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Ekco T344 plus another one

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helloekco
(@helloekco)
Trusted V-Ratter Registered

Hi everyone,

A few months ago I acquired a couple of Ekco 405 line sets to kick off my TV restoration hobby, which I'm finally getting around to making a start on. I've dabbled in valve radio repairs / built a couple of valve hifi amplifiers in the past, but this is (almost) my first time on anything with a CRT.

The sets are cosmetically not bad, and before looking closely I thought that they were a pair of T344s, one having the back panel missing. However, one of the sets (the one with the unrestored LOPT shroud!) has a different timebase circuit board to the other, having 3 valves instead of the usual two. I can't figure out what model this could be, from looking at various Trader sheets that I have. The only clue I have is that this page mentions the T344 as having 17 valves or "18 [valves] in fringe models" - what exactly is a fringe model in this context? Please can anyone identify this model?

In case you hadn't guessed, another problem I have (as my ultimate goal is to get both sets working) is that I don't have the correct service data, especially for the 18 valved set. I am a BVWS member and therefore have access to all of their available Trader sheets, however the closest one I have is for the T345, which I've no doubt is similar, but with the addition of VHF radio. My T344s both have quite different main chassis layouts to that given in the Trader sheet for the T345 however (unless of course someone has just placed all the valves in the wrong sockets!). What I'd like to know is, does a specific service sheet exist for the T344?

Thanks in advance,

Chris.

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Topic starter Posted : 16/01/2020 12:08 am
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crustytv
(@crustytv)
Vrat Founder Admin

Hi and welcome to Radios-TV Vrat forum,

Posted by: @helloekco

Please can anyone identify this model?

As you've discovered there are two models of the T344, both released in April 1959, the T344 and the "Fringe" version T344F (the set you're trying to identify). Essentially the T344F is the same as the T344 but with some component variances, plus the additional valve for "Fly-Wheel Sync" and its associated, additional circuitry.

Posted by: @helloekco

what exactly is a fringe model in this context?

"Fringe", meaning the TV set was to be owned and operated at the fringe of the reception area, as such a T344 would not be suitable. Therefore, a T344F would have been required, it has the additional circuitry known as "Fly-Wheel Synchronisation" to improve on the fringe signal, this is your additional valve and its associated circuitry.

Note: Today with the owner providing essentially their own local transmitter, an Aurora, hedghog, dinosaur standards convertor, "fringe" is now a non-entity. As such an owner with a "fringe" TV set will find they need to attenuate the signal as the set will likely be swamped by the provided signal thinking its sitting under the transmitter.

I suggest if you've not already done so pick up a copy of "Television Receiver servicing" By E.A.W. Spreadbury. An excellent book which is a must-read for anyone attempting to understand 405 television theory. Vol 1 covers Time base circuits, Vol 2 covers Receiver and Power supply. Volume 1, Chapter 10 has 14 pages dedicated to fully explaining how fly-wheel sync works. The books assume a basic level of pre knowledge gained on radio servicing. Spreadbury can be sourced from Amazon, prices vary.

Posted by: @helloekco

What I'd like to know is, does a specific service sheet exist for the T344?

Back to the matter in hand and your final query, EKCO may well have produced a manufacture's data card for the T344F. I don't think I have it but will check as I do have a whole raft of EKCO data cards in stock but cannot remember if the T344F is included.

However, not having access to the EKCO manufacturers data is not essential or a show stopper. The T344 Trader sheet service data you already have is pretty much all you need for 95% of the TV's circuitry. The additional 5%, the Fly-wheel sync circuit data, is covered in a supplement. Attached below is that relevant additional circuitry data for the T344F fly-wheel sync, not covered by your Trader sheet. Armed with this you should be able to comfortably repair the TV.

Hope all the above helps and I/we look forward to you sharing the repair progress and photos on the forum ? 

flywheelt344f

Additional Note: EKCO Ferranti T1023F also used the same fly-wheel circuit

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Posted : 16/01/2020 8:29 am
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Cathovisor
(@cathovisor)
Illustrious V-Ratter Registered

I'd echo (sorry) what Crusty has said regarding Spreadbury - it's surprisingly readable too: my own preference for sourcing copies online is AbeBooks - there are a few copies on there at the moment. It does also turn up at BVWS meetings and amateur radio rallies.

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Posted : 16/01/2020 12:30 pm
helloekco liked
PYE625
(@pye625)
Famed V-Ratter Registered

Hi Chris, I will be looking forward to following your restoration of these two Ekco's.

