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-   -   405-Line VHF Aerials 2013 to the present day. (https://www.vintage-radio.net/forum/showthread.php?t=95890)

SteveCG 17th Aug 2017 2:52 pm

Re: 405-Line VHF Aerials 2013 to the present day.
 
Re post 495.

Alternatively the aerial could have "fallen off its perch" sometime - although the lashings look to still be the original. An aerial clamp issue then, I wonder ?

Hartley118 17th Aug 2017 4:34 pm

Re: 405-Line VHF Aerials 2013 to the present day.
 
As long as the downlead is still connected,, my guess is that it'll still be working. Gain probably a bit below spec though!

Martin

D Cassidy 17th Aug 2017 8:36 pm

Re: 405-Line VHF Aerials 2013 to the present day.
 
Quote:

Originally Posted by HamishBoxer (Post 968339)
With the weather up there I think explains it all. 10 long years I was up there and it was not good.

Hello HamishBoxer.
There are still plenty of old aerials dotted around my area.
Where were you located for those 10 long years?

Rhgbristol 9th Oct 2017 10:52 pm

Re: 405-Line VHF Aerials 2013 to the present day.
 
The photos in post 495 are the Ron Smith Galaxy band 11 FM radio aerial.

It is an aerial endorsed by Naim Audio for their overpriced FM tuners.

Not only does it pose serious structural concerns to most domestic chimneys, it also tells anyone in the know there's more than likely an audio system in the house worth in some cases tens of thousands of pounds!

I think I'd stick to an Antiference 5 element Mushkiller!

Heatercathodeshort 10th Oct 2017 6:42 am

Re: 405-Line VHF Aerials 2013 to the present day.
 
1 Attachment(s)
Yesterday I took a lorry to have it's tachograph calibrated to a garage at Horley, Surrey.

I had an hour to lose so took a walk along the A23, the old London Road to Brighton road.

These aerials are on the roof of an old mock Tudor Manor House probably dating from the 1920's.

It's amazing what you see when you take a walk. John.

Peter.N. 10th Oct 2017 12:54 pm

Re: 405-Line VHF Aerials 2013 to the present day.
 
Slant polarisation?;)

Peter

SteveCG 10th Oct 2017 1:19 pm

Re: 405-Line VHF Aerials 2013 to the present day.
 
By the looks of it not long before it goes to the 'great skip in the sky'.

Guest 10th Oct 2017 2:09 pm

Re: 405-Line VHF Aerials 2013 to the present day.
 
Quote:

It's amazing what you see when you take a walk.
And look up too, easy to miss something. That is why when visiting somewhere I walk round in both directions.

Heatercathodeshort 13th Oct 2017 2:27 pm

Re: 405-Line VHF Aerials 2013 to the present day.
 
5 Attachment(s)
I had some time to spare this morning and took these pictures in the Guildford area.

I had noticed most of them while driving tall vehicles but was never able to stop due to restricted space.

The first turned out to be most unusual as I only intended to take the picture of the simple dipole and ITA alone on the rooftop.

I parked up and walked back to discover the tops of an 'X' aerial behind the one I was about to catch.

Beside the house was a narrow access road that opened up into an area that consisted of what appeared to be small blocks of 'modern' maisonettes together with some much old Victorian properties.

I walked through and this is what I was confronted with.
On just one of the four two storey structures, still surviving on each corner are these rather large two band arrays.

I think this is possibly the only location where in 2017 three undamaged 405 line aerials can be seen in one picture taken facing the main road from the rear. John.

Heatercathodeshort 13th Oct 2017 2:33 pm

Re: 405-Line VHF Aerials 2013 to the present day.
 
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Driving back along the A281 just a short distance at the back of Tilehurst Road I managed to take a photo of a very unusual type.

I believe it was manufactured by 'K' Aerials of Guildford, the Band 3 section appearing to resemble a fish skeleton!

This was incredibly difficult to take this picture. I had to walk around a mile and climb an embankment getting very odd looks from motorists on the road beneath me. I hope it was worth it!

Heatercathodeshort 13th Oct 2017 2:37 pm

Re: 405-Line VHF Aerials 2013 to the present day.
 
2 Attachment(s)
In the centre of Godalming just outside Guildford on the A3100 another 'K' aerial was spotted some time ago. I captured it this morning as can be seen on these pictures.

How long the aerial will remain is anyone's guess and seeing all the modern buildings around it, even the chimney it is lashed to may be under threat... John

SteveCG 13th Oct 2017 3:31 pm

Re: 405-Line VHF Aerials 2013 to the present day.
 
Re posts 510 and 511. Great pictures of a real design rarity - worth the effort John ...
Belling & Lee did some similar ones but for Channel B4/B8 areas only.

