pm   #393
Nuvistor
Dekatron
 
Nuvistor's Avatar
 
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,450
Default Re: 405-Line VHF Aerials 2013 to the present day.

We're the UHF aerials pointing to Winter Hill or possibly The Wrekin transmitters? Well apart from the one being used for moon bounce.
If so that band 3 aerial could be ch 8 Lichfield.
Frank
Nuvistor is offline   Reply With Quote
Old 17th Jul 2016, 1:16 pm   #394
sexton_mallard
Heptode
 
sexton_mallard's Avatar
 
Join Date: Sep 2013
Location: Ellesmere, Shropshire, UK & Co. Cork, Ireland.
Posts: 521
Default Re: 405-Line VHF Aerials 2013 to the present day.

The site photographed is on the 'wrong' side of a hill for the Wrekin whereas most of the town points to the Wrekin and possibly Sutton Coldfield as well as Winter Hill as far as I know.
__________________
Dom

Less snakes...more ladders!
sexton_mallard is offline   Reply With Quote
Old 17th Jul 2016, 2:13 pm   #395
Nuvistor
Dekatron
 
Nuvistor's Avatar
 
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,450
Default Re: 405-Line VHF Aerials 2013 to the present day.

Hi Dom,
it was just a thought.
Frank
Nuvistor is offline   Reply With Quote
Old 17th Jul 2016, 11:06 pm   #396
Nicklyons2
Octode
 
Nicklyons2's Avatar
 
Join Date: Jan 2013
Location: Barnsley, South Yorkshire, UK.
Posts: 1,517
Default Re: 405-Line VHF Aerials 2013 to the present day.

Quote:
Originally Posted by sexton_mallard View Post
Here is a tidy 405 line VHF specimen seen today in Ellesmere, Shropshire still pointing to (I think) Winter Hill along with most of its newer UHF companions.
Could well be a Belling-Lee specimen; it exhibits their tendency to not use a driven dipole for Band III and instead just use the proximity of the shorter Band III rods to 'loose couple' to the Band I dipole. This, in effect, made it a 'ready-made' version of the clip-on Band III wings which were affixed to existing Band I aerials on the arrival of ITV.
Nicklyons2 is offline   Reply With Quote
Old 18th Jul 2016, 10:03 am   #397
Heatercathodeshort
Dekatron
 
Heatercathodeshort's Avatar
 
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,151
Default Re: 405-Line VHF Aerials 2013 to the present day.

Quote:
Originally Posted by ntscuser View Post
Quote:
Originally Posted by Focus Diode View Post
Spotted this nice arrangement in Hexham earlier today, note the folded BI dipole.
The Band I element spacing is correct for 75 Ohms but wouldn't the Band III aerial be closer to 300 Ohms?
It is interesting to note that a number of early Band 3 receivers had provision for 300 ohm balanced feeder on Band 3 only. J.
Heatercathodeshort is offline   Reply With Quote
Old 18th Jul 2016, 11:16 am   #398
peter_scott
Dekatron
 
peter_scott's Avatar
 
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 3,276
Default Re: 405-Line VHF Aerials 2013 to the present day.

I came across this interesting Yagi in an article about Spencer West who designed a low cost television for home construction in Television & Short-Wave World. He received good pictures in Beccles, Suffolk, 97 miles away from the Alexandra Palace transmitter in May 1938.

Peter
Attached Thumbnails
Click image for larger version

Name:	West Aerial (Medium).jpg
Views:	233
Size:	44.8 KB
ID:	127563  
peter_scott is offline   Reply With Quote
Old 18th Jul 2016, 11:40 am   #399
SteveCG
Nonode
 
Join Date: Jun 2009
Location: Herefordshire, UK.
Posts: 2,497
Default Re: 405-Line VHF Aerials 2013 to the present day.

Peter, re post no. 398,

... What an intriguing design! ...

I wonder what its reception of "Chain Home" 30 Mc/s radar was like ?
SteveCG is offline   Reply With Quote
Old 18th Jul 2016, 3:39 pm   #400
peter_scott
Dekatron
 
peter_scott's Avatar
 
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 3,276
Default Re: 405-Line VHF Aerials 2013 to the present day.

Hi Steve,

There were certainly enough along the East Anglian coast hitting it from the side although the aerial would be pointing towards Weymouth where they were a bit thinner on the ground and rather far way but I guess there would be quite a bit of testing going on throughout 1939. I don't know the actual frequencies but there were apparently four in the range 20 to 55MHz.

The one at Great Baddow that still exists could potentially have caused interference.

Peter

Last edited by peter_scott; 18th Jul 2016 at 4:07 pm.
peter_scott is offline   Reply With Quote
Reply

Thread Tools



All times are GMT +1. The time now is 6:55 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 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.