EMI Tape Recorder L4A

[Hartley118]

Originally Posted by paulsherwin

They are 10k now, but back in the valve era I'm pretty sure they were mostly 600 ohms both in and out using transformers. At a guess, this recorder will follow that standard.

I suppose that at that time Line might literally have meant a telephone line or PO music circuit, in which case a 600 ohm line termination might have been present in the machine.

Martin

[pmmunro]

Originally Posted by beamcurrent

None the less a very good find and in such nice condition too, I have been on the lookout for one of these for a while to add to my collection.

I would be interested to see a picture of the battery pack if it is still with the machine?

Regards Brian

Brian, Please see private message.

PMM

[Radio Wrangler]

There is already a photo of the battery pack earlier in the thread. It looks like 14V made from a three-cell, another three-cell and a single cell of the little grey 'Sonnenshein' lead-acid batteries enclosed in a 2-part plastic clamshell case.

David

[monaro0162]

I did try to get the top of the machine apart, to gain access to the take up reel belt, but chickened out, because it doesn't seem easy, looks like various levers and springs have to come off first somehow. Will have another go later and will take lots of photos during dismantling so as to remember how to put it back together again.

Re the battery pack, it has an internal unit, as described, presumably charged via the 'external battery' connector? Was there an external battery pack as well? The internal lead-acid battery is tiny, not surprising it didn't last anywhere near the claimed 3 hours!

[paulsherwin]

These machines were primarily designed to record short location interviews, so would only have needed half an hour or so of battery life. They would have been plugged into a charger when the reporter returned to the studio.

[pmmunro]

I have now located a copy of the EMI manual TL1526 "Instruction Manual Portable Tape Recorder Type L4 (Series)" published in July 1966.

It covers Models L4 A, B, C and D, all with NAB variants. Although described as an "Instruction Manual", there are full circuit diagrams, parts lists and servicing instructions. Interior views of the machine are prints of photographs.

The whole manual is about 70 pages, including fold-out pages which allow their content to be read with another page open, and some diagrams roughly A3 size.

As this seems to be quite a rare document, I would like it to be available for anyone who needs it. My L4 is going to Beamcurrent and I want him to have the manual.

If anyone else wants a copy, I would like to suggest that we come to some arrangement whereby one of those interested takes on to scan the manual, or have it scanned, at acceptably high definition and makes it generally available. I don't have a big enough scanner and it will be some time until I could attempt the full scanning, due to other commitments.

PMM

[monaro0162]

One of these recently sold on e-bay. It appears to be a slightly different model, with different microphone connectors. It was sold with an instruction manual too, it looks to be the same manual that pmmunro describes?

Obviously I'm keen to see the operating and servicing instructions on these machines, as I've yet to take mine apart to replace the take up belt, to get it working.

[pmmunro]

Brian, Beamcurrent, has offered to scan the manual for the L4.

I'll be sending this on to him in the next few days and he will need some time to find an opportunity to do the scanning. I will ask him to post a message here when he has made the scan and anyone interested can ask him for a copy.

PMM

[monaro0162]

Thank you PMM.

My unit is a plain L4, no NAB equalisation?

[llama]

Those XLR mic connectors don't look original to me, being too close to their respective labels.
Graham

[beamcurrent]

Thanks to the generosity of PMMUNRO I have now scanned the EMI L4 handbook. This covers models L4 A to C.

The files are too large to have here so the link to them is here:-

http://www.tvcameramuseum.org/emi/st...-l4-index.html

There are 4 files, the text in both small and larger file size, the Figures (circuits) and a figure with some unofficial mods for the C version.

Regards

Brian

[monaro0162]

Beamcurrent and PMMUNRO many thanks for making the document available and its a great quality scan too. Should make fixing my one a little easier. Looks like a fair bit of dismantling will be required to access and change both belts. When I attempted it on mine all the rotating parts were wobbling about and trying to fall out so I put it back together and it all went back bar one small ball bearing that came from somewhere. Thanks again.

[beamcurrent]

I have done a little work on my machine, an L4C, to replace the take-up spool drive belt. I bought one from CPC type "AVBELT113" which is 77mm diameter.

Although it is a square section belt, replacing a round one it does not seem to be a problem. Very fiddley to fit!

Regards Brian

[monaro0162]

Is this the belt that runs the take up reel? How is it running? Yet to replace the belt on the one I have, it also has a hardened rubber idler, and was quite noisy in operation.

[beamcurrent]

The belt is for the take up spool, it does run OK, my feeling is it could be just a little tighter, perhaps to allow for future stretch? as the speed of the take-up spool changes as to how much tape there is on it there must be some slip involved.

The rubber idlers are a harder problem to deal with. the edges of mine are poor, but they seem to work. the one that does the rewind to the feed spool does not grip so well. I had toyed with the idea of painting rubber solution on them, like a sort of tyre. but in the end left them alone. they are quite noisy.

Brian