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View Full Version : Anyone know what these guys are testing???? - any information please.jpg (1/1)


Waldo
July 3rd 07, 12:41 AM

Ray O'Hara[_2_]
July 3rd 07, 02:09 AM
"Waldo" > wrote in message
...

radar.

Neil Hoskins
July 3rd 07, 08:26 AM
"Ray O'Hara" > wrote in message
...
>
> "Waldo" > wrote in message
> ...
>
> radar.
>

Yes, the Germans never figured out the cavity magnetron so for airborne
radar they had to muck around with arrays. Remember the old Airfix model of
the Uhu with the aerials on the nose? They were a bugger to get straight
while the glue was still soft.

Waldo
July 3rd 07, 10:32 AM
>Yes, the Germans never figured out the cavity magnetron so for airborne
>radar they had to muck around with arrays.

While they never did figure out the magnetron, they did capture one
that lead hem to develop a copy of it when they shot down a Stiling
with H2S. Toward the end of the war they did field upwards of ten AI
Radars on Junkers aircraft called the Berlin RADAR that operated in
the centimeter wavelength.

I am not so sure that the picture that I posted is a test radar. These
kind of things really but me when I don't learn the answer for
certain.

Waldo,.

Jake
July 3rd 07, 11:50 AM
On Tue, 03 Jul 2007 09:32:33 GMT, Waldo wrote:

>>Yes, the Germans never figured out the cavity magnetron so for airborne
>>radar they had to muck around with arrays.
>
> While they never did figure out the magnetron, they did capture one
> that lead hem to develop a copy of it when they shot down a Stiling
> with H2S. Toward the end of the war they did field upwards of ten AI
> Radars on Junkers aircraft called the Berlin RADAR that operated in
> the centimeter wavelength.
>
> I am not so sure that the picture that I posted is a test radar. These
> kind of things really but me when I don't learn the answer for
> certain.
>
> Waldo,.

Those look like hoses to me, if they were waveguide they would be much
higher frequency than any one was using at the time or for a long time
after WW2.

JakeInHartsel

Jake
July 3rd 07, 12:55 PM
On Tue, 3 Jul 2007 04:50:06 -0600, Jake wrote:

> On Tue, 03 Jul 2007 09:32:33 GMT, Waldo wrote:
>
>>>Yes, the Germans never figured out the cavity magnetron so for airborne
>>>radar they had to muck around with arrays.
>>
>> While they never did figure out the magnetron, they did capture one
>> that lead hem to develop a copy of it when they shot down a Stiling
>> with H2S. Toward the end of the war they did field upwards of ten AI
>> Radars on Junkers aircraft called the Berlin RADAR that operated in
>> the centimeter wavelength.
>>
>> I am not so sure that the picture that I posted is a test radar. These
>> kind of things really but me when I don't learn the answer for
>> certain.
>>
>> Waldo,.
>
> Those look like hoses to me, if they were waveguide they would be much
> higher frequency than any one was using at the time or for a long time
> after WW2.
>
> JakeInHartsel

I have seen pictures of somewhat similar setups used for testing deicing
equipment. The deicing equipment being on a plane following the one with
the spray setup.

JakeInHartsel

miket6065
July 3rd 07, 11:58 PM
I think you are on to it here. It looks like snow on the ground. The techs
all look civilian instead of military. They might be testing the deicing
boot on the tailfins?

Waldo
July 4th 07, 04:42 AM
Turns out the mystery is solved.

An answer was supplied to myself on another board by a participant
with the handle of Heliopause

The image originated in a German propaganda magazine dating from
January 1941 called Der Adler.

Turns out there was a caption on the page that I didn't think was
associated with the image. (I read and translated every damn thing on
the page EXCEPT for the crucial caption. DOH! Here is the caption and
the rough translation.

Zum bilden unten: Um stromungsgeschwindigkeiten und anströmrichtung am
leitwerk des flugzeugs zu messen, wird ein grosser verspannter mast
mit zahlreicher messdüsen, scherzhaft "weihnachtbaum" genannt,
angebracht. Von den düsen führen rohrleitungen nach dem manometerbrett
vorn in bezatzungsraum.

Roughly this means:

To measure (air)flowspeeds and flowdirection at the tail of the
airplane a big mast is attached with numerous measurement equipment,
nicknamed "Christmas tree". From the openings pipes lead to the
manometerplate in the cockpit.

So unless the caption is an effort at wartime deception - that appears
to be the answer!

I had also though of another possibility, that perhaps it was some
sort of equipment for laying smoke. I have seen such equipment on a
Stuka and on a P-38. But it appears not.

Thank you all for trying with your suggestions.

Waldo.


P.S. About waveguides. I didn't think that they were waveguides, but
did think it possible that they were insulated wiring. The cabling of
the period was quite robust. But I guess not.

Charlie[_5_]
July 4th 07, 10:45 PM
The technology of the time would indicate radar for night fighter use. The
signal, radio frequency energy, would have been carried to the radiating
units, the small three prong things, by a wire. The wires were enclosed
in a metal tube or jacket up to the radiating element. The last part was
apparently a rigid copper or steel tube meeting the requirements of the
engineering design. The radiator extended from that. The wire was inside
the shielding to prevent stray radiation. The row of radiating antenna
assemblies would have created a directional signal. There are other things
that would have made the signal more directional but drag and weight quickly
becomes a large factor, especially in aircraft of that era. Don't think in
terms of contemporary electronics. Think in terms of rather large vacuum
tubes and antenna systems closer in design and technology to a big TV
antenna on the roof.


"Waldo" > wrote in message
...

Waldo
July 5th 07, 04:23 AM
Charlie

Thanks for your post. I am well aware what the physical qualities,
tubes etc. that a RADAR of the period had.

In fact I have been researching the topic (with an eye toward writing
a book on the AI Radars of the war) for a couple of years now doing my
best to use original training documents, and "Notes on the use of
material", or manuals which were often not produced at all.

Anyway I though I may comment on your description of a wave guide. The
description I will quote is from a great little obscure book called
The Radar Army bt Reg Batt page 44.

"The next question was how to transfer this power to an aerial.
Coaxial cables of the type and quality then in existence were
considered too lossy. The possibility of using a waveguide was
considered. This was a whole new untried technique. The waveguide
consisted of a hollow metal tube having a critical diameter along
which the short radio waves could be propagated. It was decided to try
one.

We needed several yards of metal tubing of about two inches diameter
which for the purpose of the experiment was sufficiently close in
terms of wavelength to what was required. At the time we were given to
understand that we had acquired house gutter piping (in those days
zinc) bought from Edgar's ironmongers' shop in Swanage. But many years
later I was to learn from Jimmy Atkinson that it was vent piping
belonging to Elsan chemical toilet kits. These were stocked in main
stores, Elsans being the necessary form of sanitation at the Worth
Matravers site. It was a typical example of the Atkinson flair for
procurement, but since a number of kits had to be drawn in order to
provide sufficient piping, he was left with a somewhat bizarre
problem. The fact that we knew nothing of this at the time was
doubtless in order not to offend the sensibilities of those involved
with the experiment!"

All you need is some plumbing!

Waldo.

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