Directional Antenna?

[dominicbeesley]

Hello, here's another gem from the junk pile, before I break it up for bits what is it and is it of any use to anyone? I'm guessing it's some sort of directional antenna (radar?).

It's marked 10B/16422 - BTW is there an online resource for looking up these services part numbers, I've not found anything by Googling, but again not knowing what the words are is a bit of a hindrance!

Cheers

Dom

....So far I've just loaded up my third car-load of rubbish for the tip but still haven't made enough room for the one car-load of stuff I bought at the weekend. I must have some sort of inverse Tardis effect in the cellar where things seem bigger inside!

[KeithsTV]

Could it be a Leigh Light as fitted to Coastal Command aircraft in WW2?

Here's a picture of one from the Secret War book/TV series from the 70s.

Keith

[dominicbeesley]

Hello Keith,

I wish it were! It's about half the diameter and there doesn't appear to be any light source. Attached is a picture of the stuff inside the perspex "bulb".

Dom

[russell_w_b]

Originally Posted by dominicbeesley

Hello Keith,

I wish it were! It's about half the diameter and there doesn't appear to be any light source. Attached is a picture of the stuff inside the perspex "bulb".

Dom

Is that a silvered parabolic mirror behind? Did I see a BNC connector underneath?

[peter_scott]

If there are any other numbers on parts in it then you might find something here:

http://www.wbparts.com/search.cfm

[dominicbeesley]

Russel, the bit behind is the view through my window - both sides are covered with a perspex bulb, I'll try and get a side-on shot tomorrow.

Thanks peter for the reference, I'll have a look

Cheers

Dom

[Skywave]

I'm going for a wild guess on this.

Looking at :

(a) the large size of the glass, which is shaped like a lens;
(b) the machinery - seen through the glass - it looks like it is designed to have some sort of rotation of movement;
(c) and the Jones connectors, which imply low-frequency connections -

could this be some sort of light signalling device - or maybe even the light source from a WW2 Lancaster bomber as in the famous Dam Busters Raid?

Al / Skywave

[dominicbeesley]

Hi Al,

I'm pretty sure it's not a light, but some sort of aerial. The "loop" around the glass - not really obvious on the pictures is about 2" wide and 3/4" thick. It's also marked:

"LOOP MAY BE ROTATED BY HAND
ONLY WHEN SWITCHED ∞ POSITION.
TO AVOID DAMAGE TO GEARS - ROTATE SLOWLY."

And has a stamp with a large red "R" on a white circle with Mar 1951 underneath.

Inside the perspex bulb there's a set of brushes that take conenctions to the loop. In the middle there is a black painted metal cap over what looks like some kind of large wire-wound potentiometer and lots of small screw adjustments.

On the base there's a three-wire moto fed via a small transformer or choke.

Dom

[russell_w_b]

Originally Posted by dominicbeesley

Hi Al,

I'm pretty sure it's not a light, but some sort of aerial. The "loop" around the glass - not really obvious on the pictures is about 2" wide and 3/4" thick. It's also marked:

"LOOP MAY BE ROTATED BY HAND
ONLY WHEN SWITCHED ∞ POSITION.
TO AVOID DAMAGE TO GEARS - ROTATE SLOWLY."

And has a stamp with a large red "R" on a white circle with Mar 1951 underneath.

Inside the perspex bulb there's a set of brushes that take conenctions to the loop. In the middle there is a black painted metal cap over what looks like some kind of large wire-wound potentiometer and lots of small screw adjustments.

On the base there's a three-wire moto fed via a small transformer or choke.

Dom

Could be some sort of goniometer (direction-finding) device with a 'Selsyn' or 'Magslip' driver arrangement, and the presence of a potentiometer suggests positional feedback indication.

Is there a waveguide or some other sort of RF connector on it?

[Mark_4CX35000]

For it to be an antenna, there must be a signal output of some kind
which will be used to drive later circuits.