Re post 509, 4th and 5th pictures - I reckon the Band III is a Belling & Lee design.

Heatercathodeshort 13th Oct 2017 5:20 pm

Re: 405-Line VHF Aerials 2013 to the present day.
 
One thing I did not notice till I downloaded the pics. One of those 'K' aerials appears to be biased towards Band 1 and the other to Band 3. Note the position of the BBC dipole. John.

In fact looking at post 510 I'm now wondering if there should be another band 1 element on the top of the 'Fish Head' making it an 'H'. I thought the bottom section was the connecting wire but looking again it is very straight. Maybe someone has an old catalogue. J.

G6Tanuki 13th Oct 2017 6:46 pm

Re: 405-Line VHF Aerials 2013 to the present day.
 
The "fishhead" in #510 has clearly lost an upper-spine! Perfectly expectable after probably something like six-decades aloft!

Historically there were plenty of combined BI/III antennas which used just a single half-wave BI element [and also expected this to serve as a 3-half-wave receptor for a stack of 'parasitic' BIII elements].

Similarly, often when you come across a combined BI/III array where there are two BI elements they're often a BI dipole-and-director [director being in front of the dipole] rather than the more-sensible Dipole/Reflector [reflector being behind the dipole].

[the "fishhead" does at least look like a dipole-and-reflector for BI - I'm guessing that the designers intended the BIII 'fish-head' loop to be a form of Gamma-match for BI]

I guess that immediately post-WWII in the UK you didn't really need to worry about front:back ratios and directivity because it was unlikely you'd have another BI transmitter 'behind you' on the same channel.

Forward-gain at the expense of rear-rejection.

Refugee 13th Oct 2017 11:13 pm

Re: 405-Line VHF Aerials 2013 to the present day.
 
2 Attachment(s)
The lashings have given over on this one in Doncaster, but at least it has remained on the roof.

Oliver35 14th Oct 2017 12:21 pm

Re: 405-Line VHF Aerials 2013 to the present day.
 
Maybe someone forgot to tell the folks of Guildford when 405 closed down. At least they're Band I/III arrays, so they must know that the war's over!

Oliver

Nuvistor 14th Oct 2017 12:32 pm

Re: 405-Line VHF Aerials 2013 to the present day.
 
Quote:

Originally Posted by Refugee (Post 982663)
The lashings have given over on this one in Doncaster, but at least it has remained on the roof.

Probably posted before but I helped to install many of this type in 1962/63.

Peter.N. 14th Oct 2017 12:47 pm

Re: 405-Line VHF Aerials 2013 to the present day.
 
Excellent selection. I wonder if any of the aerials I put up are still there, in my day it mostly consisted of fitting 'twigs' to existing aerials when ITV at Croydon opened.

When we moved to Charmouth most of the BBC reception was coming from North Hessary Tor or Wenvoe which involved it coming over the hill and descending about 400' into the town - and it did. When Stockland Hill opened on channel 9 the same problem existed although it was only about 10 miles away, when it went UHF you couldn't get a usable signal in most places.

Peter

paulsherwin 14th Oct 2017 2:31 pm

Re: 405-Line VHF Aerials 2013 to the present day.
 
2 Attachment(s)
I snapped this survivor in central Oxford yesterday. It's on top of the Eurobar pub in George Street, on the corner with Gloucester Green bus station. This was the Welsh Pony Hotel in the 60s. The installation is particularly interesting because it perfectly illustrates the difficulties faced by Oxford viewers in the 405 era.

The small UHF aerial is pointed east at Beckley. What's left of the band I aerial is pointing SE towards London, while the band III aerial is pointing NNW towards Lichfield. Those transmitters were 60 and 70 miles away respectively.

The BBC built a relay at Beckley in 1962, but by then people had spent lots of money pulling in a signal from Crystal Palace and didn't want to pay again.

Good reception only arrived in Oxford when Beckley started full UHF services in 1970.

SteveCG 14th Oct 2017 2:57 pm

Re: 405-Line VHF Aerials 2013 to the present day.
 
Re post no 519

A nice example of a Double 9 from Belling & Lee. Note that Belling & Lee increased the boom separation for their designs with increasing element count. This actually gave an increase in forward gain relative to a single boom version! Other manufacturers did not do this. The electrodynamics of multi-element, multi-boom aerials has kept aerial designers in business for years and years.

Indeed Paul and if you go to 'The other place' / Fen Tech (ie Cambridge) you will find a similar profusion of aerials pointing to different transmitters - a riggers paradise!.

By the way did you mean Hannington for VHF? - I thought VHF ITA coverage was 'improved' in Oxford by the opening of the Membury transmitter on Channel B12, Horiz.


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