30th Apr 2016, 7:14 pm | #41 |
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Re: Early Air Ministry oscilloscope type 11.
I think it was the Radar AA System Mk1. Called "ELSIE" back in the early 40's I think. Doesn't mention anything about AA in the AP.
Humphrey's thread & the IWM article relate to a more modern scope & AA System from the 50's. Then along came Bloodhound Missile Batteries which made "Ack - Ack" obsolete. Regards, David |
30th Apr 2016, 8:20 pm | #42 |
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Re: Early Air Ministry oscilloscope type 11.
Well done David . That is it! Please pass my thanks to Alf.
It does seem to have intended as a simple scope for use when the higher performance of the type 7 oscilloscope wasn't necessary. I would have expected it to have been produced in significant quantities but the serial numbers we have suggest that this wasn't the case. They don't seem to have appeared in large quantities on the surplus market. I'm interested to see that the knobs fitted are like the Bulgin pointer knobs fitted in most positions on my unit rather than the more traditional RAF type pointer knob. I note that 'V8' is not marked. Somebody must have explained to the draughtsman that pilot lamps are not classified as valves in spite of the filament and glass envelope . Edward Last edited by Brased; 30th Apr 2016 at 8:34 pm. |
1st May 2016, 11:11 am | #43 |
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Re: Early Air Ministry oscilloscope type 11.
Folks, more pictures. David
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1st May 2016, 11:40 am | #44 |
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Re: Early Air Ministry oscilloscope type 11.
David,
Many thanks for these scans! Whist it is a very basic instrument, it was obviously 'fit for purpose' in its intended application, and well worth restoring and preserving. Andy |
2nd May 2016, 10:35 am | #45 |
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Re: Early Air Ministry oscilloscope type 11.
Remaining pictures. David
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2nd May 2016, 10:36 am | #46 |
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Re: Early Air Ministry oscilloscope type 11.
Last one. David
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2nd May 2016, 1:34 pm | #47 |
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Re: Early Air Ministry oscilloscope type 11.
David,
The scan of the circuit, fig 2, is cropped at the RH side, with two lines going off the page. Should these be joined with a vertical line, so the resistors at the bottom right have one end returned to the HT+ line? Andy |
2nd May 2016, 2:07 pm | #48 |
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Re: Early Air Ministry oscilloscope type 11.
Sorry about that Andy. Seem to have lost 1/4" on the rhs when I had the A3 copy(which Alf had kindly sent) reduced to A4 to fit my cheapo scanner. Actually its just a straight vertical line joining R39 & R12 HT+ wise. David
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2nd May 2016, 2:24 pm | #49 |
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Re: Early Air Ministry oscilloscope type 11.
David, many thanks, I guessed that would be the case.
I'm very pleased the manual turned up - I just need an example of the oscilloscope now to match! On the other hand perhaps not, I've got too many projects for one lifetime as it is. Andy |
2nd May 2016, 5:55 pm | #50 |
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Re: Early Air Ministry oscilloscope type 11.
Amazingly, I've just discovered that I have another wee vintage scope which uses the identical CRT as the Type 11. The E4205/B/7. I raised a thread back on 29th Nov.2014 after acquiring it, but hadn't got round to working on it or tarting it up. Mind you, I acquired it bucksheesh from a vintage chum, and it worked reasonably well after being slowly wound up via a variac. Anyway, removed it from my shelf today, just to re-acquaint myself with a wee valve scope before the Type 11 arrives at the end of the month. Lo & behold - the discovery.
Regards, David Last edited by David Simpson; 2nd May 2016 at 5:56 pm. Reason: spelling |
2nd May 2016, 9:26 pm | #51 |
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Re: Early Air Ministry oscilloscope type 11.
David, thanks for posting all the information. There is now a good chance that my unit will live again although it is at present far from the state when I could safely plug it in. There is evidence of some modification and the rubber insulation on the wiring is brittle. I would also expect to find excessively leaky capacitors as some have been changed already. I don't want to risk damaging components like the mains transformer or choke.
