Ekco T344

[Radio Tech]

Hi folks

Picked this Ekco T344 television set up today from Dave and no sooner had I placed it on the work bench off came the back. Those shrouds that not only house the windings on the LOPT but also provide support for the EHT rectifier and it's associated connections, now the question is where can I find a shroud that is in good condition and as you see from the condition of the original one it has seen better days. It was a pity that Ekco when they designed the set did not consider using a more robust material for this transformer, so has any member any Idea where I could find a shroud for this LOPT.

Best wishes

Ken

[Freya]

Not able to help with a replacement, but have a suggestion to make one up using fiberglass board and epoxy.
This is one I built for mine a few years back. To keep its shape whilst building it I used a block of wood the right size covered with Selotape to prevent any unwanted sticking to the block, the eyelets were re used from the original.

[MonochromeMarc]

You could try bending a piece of perspex in the fashion of this photo....

Marc.

[Radio Tech]

Hi Stephen,

Your design of making the shroud looks like the proper job, I will see if I can replicate your design. I assume that once the fly leads have been disconnected and the screws that hold the transformer removed, the whole transformer will come out with ease.

And thanks Marc for your input on this, but I would prefer to have something more like the original shape and design.

Will update on the progress, might be a long job this.

Best wishes

Ken

[Nuvistor]

The photo of the chassis brings back some memories. Those LOPTX housing failed quite early, if I remember correctly Ekco did change the material but I changed quite a few. The 30PL13 frame valve had a hard life, we used to put a small resistor in the triode cathode to lift it off chsssis and a 700-1k resistor plus a screen decoupling capacitor. This lengthened the life of the valve witout affecting the height or linearity. The other common fault was the 27k resistor from HT to the cathode of the video output valve, it went low in value, well burned.
Capable of an excellent picture but unfortunately I cannot help with the LOPTX.

Frank

[Radio Tech]

Hi Stephen,

Have you got the dimensions of your design of shroud for the LOPT, be helpful, I tried making a model of one with cardboard but looking at your pictures its difficult to judge size and measurements, one I made came out too big I think., and thank you Frank for the mods on the frame valve, get the size of shroud right first though before I venture any further. Pity someone hasn't a scrap lopt with a good shroud but never mind.

Ken

[Radio Tech]

Hi Folks

Here's an update on my progress with this set, after really having a good think, I managed to make up a shroud for the transformer, it was constructed out of stout card and the pieces glued together with super glue and masking tape, the tape used to give a little more strength. The top 80mm x 72mm, two sides 80mm x 28mm, valve supports 80mm x 15mm and the lugs 30mm wide a 12mm x 15mm section that latches into the body and 15mm section that is stuck to the sides. I used solder tags and nuts and bolts for the winding connections and to fix the shroud I used some solder tags screwed and crimped to the body.

This is what it looks like

Ken

[Hunts smoothing bomb]

It looks the part but I fear that this will be very short lived, the card and tape will inevitably draw in moisture and with those voltages and currents involved it will track and undoubtedly catch fire!

I would model one from fibreglass PCB material for longevity.

Cheers

[Restoration73]

You might get away with it if you cover it in polyurethane varnish.

[Freya]

You don't need my measurements now Ken
I purchased my fibreglass sheet from ebay.
In hindsight it may have been easier to score the sheet along the lines and actually fold /fracturing at the bends, then run a bead of epoxy to fix the shape.

[The Philpott]

We need a benevolent person with 3D printing technology and the knowledge to use it..

[Radio Tech]

Hi folks

yes have started to cover the shroud with something that will keep moisture away, but at the moment my main problem is getting the chassis out of the cabinet, I have released the screws that are mentioned in the service data but the chassis just will not budge, and the only way I can see of getting it to move is take the whole front off but saying that I have got to acquire a very long 4BA nut runner to reach the fixings at the front, keep you all posted,

Ken

[MonochromeMarc]

Hi Ken,

A few years ago I had the same problem removing the chassis from my T344, you will find that it's the rubber mask that has stuck solid to the CRT.
The way I freed mine was using a piece of straightened coat hanger wire and bent a short right angle at the end then fed the wire in from the back of the set and hooked the mask edge and pulled it away from the screen working slowly round the whole CRT. It was slow work but eventually the mask let go of the CRT and out came the chassis.
There are probably other ways of doing this job but this was the only way I could find that would do my set, and trust me it was stuck like super glue !

Marc.

[Radio Tech]

Hi Marc

I got the chassis out after have to take the front off, and yes the mask was stuck to the tube and freed it off, now the work begins, I found the metrosil had fallen apart but Dave who called today said it the set will work without this, the main smoothing cap a 200uf and a 100uf in one can had blown out and I have got all the waxies to replace as well. Not sure if I can get those values in the smoothing cap with such high ripple 750ma it says on the can. Well at least the glass in cabinet is clean now, still waiting for some fibreglass board to arrive so I can re do the shroud on LOPT.

Will update as progress

Ken

[Heatercathodeshort]

Ken, please don't go on a mad cap change. Start with the power supply, line timebase, frame timebase, IF and video/sync tuner and sound.
These are easy to get going and give one of the best pictures you will see on a 405 line receiver. If you work on this procedure you will see the faults unfold and you will gain a lot of knowledge wasted with a mass replacement of components. Good luck with it and take your time. Your lopt case will be fine to get it up and running. Good luck with it.
The Mazda CME1703 CRT if original will probably be woozy but usually respond to my old black Bertha. Regards, John.

[The Philpott]

Good progress. Hope the bit of ply delamination at top right hand (rear) corner of case, is glueable- The top wooden rib also looked to have come unglued from the case at this corner, but evostik wood glue claims to be stronger than wood

[Lloyd 1985]

I have an Ekco T368 which looks like the same chassis as your set, my LOPT case had rotted just like yours has! I built mine from some board that looked and smelt just like Paxolin, it might have actually been Paxolin... It works though! My metrosil is missing from mine, it works without it. I also had a burnup to repair on the PCB at the top, there was a resistor that had turned to ash, and the board was so conductive around it that it was measurable on my DMM resistance range. I had to cut a lump out in the end and rebuild damaged tracks with wire. There is a thread on the VRAT forum showing the full repair to that set, it gives a great picture now, even though the tube tested as a dud!

Best of luck with yours,
Lloyd.

[Tazman1966]

Hi Ken.

My T370 had the same issues with the LOPT housing. John (Heatercathodeshort) very expertly rebuilt mine as can be seen in this thread.

Good luck!

[Radio Tech]

Thanks John for that advice, I have now changed the smoothing cap and those associated with line time base as you suggest. I will of course take my time over this little set and as I work through it you are quite right, it will provide me with a great deal of useful knowledge. There is plenty to do on it yet so it will no doubt keep me occupied during the coming winter months. Keep all posted.

Best wishes

Ken

[Freya]

These are the measurements from the one I made, final dug the set out.
Hope it helps, sorry about my drawing.