I repaired a T370 a couple of years ago, it may have similarities to the chassis in your models. It took quite a bit of work to bring it back to good health....

https://www.radios-tv.co.uk/community/black-white-tvs/ekco-t370/

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Posted : 16/01/2020 6:15 pm
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Nuvistor
(@nuvistor)
Famed V-Ratter Registered

Was the T1023F an Ekco, I thought that number scheme was Ferranti but yes the same chassis.

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Posted : 16/01/2020 7:11 pm
Nuvistor
(@nuvistor)
Famed V-Ratter Registered

Ekco would have unlikely produced a new manual for the Fringe version, like the Trader sheet it would have been an addition, probably just one sheet to keep with the standard manual.

 

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Posted : 16/01/2020 8:27 pm
Till Eulenspiegel
(@till)
Famed V-Ratter Registered
Posted by: @nuvistor

Was the T1023F an Ekco?

Hi Frank,  the Ferranti models T1023 and T1023F are electrically identical to the Ekco T344 and T344F respectively.  Only the cabinet presentation differs. Information for these sets  can be found in the 1959/60 Radio and Television servicing book.

Till Eulenspiegel.

  

 

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Posted : 16/01/2020 9:35 pm
helloekco
(@helloekco)
Trusted V-Ratter Registered

@crustytv Thanks for that, I'm immensely grateful. I've already ordered both volumes of Spreadbury, that sounds like exactly what I've been looking for online.

I had heard of flywheel sync but didn't know exactly what its purpose was. I look forward to reading all about it.

@Cathovisor thanks for the recommendation for AbeBooks, I hadn't heard of them. There are some really low prices on there.

@PYE625 Your set's chassis looks almost identical to the T344, I'll have a good read through your thread. I don't think I've seen it already in my online research.

Thanks everyone. I think I'll try and get hold of that 1959/60 Radio and Television servicing book, as the Trader sheet I have is for the T345 not T344. The circuit differences might not be that great, but the component positions are different on the chassis (well, the valves anyway).

As I mentioned, I have had the sets for a while already and when I initially got them I did try gradually powering them up with a variac. I know nothing about the history of them and I was hoping in vain to not even need to remove the chassis from the cabinets, so I just thought I'd see what was what. After snipping the wax caps that I could see on the rear of the chassis, the T344's heaters all lit, but it started to produce smoke from somewhere on the front of the chassis that I couldn't see, so was promptly turned off. The T344F warmed up without incident but the timebase made a very off-pitch sound that didn't alter, and so I left it there. The audio amp did sound to be working however.

Anyway, I'll keep this thread updated with progress.

Thanks very much to everyone for the help so far.

All the best.

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Topic starter Posted : 16/01/2020 11:24 pm
PYE625 liked
Nuvistor
(@nuvistor)
Famed V-Ratter Registered

In a Fringe areas noise in the video signal can cause inconsistent triggering of the line time base with direct sync systems. Flywheel sync attempts to smooth the triggering out to stop ragged verticals. 

F7C616D2 AC7C 4588 97A5 B532C5FA54FB

Spreadbury will give a full explanation.

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Posted : 17/01/2020 12:41 am
Nuvistor
(@nuvistor)
Famed V-Ratter Registered

There is a Spreadbury book for less than £10 incl p%p from a UK supplier, though no edition number given.

https://www.amazon.co.uk/gp/offer-listing/B01LQTQUJI/ref=tmm_hrd_used_olp_0?ie=UTF8&condition=used&qid=1579267326&sr=1-17

 

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Posted : 17/01/2020 2:25 pm
freya
(@freya)
Noble V-Ratter Registered

I have the genuine Ekco service data for this model, I can email to Chris to put in the library or if you PM me I can email them.

 

Stephen

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Posted : 17/01/2020 3:11 pm
crustytv
(@crustytv)
Vrat Founder Admin

Hi Stephen, all members have access to the File upload service (see here) if they wish to donate public domain material. If you would like to upload the EKCO sheet then please feel free to do so. It's not a direct load to the actual data library but into a temporary quarantine area. Generally once items are donated they're checked for virus, their copyright status, that they're not owned by another site, and are of readable quality. Then and only then are they transferred into the data library or in the case of a video, uploaded to the Vrat YouTube channel.? 

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Posted : 17/01/2020 4:52 pm
helloekco
(@helloekco)
Trusted V-Ratter Registered

@freya That would be great, thanks.

Is the Television Explained book co-authored by Spreadbury also worth getting, or does it cover the same ground as the servicing books, from anyone's experience?

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Topic starter Posted : 18/01/2020 4:01 pm
crustytv
(@crustytv)
Vrat Founder Admin
Posted by: @helloekco

Is the Television Explained book co-authored by Spreadbury also worth getting

Short answer, yes.