Is the somesort of RF socket on it?
Have you turned the gears to see what happens inside ?
What does the numbers read on the dial inside ?

The daft things is, I have seen something like this before, but I cannot
recall what it was used for.

[dominicbeesley]

There's no RF connectors other than the two jones plugs and one jones socket.

The little wheel inside is marked 20,10,0,10,20 on each semi-circle with an adjustment that moves a pin along the centre line, to make an adjustable cam. This moves a paxolin arm that goes into the black cap, purpose unknown but I'm guessing it gives a slight advance/retard to the potentiometer?. This arm swings by about 1/16" during a rotation relative to the loop.

The motor is coupled via a few gears on to the bottom to the loop via a collar on an axle, there's a gear on the collar inside that drives the little wheel a twice the rotational speed of the loop.

(Sorry for my rubbish description!)

It's certainly an intriguing thing! If I could work out the motor arrangement maybe I could rig it up as a directional roof aerial for my bus to help pick up R4 Long Wave on the drive down to Le Mans next year!

Dom

[russell_w_b]

Originally Posted by dominicbeesley

It's certainly an intriguing thing! If I could work out the motor arrangement maybe I could rig it up as a directional roof aerial for my bus to help pick up R4 Long Wave on the drive down to Le Mans next year!

Dom

What is the resistance of the loop when measured at the brushes? Does the loop contain many turns of wire or is it a solid thing? No marks in degrees, I see. Are you sure there're no other markings of any description on this mysterious object (which is now intriguing me as well!)

Could be owt, really...

[HMV 1120]

Looking through another source 10B is the prefix for ' (Wireless and Radar) Aerial and mast equipment and insulators'

10BB is specifically radar equpiment, hence this is probably part of some DF equipment?

Sorry, nothing more specific this end.

Regards, Robs

[Mark_4CX35000]

Originally Posted by dominicbeesley

There's no RF connectors other than the two jones plugs and one jones socket.

The little wheel inside is marked 20,10,0,10,20 on each semi-circle with an adjustment that moves a pin along the centre line, to make an adjustable cam. This moves a paxolin arm that goes into the black cap, purpose unknown but I'm guessing it gives a slight advance/retard to the potentiometer?.

Dom

The more I look at it, the more I think industrial control or the control of
multiple generators in a large factory. Certainly looks to be control panel
mounting, and with those numbers on the dial it looks as if it is a
Synchroscope.

I did think it was a Power Factor meter, but the numbering is wrong.

[XTC]

The size of the loop aerial would suggest UHF, but as Al said, Jones plugs aren't compatible with that. Is there any circuitry inside such as acorn valves, or even just a detector? Why the polished reflector if it isn't optical?

My guess is that this is part of a radio landing system or at least something to do with navigation.

Pete.

[dominicbeesley]

Hi Pete,

There isn't a reflector that was just my rubbish photography! Both sides are clear perspex. I'll take it apart when I'm back after the weekend to see if there's any electronics but I'd say probably not, the black cap isn't really big enough to fit much inside.

I did wonder if it was some kind of VHF or possibly even MF "four-course" aerial but can't find any pictures of these to compare...

Cheers

Dom

[beamcurrent]

Hi Dom

Don't break them up I have the radio that they work with.

PM following

beamcurrent

[beamcurrent]

HI All

Further to my previous post here are some pictures of the loop and it's associated equipment.
Picture 1 is the racking system, very hard to find with the 19Volt regulator at the end.
Picture 2 is of my Rx. there are no controls on it, they are on the remote box pic. 4
Pic 3 is the loop and the compass display meter.

The set runs from 24-28 volts with a rotary converter, the 19 volt regulator is the heater supply, and it needs a 400Hz ac supply for the servo motors.

There are lots of options with this set and still a good few bits to track down.

Need to find the handbook for it as well, I do have a copy of the circuit, but not the interconnections.

regards

Beamcurrent