EMI 2005 Manuals

[andypilgrim]

Hi Everyone,
Ive acquired a pair of EMI 2005 camera chains, both have been in storage for decades. They are complete chains with lenses, loads of cables, control panels etc etc etc. I am beginning the restoration of these heavy bits of broadcast technology. I'm making slow but steady progress on the basics, name power supplies which I've recapped and repaired both, and now moving deeper in to the CCU's and cameras.
I've pulled the tube assemblies and checked the optics which all look good so the project is worth pursuing.

What I need are manuals for the things, I am currently working blind and considering that have got a fair way, I've focused on one camera and I can scope 3 outputs on the camera colour boards but only two appear at the CCU input boards, this is not a cable fault as I have a number of cables which all give the same result. I have two coloured 'blobs' o the monitor which I can move about and change the shape of with various line up controls on the CCU, clearly I have either a scanning or electrode voltage fault. along the way has been a lot of capacitor replacement as they have failed. The two cameras appear slightly different in that one seems to have had a number of modifications to both the camera and CCU making board swapping unlikely to work, or more likely just confuse the issue.

If anyone has manuals for these cameras that they could spare I am looking to beg, borrow or buy them, whichever works. I also have an Ampex HS-100C slow motion recorder that I am looking for manuals for. A lot of these circuitry is similar to the EMI2001 camera so manuals for this could also help.

Any help would be greatly appreciated, I'd like to get these going rather than just put them back in to storage to deteriorate further.

[PaulM]

Hello Andy,

We have the manuals for the EMI 2005 in our Broadcast Engineering Museum library.

Our policy is that we only loan them locally - we can't post them (too risky on several counts from experience), and we can't photocopy (takes way too long for such large manuals).

You are welcome to have them for local photocopy near our museum near Gainsborough. You would also be able to see our example of the same camera!

If you visited on our Heritage Open Days in September, we could make them available.

See: https://becg.org.uk/2023/08/21/herit...s-2023-update/

Could that work for you?

Best regards,

Paul Marshall
Broadcast Engineering Conservation Group
Broadcast Engineering Museum.
www.becg.tv

[andypilgrim]

HI Paul,
Thank you for that offer, maybe if it is possible I could bring a portable document scanner with me that hooks to a laptop and spend a couple of hours just scanning the most important parts if you could find me a quiet corner to do that. Happy to make a nice donation to the museum for its help. I am going to still keep a lookout for a set of manuals to acquire as well, in case you hear of any.
You were right in your comments on Facebook, I've discovered a hell of a lot about how the camera works and the signal path in the last few weeks. I came to the conclusion that only one camera was ever going to work, and took apart and spread out one of the CCU's so that I could meter out the interconnections sort of reverse engineer it (it will go back together). I also made an extender card for the camera and CCU boards using a damaged extender from my RCA TR-600 (i have a lot of those extenders for some reason and it uses the same pitch connector) I now know what about 60 percent of the camera cable does, how the signal goes through the CCU ( I found some design notes on the internet to assist) and how its processed from the target amps through the camera head itself. What I have discovered is an enormous amount of transistors although technically working as a transistor have gone low gain, very low gain. I've probably now replace 300 capacitors and getting on for 100 transistors. I'm at the point of having 3 coloured blobs on a RGB monitor that are steady, adjustable and come on every time I switch the thing on so I now have to figure out if I have a problem with the scanning or the tube electrode voltages. I found some info on the P8130 ledicons, but not quite enough. It's a mission but it's quite interesting as well the components are all pretty much standard cheap parts and readily available. The reason one of the cameras will never work is that its viewfinder EHT transformer arcs over as its insulation has failed and one of the lenses is missing two of the servo modules. Still it makes a change from wrestling with timebase correctors in tape machines !!

[PaulM]

Hello Andy,

You will be made very welcome at our Heritage Open Days on the 9th and/or 10th September. There's going to be a lot to see! As a 'fellow traveller' I'm sure that you will find things of interest.

We have lots of rooms, including our nascent library which is quiet and has space. A decent camera works quite well for copying the pull-out 'long' schematics. We have a standard A4 scanner up there for normal pages, if that helps. Tea and coffee on hand!