Posted by: @helloekco

does it cover the same ground as the servicing books, from anyone's experience?

The Spreadbury books (vol.1/2) are a totally different beast to the "Radio & Television Servicing".

Often referred to as the "Red books", these are a suite of books for a given year, covering TV and Radio circuits for various sets from post-war right up until modern sets, though I believe they became latterly known as U-view books.

Each of the red books has a small preface detailing the significant industry developments for that year/s. The red book circuit data mostly uses different component designations from "Trader", "ERT" or Manufacturers data, which is why its often necessary when posting about a repair to state what source you are repairing from, this allows others following to assist and avoid confusion. Personally I prefer manufacturers data first followed by Trader sheet, then ERT sheet and finally R&TS book. Sometimes though all you have is the book and any data is better than no data.

Note; with regard to the red books, there are many 10s to collect and are relatively easy to find from multiple sources, especially as you're a BVWS member, they crop up at their events frequently.

books
tvs 4

Radio & Television Servicing Books, Spreadbury Vol1 & Vol2, U-view TV and Video books

You will find most of us have both Spreadbury and a complete run of the 'Red' books to hand and of course many others.  Though I no longer do 405 TV repairs I would not part with my copy of Spreadbury as like Cathovisor states, its an easy read and probably the best book to assist in understanding the 405 line receiver.

So in conclusion, if you're serious about gaining an in-depth knowledge of how the circuits of a 405 television receiver function, then as I stated in post #2 get Spreadbury. If all you want is specific TV or radio model circuit data to enable you to repair a set, then just go for the red books.

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Posted : 18/01/2020 4:08 pm
helloekco
(@helloekco)
Trusted V-Ratter Registered

Thanks - and that's an impressive tech library!

Apologies for the confusion, what I meant was is "Television Explained" worth getting besides "Television Receiver Servicing" (both Spreadbury books).

I am keen to understand the general principles of TV; it's my fascination with this after all that led to my buying the Ekco sets.

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Topic starter Posted : 18/01/2020 5:05 pm
crustytv
(@crustytv)
Vrat Founder Admin
Posted by: @helloekco

that's an impressive tech library

That's just the tip of the berg, I have so much I'm running out of space to store it all. As and when its requested I scan and load into the website's data library which currently holds about 9000 items at last count!! I can for the most part unless its rare or exotic, provide members with most of their data requirements.

dat1
dat2
dat3
servd
dat4
Posted by: @helloekco

Apologies for the confusion, what I meant was is "Television Explained" worth getting besides "Television Receiver Servicing" (both Spreadbury books).

Ah-ha I see, in that case it's entirely your choice, I've not read the other book but if its as good as his other one then why not treat yourself ?

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Posted : 18/01/2020 5:38 pm
helloekco
(@helloekco)
Trusted V-Ratter Registered

@crustytv I had to smile at the similarities between those pics and my own "study"! I see you're into music (guitar?) too.

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Topic starter Posted : 18/01/2020 5:44 pm
Cathovisor
(@cathovisor)
Illustrious V-Ratter Registered

I'd say "get both books".

Although my profession was at the other end of the television chain, even in the early 80s we were still taught some  valve theory and practical fault finding on valve equipment as some pockets of it still existed in the BBC back then (the MN6/501 television waveform monitor comes to mind, and a few AM8/4 audio power amplifiers ). However, some of the more interesting and esoteric stuff regarding television receiver circuitry I was unsure about and having picked up one of the two Spreadbury servicing books at a BVWS meeting, I found it an enjoyable read on the train to work and then searched out  the other volume. This helped me understand what's going on in a typical post-war valve TV set much more clearly.

One other concise little volume worth having is the Television Engineer's Pocket Book, originally edited by Pat Hawker - this ran to several editions into the 1990s I believe. The best version to get in your instance is probably the third edition, dating from 1960. I have all the editions of this useful book - including Pat Hawker's personal copy, no less....  ? AbeBooks has examples of this book at under a fiver, including postage.

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Posted : 18/01/2020 7:47 pm
Nuvistor
(@nuvistor)
Famed V-Ratter Registered

If you want to check out the contents of Television Engineers Pocket book you can download it from Archive.org, let you see what it’s like.

https://archive.org/details/TelevisionEngineersPocketBook

 

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Posted : 18/01/2020 10:22 pm
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helloekco
(@helloekco)
Trusted V-Ratter Registered

@cathovisor Then I'll get both! Thanks for the recommendation.

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Topic starter Posted : 19/01/2020 12:46 am
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