I've been watching a war film about a plan by the Germans to infiltrate
and sabotage British radar installations. There were lots of shots of
rotating radar aerials - either sweeping backwards and forwards in an
arc or rotating 360 degrees. The action took place in the weeks after
the Dunkirk evacuation (May/June 1940).

When did British radar installations start using rotating dishes, as
opposed to a fixed pair of orthogonal aerials, to determine direction?

Is this an anachronism in the film?

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On Sun 21/08/2022 12:16, NY wrote:

I've been watching a war film about a plan by the Germans to infiltrate
and sabotage British radar installations. There were lots of shots of rotating radar aerials - either sweeping backwards and forwards in an
arc or rotating 360 degrees. The action took place in the weeks after
the Dunkirk evacuation (May/June 1940).

When did British radar installations start using rotating dishes, as
opposed to a fixed pair of orthogonal aerials, to determine direction?

Is this an anachronism in the film?

Have a look at
https://www.subbrit.org.uk/categories/radar/
which will probably answer your question. In particular look at
Ravenscar (may need a bit of searching) and Bempton sites as they used different frequency bands and methodology.

IIRC the first rotating (microwave) radar station was a German
installation near a country house somewhere on the peninsular north of
Le Havre which a team of wartime specialists (SOE and others) took over
and returned the radar equipment to the UK - ISTR they even made a film
about it.

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On 21/08/2022 12:16, NY wrote:

I've been watching a war film about a plan by the Germans to infiltrate
and sabotage British radar installations. There were lots of shots of rotating radar aerials - either sweeping backwards and forwards in an
arc or rotating 360 degrees. The action took place in the weeks after
the Dunkirk evacuation (May/June 1940).

When did British radar installations start using rotating dishes, as
opposed to a fixed pair of orthogonal aerials, to determine direction?

Is this an anachronism in the film?

Rotating antenna were used quite early in WWII. Just looking at a
picture in Latham & Stobbs of a GCI unit at Sopley in 1940 with separate
Tx and Rx antenna on trailers - both rotatable but not not full 360° and
the two had to be kept in sync.

There are lots of pictures of CHL with rotable antenna around 1940

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Woody <harrogate3@ntlworld.com> wrote:

[...]

IIRC the first rotating (microwave) radar station was a German
installation near a country house somewhere on the peninsular north of
Le Havre which a team of wartime specialists (SOE and others) took over
and returned the radar equipment to the UK - ISTR they even made a film
about it.

This was the Bruneval Raid on 27 February 1942; for a definitive account
see: "Most Secret War" by R.V. Jonees. The installation they raided
wasn't by any means the first German radar, it was just one of a chain
of radar sites that had been in existence for some time. The Germans
had developed microwave radar in the late 1930s, but the dishes were
slowly steered to pick up and follow a target and didn't actually
rotate.


--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

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On 21/08/2022 14:43, MB wrote:

On 21/08/2022 12:16, NY wrote:

I've been watching a war film about a plan by the Germans to infiltrate
and sabotage British radar installations. There were lots of shots of
rotating radar aerials - either sweeping backwards and forwards in an
arc or rotating 360 degrees. The action took place in the weeks after
the Dunkirk evacuation (May/June 1940).

When did British radar installations start using rotating dishes, as
opposed to a fixed pair of orthogonal aerials, to determine direction?

Is this an anachronism in the film?

Rotating antenna were used quite early in WWII.  Just looking at a
picture in Latham & Stobbs of a GCI unit at Sopley in 1940 with separate
Tx and Rx antenna on trailers - both rotatable but not not full 360° and
the two had to be kept in sync.

There are lots of pictures of CHL with rotable antenna around 1940

Ah, so CHL was a lot earlier than I realised. My grandpa worked at Danby
which was Chain Home, rather that Chain Home Low. The antennae in the
film did look like the CHL photo
https://i.postimg.cc/Z5rNcm1J/bempton.png in the Bempton article on SubBritannica that was linked from Woody's link https://www.subbrit.org.uk/categories/radar/. I thought it *would* be well-researched since radar featured a lot in the film, but I wanted to
check because it seemed early for rotatable aerials.

I've seen the remains of the buildings at Bempton (just a few miles from
where I live) when we went to the bird-watching cliffs, but I hadn't
realised that there was a radar site at Ravenscar as well. I presume it
was on the flat ground between cliff edge and the square where the
railway station was.

