Oscilloscope No11 AA Predictor - UK Vintage Radio Repair and Restoration Discussion Forum

Mister35mm · 22nd Apr 2019, 6:16 pm

Hi there,
I have one of these, can anyone give me some advice as to value
I have not powered it up.

trh01uk · 27th Apr 2019, 7:25 am

Stephen,

I see no-one else is rushing to venture an opinion on this one. I suspect its value is little more than that of the bits inside it, because its going to be part of an AA radar system, and few people are seriously looking at those. Where there is interest, it tends to be limited to WW2 era systems, and this item looks to be 1950s/60s vintage, judging by the knob and connector types fitted.

The IWM confirm this with the comment "Made by AC Cossor. Used by Royal Artillery anti-aircraft guns post 1945." Presumably they will have one then, so no point in offering them a second one!

Confusingly there is an earlier "Oscilloscope Type 11", which was discussed in this thread.

I note there is another picture on the net of one here in a sale. Its obviously a bit of a brute, so is probably taking up a lot of precious space at home?

If you truly want a value on it, then you can't beat the well known auction sites. I would get some good photos, and start an auction at a modest price, and see what interest it generates.

In passing, I would note it helps to have a visual record of these things (the IWM has failed there!), and posting a photo here is one way to make a record of it. A few more photos of the innards would probably be nice.

Richard

M0FYA Andy · 27th Apr 2019, 10:40 am

For some reason I didn't spot this when it was first posted! It intrigues me because I also have one of these things, bought a few months ago on ebay because I thought the value of the parts far exceeded what it cost! On inspection I discovered it had been modified, in some ways rather crudely, but maybe an official 'field mod', certainly not of a 'return to manufacturer' quality, so confirming that I will probably dismantle it. Now the picture Richard links to is fascinating, that unit looks to have the same mod, evidenced by the three shiny knobs at the bottom in place of three fuse-holders. This is one aspect which is rather crude but functional, the knobs belong to potentiometers which have been mounted on aluminium brackets araldited to the chassis.
So either this was a 'standard modification', or my ebay acquisition (which doesn't have the outer case) is the one in the picture!
I still plan to dismantle mine as it's taking up valuable space, unless someone convinces me it is a historical rarity worth preserving in its modified state.

Andy

David Simpson · 27th Apr 2019, 10:43 am

Hello Mr35mm,
If you're interested, you check back through "Search", you'll see that I had a big thread running on restoring a type 11 scope about two years ago. I'd acquired it from "ElectronWillie" originally.
They were rushed into production for the War Dept. for setting up the new radar controlled Ack Ack gun emplacement's predictors after the Battle of Britain. The old mechanical gun predictors were seen to be rather limited during the BoB.
This scope is unique in having a lovely pitch pine wooden case with total copper sheet screening inside. They stayed in use till the early 50's when ground to air missiles came into use.
I think I posted the Manual as a thread attachment, but I have a copy on file somewhere if you ever need it.
It would be interesting to see a Type 11 scope & the Predictor working together.

Regards, David

trh01uk · 27th Apr 2019, 11:16 am

Quote:

Originally Posted by David Simpson

This scope is unique in having a lovely pitch pine wooden case with total copper sheet screening inside. They stayed in use till the early 50's when ground to air missiles came into use.

Haven't you confused the wartime "Type 11" scope - which is certainly in a wooden case - with this one, which is a typical 50s/60s creation - and postwar from both its design and according to the IWM comment?

Richard

David Simpson · 27th Apr 2019, 1:39 pm

Right enough Richard, Stephen's piece of equipment also incorporates a CRT. The cursor scaled in distance & elevation, no doubt. Why the post war MoD called it a Type 11 I don't know. My old Air Ministry Oscilloscope Type11 was just used to set-up & calibrate the original wartime predictor, not actually be part of the fledgling radar AA system.
It might be worth your while, Stephen, contacting VMARS & see if any of their vintage radar buffs can throw some light on this query.

Regards, David

ms660 · 27th Apr 2019, 2:07 pm

It's a No. not Type, it was discussed in this thread:

https://www.vintage-radio.net/forum/...ad.php?t=73529

Lawrence.

ms660 · 27th Apr 2019, 2:44 pm

Some internal shots here:

https://www.siwe.be/files/collectie/...-MK1-200pi.pdf

Lawrence.

David Simpson · 27th Apr 2019, 4:21 pm

I tried the siwi & the IWM site links, but couldn't open the pictures. Does anyone know of a definitive Royal Artillery diagram or picture or a Manual of the whole Radar controlled AA setup ?
I don't think that every AA Radar site had an Oscilloscope Type 11. Probably a RA artificer was responsible for 20 or 30 sites & carried his wooden cased scope around in a van or jeep, testing & calibrating as need be.
What Stephen has is just one item of a racked radar system, I reckon. There must have been a large loom of cabling, linking servo's/desynn's/whatever in the radar antenna - to the predictor, then on to gun's electro/mechanical machinery.

