After 20 years I finally got around to tidying up this neat little telly.
Pots, selenium bridge, EHT capacitor and a strip-down, wash and re-cover the case wrap.
I'll just put up a few pics for now,
If you are interested in the whole story (including how to make a new EHT filter cap and replace those front panel pots), let me know!
Looks great, with a decent tube and good cosmetics. I'd be interested in the whole story!
Well done.
Pete
It looks really good. Ekco sets around the late 1950’s early 1960’s were excellent performers and usually straightforward to repair. Of course that was in the design service life, after 60 years anything can fail.
I will certainly read the whole story.
Frank
Looks very good, I’m presuming this is a 625 version?
John.
Yes the TX275 is the CCIR 625 line 5.5MHz FM sound export version. With a 12 volt DC vibrator power supply.
I bought it on Fleabay 20 years ago and fixed the vertical fault that someone else had been trying to fix, replacing almost everything in the vertical. The LOPT was replaced in the early 60s along with some of the paper caps. Somewhere along the way the 6S2 EHT rectifier was replaced with a selenium plig-in service replacement.
I pulled it out of the garage last year. It worked, but the picture was dim and increasing the brightness pulled the width in. So it sat on the floor in my workshop back room with the cover off, taunting me to get around to finally fixing it properly and cleaning it up from 70 years of grime.
With the HT sitting on 140 volts, it was time to replace the selenium rectifiers. And that paper cap across the HT secondary.
While I had it apart I replaced the three very scratchy hold and contrast pots with Alpha pots, I cut the knobs off the original pots, drilled them out and glued them to the pot shafts with construction glue.
Also dismantled and freed up the FT shaft that was bonded to the channel shaft with grease that gad turned to glue. Those circlips always seem to want to escape, don't they? (no pics of this)
I also cut down the concentric volume - brightness - switch pot which looked like it had been replaced in the 60's with a longer shafted assembly. This made the knobs stick out in an ugly fashion. Now fixed.
Well, with 4 x 1N4937s installed, B+ was now 200 volts. The little set really sat up and took notice, delivering a much brighter picture and better performance all round.
But not for long. The .001uF 20KV Visconol on the EHT slowly started breaking down. I considered re-stuffing it but rejected that idea because it's old enough to contain poly-chlorinated-biphenyls - nasty carcinogenic stuff. Better it stays sealed up inside!
I made the replacement cap out of PVC conduit parts and filled it with hot-melt glue.
I also replaced the selenium EHT rectifier with a HV silicon diode, potted in a syringe barrel with hot-melt.
With the little telly now working well, the front and back panels scrubbed up in the kitchen sink and re-assembled, it was time to turn my attention to the cover. I'll do that in a following post lest this one gets too long.
OK, time for the cover.
After washing it, upon drying the dark green (vinyl?) fabric that covered the aluminium wrap had white streaks through it. I tried neutral leather polish, while this got rid of the streaks the results weren't good. Still too many dings and scratches!
Without much hope I visited our local Spotlight store. Et Voila! The right colour fabric AND the glue with which to apply it!
A soak for a week in a tub of water and washing detergent freed up the original covering, allowing it to be removed. A further soak did the same for the remaining glue.
Some paint stripper got the old paint off the grilles, not without some effort and burnt finger tips!
The deepest green I could find in a rattle can for the side grilles turned out to not quite match the can cap when sprayed. But the finish is good so I guess I'll have to live with that!
Not much to say about the recovering process. I couldn't take pics, my fingers were covered in glue!
Oh BTW, White vinegar is excellent at cleaning up rusty parts.
Anyone got a datasheet for the CRT in this set, a Mazda CRM93?
I have the datasheet for the CRM92 on which this tube seems to be based but this one is aluminised.
And yes, it's original.
Not that it needs replacing, just curious!
As requested
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Crusty's TV/VCR Collection: View my collection
Thanks!
I wonder is that price still good? lol
Looks like the gun is the same as the one in the first EKCOs made here in 1956, 17" 70 degree tetrode mag focus with ion trap.
The fibreboard cover on the base of my TX275 (underside of the chassis) has a bad woof in it.
Anyone know how the flatten it without damaging it?
Also, you guys know what parts can be trusted in UK sets and what can't.
The little telly is running perfectly, it's had partial recaps at different times in its life.
But can you see anything under there that should be replaced?
I've heard "anything with HUNTS on it"!
You have made a superb job of that! I had one of these as a kid it worked but not well. I passed it on to a friend at school who destroyed it fairly soon afterwards!
As it is working well nothing can be too wrong, if you have any leaky capacitors they must be in a circuit that is tolerant. Those brown moulded capacitors with the orange labels are similar to the dreaded Hunts and are probably leaky and way off value but if it works...
There are a few various opinions on restoration. Some collectors like to change almost everything to get the best performance often modifying circuits along the way, Others just change what is necessary to get it working and deal with any faults as they occur. Others leave all as is and accept that it is a non working display piece.
I have a fully working TV22 rebuilt with what I had to hand. no "resuffing". Another TV22 is completely original full of waxies left completely original.
Rich.
As requested
And here to emphasise a point often made, the figure for the beam current (150µA) shows clearly why a B&K 467 is utterly useless for testing older mono CRTs - the metering on a B&K being designed to measure beam currents of up to 2mA.
If you want to test old tubes, buy yourself a tester contemporary to them such as a Radar or a Beamec/Grunther.
Also, you guys know what parts can be trusted in UK sets and what can't.
The little telly is running perfectly, it's had partial recaps at different times in its life.
But can you see anything under there that should be replaced?
I've heard "anything with HUNTS on it"!
Even in professional circles the phrase "Hunts crap - hook the rat out!" was to be heard.
Your set doesn’t appear to have them but there are capacitors which at first glance look like 1K resistors. They are or were 1000pF and were usually employed as screen grid decouplers in the IF amps often causing complete loss of vision or sound. They may have been manufactured by Erie.
John.
Very nice set. I didn't know they made a 625 line version so nice to see. This is my TMB272 which I did over 15 years ago. 405 line of course. It did get a fault where the vertical lock became very week. Textbook fault as the field sync integration capacitor had gone open circuit C121.
@hurty I'm sure I read somewhere that there were 625-line versions of the TV22!
