Telefunken Palcolor 818 22"

[ben]

This set dates from the mid-late 70s. I got it years ago, saved from a skip, and just got round to attempting a repair! (pics to come, camera on charge.).

On powerup, there is sound and tube heaters, but absolutely no EHT action (and consequently, no raster). A quick visual inspection showed the LOPTX is not in great shape; there is a small crack in the ferrite and the plastic strut on top of it is cracked, maybe from when the unit was dumped. The line o/p transistor checked OK out of cct.
I need to find out what chassis this is so I can get a schematic and start tracing things. It is not dissimilar to the 711 set I also own. Any thoughts ?

[ben]

some photos. I should add that this is a Spanish manufacture.In fact the plant I believe was here in Madrid, 5 minutes down the road from me! Now there is a circus on the site, before that a pharmaceutical company had the premises until demolition in 2003.

The last two pics show the damage to the LOPTX, you can even move the coil with a finger so I will try and source a spare.

[ben]

A few more including front of set. Sadly it got a ding on the speaker grille in storage, fortunately I have the missing pieces ready to reglue.

[Heatercathodeshort]

You may have to strip the LOPT down to the core and superglue it. Clamp it tightly and leave for 24 hours. If it mates 100% it should be fine. Worth checking the continuity of the windings before you go to all that trouble. John.

[Nickthedentist]

Nice find, Ben.

Surprising to see only 4 channel positions on such a posh-looking set, and that the fourth one is labelled AV. It would have been "IBA2" over here, no doubt.

Nick.

[ben]

Some progress. Got the lamp out and inspected the line panel from top to to bottom. R563 (22r) in the line drive stage was o/c, because c566 (22uF) was s/c and fell apart when I removed it. Now have EHT and a full raster (surprising considering the state of the LOPTx!) .

There's still work to do. The tuner may be faulty, as on a tuned signal (from a STB), I could only get a three- quarters height picture in black and white, with some tearing.
Plus, the set tended to jump across the three presets - it's a touch tuner so may be a leaky diode - not really familiar with them. Will try with a different analogue source...meanwhile , still after a schematic!

[jayceebee]

What type of CRT is it? looks like 110 degree but is it inline or delta. Don't recognise those neck components.

[ben]

It's a miniwatt, will take a closer look later and get back to you

[mickash]

Check for any build up of grease or dirt on the touch tuner contacts. This can fool them into thinking that they're being touched.

This was a common problem with touch tune sets, especially when the weather was damp or the air in the house was humid.

If the channel indicators are neon lamps then a faulty one can also cause channel tripping.

Michael.

[Andy Doz]

I would err on the side of caution before attempting to glue the loptx. I had a G11 with a broken core that was fine before I superglued it. After that the line output transistor had a short life. I suppose I had "gapped" the transformer. A replacement transformer sorted it.

[jayceebee]

Originally Posted by ben

It's a miniwatt, will take a closer look later and get back to you

If it's a Miniwatt then I would suspect it to be an A56-140X or 410X delta as in picture one it appears to have a small convergence board tucked away on the extreme right hand side. Interesting find, good luck.

[ben]

It's an A56-500x, and there is a separate E-W correction pcb. The yoke has a 'made in Portugal' sticker on it. I think I have a Blaupunkt set of similar vintage with a tube like this, but they are far from common!

[ben]

Originally Posted by Andy Doz

I would err on the side of caution before attempting to glue the loptx. I had a G11 with a broken core that was fine before I superglued it. .

Noted, thanks. Will leave well enough alone for now.

[bobbyball]

Hello Ben, just to say the tube is a "20AX" type, first generation "thick neck in line" 110 degree. I'm sure you are familiar with them, used in the Philips G11 series for example. The correction magnet unit is unusual but I remember seeing this in one of the Radio & TV servicing volumes - a Telefunken set in fact - with adjustments like that.

Best Regards

Robert

[julie_m]

Originally Posted by Nickthedentist

Surprising to see only 4 channel positions on such a posh-looking set, and that the fourth one is labelled AV.

I don't think Spain was ever renowned for having a huge choice of TV stations .....

[ben]

I've not come across this few presets on a large set before either. I had the 26" version of this set years ago (sadly left it when I moved house) and it too has 4 presets.
Spain had only two (some areas 3) channels until 1990, when Antena3 and Tele5 both appeared.

[ben]

A happy ending!
Turned out the modulator in the STB I was using was duff, and trying the unit with a VCR gave a pretty decent picture. The tube is in fact remarkably good for 1978. There is some minor misconvergence which I will attend to at a later date. I found the loose parts of the wooden speaker grille and carefully glued them back, unless you look really closely you cannot see the repair (which I am happy about, as the rest of the cabinet is in pretty much perfect condition).

I cleaned the touch panel and there is now stability with no channel hopping! The VCR works well on all presets not just AV. A new double insulated mains lead and I'm ready to put the back on this 'un. More photos attached.

[hans]

Originally Posted by ben

It's an A56-500x, and there is a separate E-W correction pcb. The yoke has a 'made in Portugal' sticker on it. I think I have a Blaupunkt set of similar vintage with a tube like this, but they are far from common!

Is this tube of Telefunken manufacture? Back in the days I changed loads of TFK made tubes. This was the most common fault on these sets. Here we mostly had 26" sets. I can't remember seeing a 22" set with this tube. They had some thin neck tubes of this size. They didn't have Blaupunkts with these tubes and yokes here.

[Maarten]

Miniwatt was used by Philips as a trade name in Spain. It was probably manufactured by Philips in their Spanish CRT-plant. This could be confirmed by looking for white stamped ink markings on the bell of the tube. I seem to remember the site code would be ZM for a Spanish tube.

The yoke could be Philips as well, as they had a factory for wound components in Ovar Portugal, however it certainly looks like a Telefunken yoke. Are there any markings on it?

[GLENZ32]

Nothing wrong with that picture! Looks pretty good really. I'd leave that LOPT alone if its working as it is. Cheers Glen