Ekco T368F

... The dropper too is getting slightly agitated after a while ...

Sorry, Stephen, but I can't make sense of this! It's a stonking great wirewound resistor that runs at high power and chucks out a lot of heat but I've never heard of one getting 'agitated' before ...!

It's one of those components that either works or it doesn't! The major part of it is the 300mA heater section and that shouldn't be carrying any more or less than that provided that the heater chain is intact and the mains voltage setting is correct. Any short circuit decouplers anywhere on the heater chain should be able to signal their presence by extra bright heaters plus some not powered at all ...

A short on the HT end of things should have much better ways of making its presence known as well!

I'm a bit puzzled by the dropper tappings, though. Unless I'm very much mistaken, the HT and Heater tappings don't match ...

... also would anyone have a spare plastic locator for the tube neck ?

Do you mean the plastic 'handle' on the width/linearity shorted turn adjuster under the scan coils? If so, and unless you need to adjust it (which probably won't be necessary of it has never been disturbed) you can ignore it.

I can't think of anything else it might be ...

I can see a hinge pin by the dropper and there is likely to be one behind the tag strip.
I can also see a bracket at the bottom left that will have a screw.
There may be another at the top left that I can't see.

... I can also see a bracket at the bottom left that will have a screw ...

It looks to me like a wing nut securing that bracket, assuming we are both looking at the same one ...!

I'm sure I can see the end of another wing nut peeping out at the bottom right hand corner as well. Perhaps the chassis slides back when they are both release?

And what is that lever protruding from the top centre?

I think that the wing nuts are most likely to release the chassis and frame complete.
I would undo the screw/nut from the bracket above the left wing nut and waggle the chassis and see if it flexes where the top leaver is. If so then waggle the leaver until it moves to one side.
With luck it should then swing out.

Well, some progress to report already. Checking through what i can get to C91 which is between HT and chassis was almost short. Replacing this with a .22uf has given me first light.
Not bad, three capacitors including the mains filter !

The chassis does in no way pivot or open out sadly, the metalwork seems to be just for support.

Sorry Trevor i missed your post. Most of the muck has blown off.

Stephen

That's a very neat job, Jeffrey!

What did you use on the corners? Epoxy, possibly?

It wouldn't have looked quite so neat, perhaps, but I would have probably used a piece of right angle plastic section inside for reinforcement ...

I must admit that I've never seen sleeving on the lead outs of a U25 before, though ...! Very classy ...!

Where would i get some of that material Jeffery ? all i can find is copper clad stuff

Nice job though, fingers crossed i can produce something similar albeit smaller as the t368 only uses the top half effectively to hold the rectifier.

Stephen

Thanks, will have a look at required size in the morning.

Stephen

If you take a look at my T345 thread you will see that I encountered the same problems regarding chassis removal and LOPTX . I think the two sets are very similar, I think the spare chassis that I acquired was most likely a T368.
I had to use a scalpel blade to release the crt before the chassis would come out and yes you do need to remove the chassis from the crt to do anything useful really.

Ecko_T345_about1247.html

Eddie

This is the problem i was describing previously.

Would anyone have a spare from a duff tube ?,it crumbles to the slightest touch

Stephen

I've encountered this many times on tubes of this era. What I normally do is rebuild it with Araldate. I've done this on about 5 tubes thus far and some I have as spares. Works a treat and none have failed to repair. You will have more luck finding rocking horse poo than one which has not suffered.

Do you build up from scratch or glue the bits back together ? I doubt if i could get any result from gluing the bits together it reminds me of a sandcastle at the beach, looks ok but when you touch it it disintergrates.
Would you have a picture of your result chris ?

stephen

Not to hand I'm afraid. Luckily mine had broken in two or three bits and have gone back together quite well with a liberal coating of Araldite. If I had one in such poor condition as yours I would make one from wood.

Thanks Trevor,

I would never win a race with a true expert in their field, after six sets i dont come close

Stephen

Jeffrey,

I managed to find some grp sheet from a model supplier, looks fine for the job. Are the webs either side of the rectifier purely to keep the rectifier straight ?

There is a major difference in the layout of the RF section of this set, compared with the trader sheet things are in different positions. Takes slightly longer to identify some components value in particular some of the resistors that have got hot and lost colour bands.
Some of the resistors seem quite a long way off spec for example the 1 megs are reading 1.7 meg on average, the 270k ones read 420k average. Its difficult to decide if its worth changing them bearing in mind the trouble it is to gain access when the tube is in.

Stephen

Try this:

Using a vernier gauge or similar (if you haven't got one, I can recommend the electronic one Aldi have for £9 on Sunday: http://www.aldi.co.uk/uk/html/offers/sp ... 2-08-11-12 ) accurately measure the the inside diameter of the circle of contacts on the tube holder - i.e:. across the base to the inside edge of two diagonally opposite holes

Remove the remains of the spigot from the base and find a drill, rod or pipe that is a good fit in the hole in the tube holder to use as a former.

Grease the former lightly, then take a strip of sticky paper as wide as the length of the spigot and wind it round the former, sticky side out. It only needs to go round sufficiently to meet up with itself and glue itself into a tube. After that you can use plain paper and PVA or similar to continue the process. Use the vernier to check the outside diameter - stop when it reaches the figure you measured earlier, not before - cut the end the paper strip off and leave to dry.

When it has set hard, check it on the tube base to make sure it is a reasonably snug fit inside the circle of pins. If it is too tight, use sandpaper to reduce it until it fits. Then use a saw to cut a slot lengthways for the keyway then, with it on the greased former to keep the the size correct, stick a thin piece of paper or sellotape across the gap - not too much or it won't fit the tube!

Make sure it is well greased inside, including the keyway slot, and position it on the CRT with the keyway in the right position - you'll want the tube face down for this. Now fill the mould with epoxy and leave to set.

Finally, remove the mould and check the spigot for fit - you may need to dress the keyway slightly with a sharp craft knife or needle file if it is too wide. If the mould comes of intact, keep it in a safe place in case you need it again!
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EDIT Alternatively, take up Trevor's kind offer ....!

... Some of the resistors seem quite a long way off spec for example the 1 megs are reading 1.7 meg on average, the 270k ones read 420k average. Its difficult to decide if its worth changing them bearing in mind the trouble it is to gain access when the tube is in.

As we discussed in another thread recently, low resistors go low and, as you have discovered, high values go high!

They ain't ever gonna come down again, Stephen!

I'd bite the bullet and change them ...

However, I recall one replacement shell that was marketed when these sets were in their heyday that consisted of a piece of perspex (presumably) shaped into an inverted 'U' ...

No wings, inside or out, and no problems with the EHT either ...