Ekco TC267/1

[acottrell]

I don't have a 24V bench supply sadly. Good idea with the caps will take your advice!
Ade

[Philips210]

Originally Posted by Freya

Its a good idea to pass some current through the overwind on the lopt, this drives out any moisture and you get the full EHT, to do this you need a 1 amp bench power supply with about 24 volts. Leave it connected for 12 hours ideally. (it gets hot but not enough to melt the wax off)

Hi.

That's a very good tip and wonder whether it could be used on other LOPTx EHT overwinds to prevent insulation breakdown due to internal moisture buildup.

I was thinking of some of the more fragile transformers as used in a number of Philips monochrome TVs. Could colour TV overwinds be treated in a similar fashion? I assume it's a case of setting the power supply's current limiter for 1A to prevent overheating of the overwind.
I also wonder whether this technique could be used on the primary windings as well.

I've often placed the LOPTx on the workshop night storage heater and left it there for a week or two but the current through the overwind seems a good idea.

Regards
Symon

[Heatercathodeshort]

Don't forget the 'EGEN' capacitors that look exactly like resistors with the same colour codes. They go O/C and leaky. They have rounded ends, that is the only giveaway. You will have to replace the oil filled TCC silver ones wrapped in plastic around the frame stage to obtain 100% linearity easily obtained with this chassis. The LOPT looks good. Poor frame sync can be traced to the interlace diode Q3/4. It also looks like a fat resistor! John.

[dazzlevision]

Hello,

Take a look at this thread:https://www.vintage-radio.net/forum/...ad.php?t=98964

Post #1, picture 4 (far right), bottom two components.

I believe these were made by Dubilier, rather than Egen.

Regards,

Dazzlevision

[SteveCG]

Ade,

Thanks for taking the trouble to take the pics of the voltage setting panel.

There has been a discussion on another thread on this site concerning the different mains voltages (and also whether they were AC or DC) in the UK in the 1950s, and comment was made of the different selections that had to be made for some TV sets. Your pics show the complexity perfectly!

[acottrell]

Pleasure Steve
Well one lesson I have learned is get a circuit diagram before starting to replace capacitors!!
I am going to change all the brown caps first and then trace the values of the caps that look like resistors. I have spotted a couple of very fat resistor looking capacitors (or Diodes) Really glad I asked you guys for advise as might have caused all kinds of man made faults!
Will keep you all posted once I get chance to work on it again.
One quick question in the line output stage area is a .005uf brown cap will I get away with fitting .001uf instead? If not I I can make the value up with connecting caps in parallel but would look a little messy underneath. I have all the other values
Thanks
Ade.

[Freya]

Originally Posted by acottrell

One quick question in the line output stage area is a .005uf brown cap will I get away with fitting .001uf instead? If not I I can make the value up with connecting caps in parallel but would look a little messy underneath. I have all the other values

Is it connected to the 30P4 screen, a 4.7k and ground ?

either way it should be a 0.0047uF if you have a 0.005uF fitted now, might be best to avoid extra capacitors to make up the value in the line stage.

[acottrell]

Yes it is that's the one

[Freya]

genuine diagram shows it as 0.003uF, so anything between 0.0022 and 0.0047 should be ok if yours has the 0.004 fitted.

I have found the Egen type resistors on this series tended to be used only for the audio decoupling of the feed signal before the audio output valve, and a few others that are Pf values which tend to be fine....touch wood.(500 Pf value Egen connected to interlace diode usually)
The interlace diode has a semi clear body with an orange and yellow stripe, if the frame wont lock and keeps rolling then change it for a 1n4007

[acottrell]

Thanks mate
It is a .005 fitted so I think I will order myself the right cap .0047
Thanks
Ade

[Freya]

Hows the progress on screen ?

[acottrell]

Will wait for the caps I have ordered now so will probably be next week before I get chance to continue with her
Will keep you posted

[acottrell]

Hi Guys
Not had much time but replaced most of the hunts and wax capacitors in the line frame stages. Not yet touched the IF stages etc.
Please see the pictures below when I first switched it on.
First thing it came on with the picture shifted to the right of the screen. I made the mistake of trying to adjust the leaver on the scan coils however it suddenly lost half the picture on the right and was curved!! Moving the lever left to right several times I was really lucky it seemed to correct itself so not touching it again!!
The frame and line holds are stable locked in the middle ok. The picture does seem to (breath?) height slowly moves up and down and a slight ripple side to side so think I need to recap the HT cap?
Anyway looking good and will start carefully recapping the IF side (brown hunts caps)

[Freya]

That's looking great so far, can you adjust the linearity to correct the circle. If not the it would suggest you may have missed a capacitor in the frame stage.

[acottrell]

Yes I did manage to adjust the frame Lin no problem to give a good circle. Thinking of changing the electrolytic caps as well to give good service hopefully. Picture still not central more to the left but think I will have to live with that as I don't want to mess with the scan coils anymore.
Might not have too much time before Xmas now.
Really pleased with the set so far
Thanks for your help again
Ade

[Heatercathodeshort]

The picture shift lever is nothing to be worried about. It will move up and down and also from side to side to centralize the picture. It may be slightly stiff to pull up but you will do no harm and can easily be corrected.
Great receivers these Ekco models, in fact all genuine Southend-on Sea models. Very stable and will perform for hours without the slightest need for readjustment.
Your tube looks 100%. John.

[acottrell]

Yes the tube actually looks as good as new! The picture is very sharp. Might take a while but when I have finished it will post some pics

[acottrell]

Hi Guys
Just wondered if I can have more advised. Changed most of the capacitors in the time base stage. Tried some electrolytic caps but put the originals back again so not to create any more issues.
Still have the original fault the frame almost like a breathing effect. Its like a faint line going down the screen and the height goes up and down with it?
Also after changing the wax caps/Hunts caps I had no frame lock at all. Thought it was my fault but was so careful connecting up each cap. Turned out to be as you advised earlier an open circuit diode. Replacement it now locks again as before.
I have decided to run the set for a few hours before anymore work to see how stable it is.
After an hour and all the time now the line hold and frame hold although being dead centre to lock are both quite weak and temperamental? They are not very stable at all. Any advise would be appreciated .
Last of all I have not done much work to the IF stages etc but again after about 30 mins the picture looks very negative? backing off the brightness or contrast corrects this but you keep having to adjust it every few minutes.
Please see pics below of the negative picture ( the thick black lines have been picked up by the camera and aren't there on the actual picture). The under chassis shows the caps changed so far.
Thanks
Ade

[Freya]

Hi Ade,

have you changed the caps in the tuner yet ? this will most likely be the source of your picture negative. 0.1 on the AGC and a 2uF electrolytic on the tuner HT line.

[acottrell]

Thanks for that. I have changed the 0.1 wax against the tuner rear but not the 2uf cap will look for this one wanted to try and sort out the time bases first hopefully. I believe it would be in the sync separator stage I need to look for both line and frame?
Many thanks
Ade