The quality of EMI components was always an issue in their broadcast kit. The earlier valve based black and white Image Orthicon 203 was almost a scandal with its Wima capacitors that all had to be replaced quite early on its operational life.

We will be posting more information about the event soon, but there's still a lot of threads coming together.

Best regards,

Paul M
BECG
www.becg.tv

[andypilgrim]

Big progress this week, having solved a few little problems resulting from broken cables in the CCU card connectors and a wayward power supply that would slowly cycle the 18volt CCU feed up and down I narrowed my problem Of just having three blobs on the screen down to the focus circuit. All three focus controls on the CCU worked to a small degree but in the power supply there is a control for focus current, this did precisely nothing.
So, with a pencil and paper and a multimeter I figured out what this part of the circuit did and where it connected to the camera and with that knowledge found a power transistor open circuit. With a new (nearly equivalent) replacement I e managed to focus the tubes and got the first (poor) pictures on the camera. There’s a long long way to go but it’s a step in the right direction.
Whilst this is all a bit of a folly it feels like a great achievement every step forward, especially as I’m still working blind without manuals.
The camera is looking at my Quad, the pictures are of the green channel, the red is noisy (target amp probably) and the blue channel is clearly stuck at full gain, the gain control doesn’t work though the control voltage gets to the camera. I can select all three channels on the picture monitor though.

[VTRestorer]

A great achievement.

Well done.

I eagerly anticipate more progress...

Jonathan

[beamcurrent]

hello Andy

Pleased you are making progress, and you have a picture on the viewfinder, not the most reliable area. You do have the advantage that there are 3 of most things, one for each of the RGB circuits.

I did mention earlier that there are a lot of similarities between the 2005 and the 2001. One of these is the aperture corrector, which in the 2001 was an external unit, but brought into the CCU frame in the 2005 as there was space created by their not being a luminance channel.

I believe the circuits and modules are the same, circuits at http://www.tvcameramuseum.org/emi/2001/2001index.html sorry there is not more circuitry available, it's a time problem.

A note on component reliability, you have to look at the problem with the available choices half a century ago. Time has shown some components ( capacitors) have lasted better than others but the designers did not know the true lifespan and there was always cost to consider....

Please keep us posted as to progress.

[andypilgrim]

Inching forwards slowly, this week I concentrated on the RGB output boards as I had little coming from them. Soon found there were no clamp pulses on the test points on all three boards. Metered the clamp pulse pins of the output boards back to one pin of the pulse board and then worked back theiugh the pulse board with my home made extender until I found the clamp pulses to be present at the base of a transistor but not the collector. Popped in a new 2n3904 and bingo we have colour outputs.
It’s hooked up to a better monitor now, and with a bit of adjustment we gave a sort of half decent picture.
The blue width control doesn’t work though the control voltage gets to the camera head (I spent some time figuring out as much of the BIW cable as I could) and the blue gain control also doesn’t work though I know why that is, it’s just a nightmare to fix, however it’s got a lot further than I ever expected it to !

Thank you Brian for the info on the aperture corrector circuits on your 2001 page, the aperture corrector on this one doesn’t work, if you switch it in you lose the green channel so the diagrams will make it a lot easier, it will seem alien to fault find on this project with actual circuit diagrams, so far I’ve done it without.

Pics below of the image so far and my home made setup pattern. And yes I know the rest card is upside down, I’d stuck it on the piece of wood with spray contact adhesive before I realise I’d done it wrong, but for what I’m doing it doesn’t matter. The piece of wood puts the centre of the pattern at the exact same height as the centre of the lens with the camera level.

[PaulM]

Hello Andy,

Failed aperture correctors are a bit of a theme with cameras of this age. There's often issues with the glass delay lines - the transducers stop working or just fall off the block (they're usually glued on). Once the electronics is found to be OK, it's down the delays and they're tricky in terms of spares.

As I've said before, EMI tended to use domestic quality components, so failed plastic transistors and dodgy caps are more prevalent than some other makes.

You are still more than welcome to copy the manuals at our Broadcast Engineering Museum. Indeed, happy to assist with testing the delay lines.

You've done very well so far!

Best regards,

Paul M
BECG
www.becg.tv