The chassis is rusty and the case damaged so there is quite a bit of work to be done there too. There is also rusting on the front panel along the line of the markings. I would have expected these to have been engraved but I wonder whether some etchant was used which was not properly cleaned off before the paint was applied. It is going to need some work and must take its place in the queue, but there is hope yet. Edward |
11th May 2016, 9:39 pm | #52 |
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Re: Early Air Ministry oscilloscope type 11.
By a strange coincidence one turned up on ebay and I was the only bidder this evening!
The only picture was of the front panel (to be generous, looking its age) so I won't know what it's like inside till it arrives. Andy |
12th May 2016, 11:40 am | #53 |
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Re: Early Air Ministry oscilloscope type 11.
Good for you, Andy. Keep us posted. Regards, David
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26th Aug 2016, 6:34 pm | #54 |
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Re: Early Air Ministry oscilloscope type 11.
Thread reopened at David Simpson's request.
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
26th Aug 2016, 7:29 pm | #55 |
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Re: Early Air Ministry oscilloscope type 11.
I paid a visit to the Air Defence Radar Museum at Neatishead last week and there is one of these oscilloscopes on display but no info about it.
Dave GW7ONS |
26th Aug 2016, 9:05 pm | #56 |
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Re: Early Air Ministry oscilloscope type 11.
Thanks to Graham for re-opening the thread. More thanks to Billy & my son Ian, and Ian's pal Dave for transportation.
This compact wooden cased scope eventually arrived this afternoon. Needs a fair bit of TLC, but hey - this is why we're VRR&R enthusiasts. Right enough Dave, these were used to set up AA Radar equipment. Regards, David Last edited by David Simpson; 26th Aug 2016 at 9:07 pm. Reason: Wrong picture |
3rd Sep 2016, 8:37 pm | #57 |
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Re: Early Air Ministry oscilloscope type 11.
On the mend, at last.
Ref the picture of the underside - several capacitors needed re-soldering. All valves tested ok, 'cept for the SU2150A EHT rectifier. Thankfully, I had a spare. That HT Choke was in a state - the winding had been shorted out, as had the fuse holder. Now repaired by replacing the old tag connections with 8BA wee bolts as connection pillars, and a new paxolin mounted fuse holder fitted. Transformer tested & slowly powered up on my variac. Valves fitted & again a slow power-up - whoopee, a focusable trace on the CRT. HT & EHT a bit low, so will need to delve further. That's it, so far. Hopefully, another progress report soon. Regards, David |
7th Sep 2016, 8:52 pm | #58 |
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Re: Early Air Ministry oscilloscope type 11.
The combination 'Dry Electrolytic Condenser' of 8/16uF for HT reservoir/smoothing was phooked. There is an identical 8/16uF one for de-coupling the screens of the three pentodes. That too was phooked. Also, at installation in the factory, someone had reversed their side-by-side circuit identity. But, worst of all - their 4BA retaining bolts through the chassis were partially blanked off by the long paxolin main tag board underneath(obviously fitted & wired later). 4BA spanners, pliers, and foreceps were useless. So had to make a right-angled spanner out of a small galv. joinery bracket to hold the nut whilst unscrewing the cheese-head bolt from the top side. What a lot of fannying about, but got there in the end.
So far, I've found nothing to identify the manufacturer, but it has a Cossor-ish feel to it. Regards, David |
7th Sep 2016, 10:16 pm | #59 |
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Re: Early Air Ministry oscilloscope type 11.
David,
Don't forget, as I mentioned in post #4, it is referred as an 'Ultrascope' in A.P.2463. Andy |
7th Sep 2016, 11:38 pm | #60 |
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Re: Early Air Ministry oscilloscope type 11.
I suppose, Andy, that during the war & just after, like many other items of military equipment, these scopes were made by several radio companies. Cossor, Ultra, and so on.
Amazingly, every single capacitor & resistor has its circuitry number written on it. Even down to wee 1/4 W resistors & diddy waxies. Particularly the main tagboard underneath - all the components are numbered consecutively L to R - - - C1, C2, R1, R2 - - & so on. Nearly all the wiring is hard drawn tinned copper insulated with coloured & lacquered woven rayon or nylon. On the down side, most joints are excessively wrapped & well blobbed with solder. Needed to tweak up my s-station temp to 380deg, due to heat absorption. Regards, David |