22nd Jul 2019, 1:38 pm | #661 |
Heptode
Join Date: Apr 2008
Location: Eastbourne, East Sussex, UK.
Posts: 671
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Re: 405-Line VHF Aerials 2013 to the present day.
Here's on local to me in Pevensey Bay, East Sussex, B1, 3 and 5 together, all seen better days! B3 VHF pointing to Dover, UHF to Heathfield.
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22nd Jul 2019, 2:18 pm | #662 |
Hexode
Join Date: Jan 2007
Location: Faro, Portugal
Posts: 269
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Re: 405-Line VHF Aerials 2013 to the present day.
The remains of the band 1 elements
look a bit short for Crystal Palace Ch1, probably for the Eastbourne relay on Ch 5. |
1st Aug 2019, 9:43 am | #663 |
Dekatron
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,147
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Re: 405-Line VHF Aerials 2013 to the present day.
Travelling back from Dulwich yesterday I spotted this interesting channel 1/9 aerial in Aberdeen Road Croydon.
It's surprising how many 405 aerials remain in this area literally within touching distance of CP and BH. I guess that being so close to the transmitter, the co-ax screening not being very efficient back then, would probably lead to ghosting and other odd effects. Being too close was probably as bad as being too far away! Regards, John. |
1st Aug 2019, 12:57 pm | #664 |
Heptode
Join Date: Apr 2008
Location: Eastbourne, East Sussex, UK.
Posts: 671
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Re: 405-Line VHF Aerials 2013 to the present day.
The high gain and narrow vertical beamwidth of the transmission antennas meant that areas in the immediate shadow of the mast often received poor pictures. See here for an explanation of the 'Penge Effect'
https://www.bbceng.info/Install/Tran...pub-effect.PDF |
1st Aug 2019, 1:03 pm | #665 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,433
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Re: 405-Line VHF Aerials 2013 to the present day.
Initial very local coverage of UHF from Winter Hill was a problem, it was resolved in the area I worked but not sure how Horwich, which is under the mast, faired.
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Frank |
1st Aug 2019, 1:42 pm | #666 |
Nonode
Join Date: Sep 2017
Location: Stockport, Cheshire, UK.
Posts: 2,004
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Re: 405-Line VHF Aerials 2013 to the present day.
I have some relatives in the Melton Mowbray area & their picture from Waltham was never brilliant, especially my Aunt & Uncle's in Great Dalby.
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Hello IT: Have you Tried Turning It Off & On Again? |
1st Aug 2019, 5:18 pm | #667 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 14,007
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Re: 405-Line VHF Aerials 2013 to the present day.
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1st Aug 2019, 5:25 pm | #668 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 14,007
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Re: 405-Line VHF Aerials 2013 to the present day.
Spotted today in Newbury, just off what everyone locally calls the "Halfords roundabout".
Pointing down the valley to London, the BI antenna has lost its dipole but the director remains. The side-by-side BIII antenna is a nice example of a "Slot-fed" double-Yagi with 'delta' matching back to the feedpoint. The coax from the BIII feedpoint has come away from the boom/mast and now trails sadly over the lower part of the 'slot' element. It's a rather well-constructed setup, with a big beefy clamp from the BI boom to the mast and paired paralleled arms supporting the two booms of the BIII array from the BI boom. I wonder if perhaps this design was originally BI-only and the BIII elements were retrofitted when ITV came available? |
2nd Aug 2019, 10:54 am | #669 |
Dekatron
Join Date: Jul 2008
Location: Charmouth, Dorset, UK.
Posts: 3,601
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Re: 405-Line VHF Aerials 2013 to the present day.
I had a customer that lived almost directly under the Stockland Hill mast and had a dreadful signal.
Peter |
2nd Aug 2019, 11:31 am | #670 |
Nonode
Join Date: Jun 2009
Location: Herefordshire, UK.
Posts: 2,495
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Re: 405-Line VHF Aerials 2013 to the present day.