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Plenty of information here

https://www.radarpages.co.uk/index.htm

"It is a testament to the huge efforts of the scientists, engineers and technicians that the entire Home Chain, comprising of CH, CHL and CHEL equipment, was complete by the end of 1943."

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On 21/08/2022 17:39, NY wrote:

Ah, so CHL was a lot earlier than I realised. My grandpa worked at Danby which was Chain Home, rather that Chain Home Low. The antennae in the
film did look like the CHL p

The German equipment was typically very well built but the RAF did a lot
of work on how they would process the data.

An American wrote an article that was very critical of Chain, calling it
crude which it was in some ways but it worked.

It was pointed out that the Americans were given access to the British technology and experience and it was asked if they had had a single
Chain Home site on Hawaii with trained staff then would 'Pearl Harbour'
have ever happened?

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Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:

Woody <harrogate3@ntlworld.com> wrote:

[...]

IIRC the first rotating (microwave) radar station was a German
installation near a country house somewhere on the peninsular north of
Le Havre which a team of wartime specialists (SOE and others) took over
and returned the radar equipment to the UK - ISTR they even made a film about it.

This was the Bruneval Raid on 27 February 1942; for a definitive account
see: "Most Secret War" by R.V. Jonees. The installation they raided
wasn't by any means the first German radar, it was just one of a chain
of radar sites that had been in existence for some time. The Germans
had developed microwave radar in the late 1930s, but the dishes were
slowly steered to pick up and follow a target and didn't actually
rotate.

Two corrections:

Typo: "R.V. Jones"
The German Würzburg radar was not microwave, it worked at around 500
Mc/s.

Lots more information at Arthur Bauer's website:
https://www.cvandt.org


--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

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I don't know, but the creation of really short wavelength transmissions
using magnetrons was the turning point. I remember in the 1950s Deca had
radar vans with rotating aerials which had a parabolic one plane aerial that rotated. They were of course still using high persistence phosphors and synchronised aerials and beam scanning on the screen, nothing too fancy.

Brian

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"NY" <me@privacy.net> wrote in message news:HNCcnXzNQsV1jp_-nZ2dnZfqn_rNnZ2d@brightview.co.uk...

I've been watching a war film about a plan by the Germans to infiltrate
and sabotage British radar installations. There were lots of shots of rotating radar aerials - either sweeping backwards and forwards in an arc
or rotating 360 degrees. The action took place in the weeks after the
Dunkirk evacuation (May/June 1940).

When did British radar installations start using rotating dishes, as
opposed to a fixed pair of orthogonal aerials, to determine direction?

Is this an anachronism in the film?

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I also recall that in the Navy they had a lot of problems in choppy seas, as they reflected the radar randomly adding to clutter which meant real ships could not always be seen. Then somebody thought of a way to do away with
any reflection that changed faster than a ship could move, removing a lot of the spurious crap.
Brian

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This newsgroup posting comes to you directly from...
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briang1@blueyonder.co.uk
Blind user, so no pictures please
Note this Signature is meaningless.!
"Brian Gaff" <brian1gaff@gmail.com> wrote in message news:tdvhcd$2kja0$1@dont-email.me...

I don't know, but the creation of really short wavelength transmissions
using magnetrons was the turning point. I remember in the 1950s Deca had >radar vans with rotating aerials which had a parabolic one plane aerial
that rotated. They were of course still using high persistence phosphors
and synchronised aerials and beam scanning on the screen, nothing too
fancy.

Brian

--

--:
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...
briang1@blueyonder.co.uk
Blind user, so no pictures please
Note this Signature is meaningless.!
"NY" <me@privacy.net> wrote in message news:HNCcnXzNQsV1jp_-nZ2dnZfqn_rNnZ2d@brightview.co.uk...

I've been watching a war film about a plan by the Germans to infiltrate
and sabotage British radar installations. There were lots of shots of
rotating radar aerials - either sweeping backwards and forwards in an arc
or rotating 360 degrees. The action took place in the weeks after the
Dunkirk evacuation (May/June 1940).

When did British radar installations start using rotating dishes, as
opposed to a fixed pair of orthogonal aerials, to determine direction?

Is this an anachronism in the film?

--- SoupGate-Win32 v1.05
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