Regards, David

22nd Apr 2019, 6:16 pm	#1
Mister35mm Diode Join Date: Apr 2012 Location: London, UK. Posts: 3	Oscilloscope No11 AA Predictor Hi there, I have one of these, can anyone give me some advice as to value I have not powered it up. Attached Thumbnails __________________ Stephen G7VFY 07956-544202 Last edited by AC/HL; 22nd Apr 2019 at 8:52 pm. Reason: Forum rules

27th Apr 2019, 7:25 am	#2
trh01uk Octode Join Date: Nov 2010 Location: Ross-on-Wye, Herefordshire, UK. Posts: 1,654	Re: Oscilloscope No11 AA Predictor Stephen, I see no-one else is rushing to venture an opinion on this one. I suspect its value is little more than that of the bits inside it, because its going to be part of an AA radar system, and few people are seriously looking at those. Where there is interest, it tends to be limited to WW2 era systems, and this item looks to be 1950s/60s vintage, judging by the knob and connector types fitted. The IWM confirm this with the comment "Made by AC Cossor. Used by Royal Artillery anti-aircraft guns post 1945." Presumably they will have one then, so no point in offering them a second one! Confusingly there is an earlier "Oscilloscope Type 11", which was discussed in this thread. I note there is another picture on the net of one here in a sale. Its obviously a bit of a brute, so is probably taking up a lot of precious space at home? If you truly want a value on it, then you can't beat the well known auction sites. I would get some good photos, and start an auction at a modest price, and see what interest it generates. In passing, I would note it helps to have a visual record of these things (the IWM has failed there!), and posting a photo here is one way to make a record of it. A few more photos of the innards would probably be nice. Richard

27th Apr 2019, 10:40 am	#3
M0FYA Andy Nonode Join Date: May 2007 Location: Preston, Lancashire, UK. Posts: 2,511	Re: Oscilloscope No11 AA Predictor For some reason I didn't spot this when it was first posted! It intrigues me because I also have one of these things, bought a few months ago on ebay because I thought the value of the parts far exceeded what it cost! On inspection I discovered it had been modified, in some ways rather crudely, but maybe an official 'field mod', certainly not of a 'return to manufacturer' quality, so confirming that I will probably dismantle it. Now the picture Richard links to is fascinating, that unit looks to have the same mod, evidenced by the three shiny knobs at the bottom in place of three fuse-holders. This is one aspect which is rather crude but functional, the knobs belong to potentiometers which have been mounted on aluminium brackets araldited to the chassis. So either this was a 'standard modification', or my ebay acquisition (which doesn't have the outer case) is the one in the picture! I still plan to dismantle mine as it's taking up valuable space, unless someone convinces me it is a historical rarity worth preserving in its modified state. Andy

27th Apr 2019, 10:43 am	#4
David Simpson Nonode Join Date: Mar 2008 Location: Aberdeen, UK. Posts: 2,857	Re: Oscilloscope No11 AA Predictor Hello Mr35mm, If you're interested, you check back through "Search", you'll see that I had a big thread running on restoring a type 11 scope about two years ago. I'd acquired it from "ElectronWillie" originally. They were rushed into production for the War Dept. for setting up the new radar controlled Ack Ack gun emplacement's predictors after the Battle of Britain. The old mechanical gun predictors were seen to be rather limited during the BoB. This scope is unique in having a lovely pitch pine wooden case with total copper sheet screening inside. They stayed in use till the early 50's when ground to air missiles came into use. I think I posted the Manual as a thread attachment, but I have a copy on file somewhere if you ever need it. It would be interesting to see a Type 11 scope & the Predictor working together. Regards, David Last edited by David Simpson; 27th Apr 2019 at 10:50 am. Reason: Add'l info

27th Apr 2019, 1:39 pm	#6
David Simpson Nonode Join Date: Mar 2008 Location: Aberdeen, UK. Posts: 2,857	Re: Oscilloscope No11 AA Predictor Right enough Richard, Stephen's piece of equipment also incorporates a CRT. The cursor scaled in distance & elevation, no doubt. Why the post war MoD called it a Type 11 I don't know. My old Air Ministry Oscilloscope Type11 was just used to set-up & calibrate the original wartime predictor, not actually be part of the fledgling radar AA system. It might be worth your while, Stephen, contacting VMARS & see if any of their vintage radar buffs can throw some light on this query. Regards, David

27th Apr 2019, 2:07 pm	#7
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Oscilloscope No11 AA Predictor It's a No. not Type, it was discussed in this thread: https://www.vintage-radio.net/forum/...ad.php?t=73529 Lawrence.

27th Apr 2019, 2:44 pm	#8
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Oscilloscope No11 AA Predictor Some internal shots here: https://www.siwe.be/files/collectie/...-MK1-200pi.pdf Lawrence.

27th Apr 2019, 4:21 pm	#9
David Simpson Nonode Join Date: Mar 2008 Location: Aberdeen, UK. Posts: 2,857	Re: Oscilloscope No11 AA Predictor I tried the siwi & the IWM site links, but couldn't open the pictures. Does anyone know of a definitive Royal Artillery diagram or picture or a Manual of the whole Radar controlled AA setup ? I don't think that every AA Radar site had an Oscilloscope Type 11. Probably a RA artificer was responsible for 20 or 30 sites & carried his wooden cased scope around in a van or jeep, testing & calibrating as need be. What Stephen has is just one item of a racked radar system, I reckon. There must have been a large loom of cabling, linking servo's/desynn's/whatever in the radar antenna - to the predictor, then on to gun's electro/mechanical machinery. Regards, David