Re post no. 668:
The Band III looks like a J-Beam design - except that I've never seen that mounting method used for J-Beam. No sure about the Band I maker, except that the substantial mounting clamp could also be a J-Beam design. |
12th Sep 2019, 9:31 pm | #671 |
Triode
Join Date: Jun 2013
Location: Werrington, Staffordshire, UK.
Posts: 34
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Re: 405-Line VHF Aerials 2013 to the present day.
Photographed in Lynton, Devon today.
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Cheers, Ian |
13th Sep 2019, 9:32 am | #672 |
Nonode
Join Date: Jan 2004
Location: 1966-1976 Coverack in Cornwall and Helston Cornwall. 1976-present Bristol/Bath area.
Posts: 2,967
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Re: 405-Line VHF Aerials 2013 to the present day.
Glad to see it is still there. I took a picture of this some years back. I think the problem in the Lynmouth/Lynton area was not to little but to much and to many signals. There is a clear 30 mile path across the Bristol Channel to both the high powered 405 line transmitters at Wenvoe on ch5 and St Hilary on ch10.
Because of these strong signals and the surrounding hills and cliffs multi path or ghosting was a severe problem on both channels. It was a nightmare for local aerial riggers who tried different types of aerials to try and overcome or reduce the ghost problem.
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Simon BVWS member |
13th Sep 2019, 9:19 pm | #673 |
Pentode
Join Date: Sep 2009
Location: Dundee, UK.
Posts: 158
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Re: 405-Line VHF Aerials 2013 to the present day.
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13th Sep 2019, 9:37 pm | #674 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 14,007
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Re: 405-Line VHF Aerials 2013 to the present day.
What a fascinating design.... I really can't figure it out properly! Is it just a BI design or is the 'skeleton slot' also supposed to provide some form of directionally-confused BIII coverage ??
It still seems to be a case of dipole-and-director [the director appears to have adjustably-extensible ends] which is a less-than-optimal design as far as gain and directivity/anti-ghosting is concerned. |
13th Sep 2019, 10:02 pm | #675 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,433
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Re: 405-Line VHF Aerials 2013 to the present day.
J-Beam HornBeam, see pages 418/419
https://americanradiohistory.com/Arc...ld-1956-09.pdf
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Frank |
13th Sep 2019, 10:17 pm | #676 |
Hexode
Join Date: Nov 2010
Location: Market Drayton, Shropshire, UK.
Posts: 485
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Re: 405-Line VHF Aerials 2013 to the present day.
Guest who fitted a few of them , called Hornbeam made by Jay beam
The band 1 rods are adjustable held in place by a set screw . The lasting kit had a bolt and sort of gear armament that was operated with a alan key . Did not fit many as this type of lashing kit was time consuming Derrick |
13th Sep 2019, 10:25 pm | #677 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
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Re: 405-Line VHF Aerials 2013 to the present day.
How well did they work?
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Frank |
26th Dec 2019, 8:40 pm | #678 |
Heptode
Join Date: Aug 2009
Location: Carshalton, Surrey, UK.
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Re: 405-Line VHF Aerials 2013 to the present day.
Hi,
spotted a while ago, but photographed today in Wallington Surrey. there is also another one on KIngston road in New Malden. I will take a photo when I can..
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Regards Peter B |
31st Jan 2020, 4:49 pm | #679 |
Nonode
Join Date: May 2006
Location: St Albans, Herts, UK.
Posts: 2,193
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Re: 405-Line VHF Aerials 2013 to the present day.
Here's one I didn't spot until today. It's round the corner from my house in the next street along here in St Albans. One of many ch1/ch9 combined arrays that were installed around here.
Sorry about the not too clever picture. I think the lens on my camera phone needs a clean
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All the very best, Tas |
1st Feb 2020, 11:17 am | #680 |
Dekatron
Join Date: Jul 2008
Location: Charmouth, Dorset, UK.
Posts: 3,601
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Re: 405-Line VHF Aerials 2013 to the present day.
Same antennas as we installed in Petts Wood in the '50s. We were looking directly at Crystal Palace but Croydon was off in the distance.
Peter |