Television 1960s 23" Weltblick 511TR
 

I just picked up this set as you can see from the pictures its in mint condition,very low hour,I only went for its cause of its nice wood finish,but when I got to it,I saw in what great condition it actually was.The
seller told me it was pretty much put out use as new,maybe cause the flyback failed on it and they never fixed it.It comes from Austria which means its a European set .When I went there to get it
the guy even had the original box in which this TV was bought new .

When I got it there was no raster only sound,so after further investigation I found out that the flybacks secondary winding had a short winding.

After rewiring and re-wounding it the set came alive but I wasn't ab-lee to adjust contrast and brightness,but the picture tube is very bright and seems healthy,which would make sense if its very low hour ...

After further testing I found a open winding on the secondary winding of the flyback,but more deeper inside then the shorted one ,open winding doesn't show on scope ring test,if it were a short then I would find it earlier .... The open winding is used in the voltage supply circuitry that goes to the grids of the picture tube (which could explain the brightness and contrast problem ...

So I had to rewound the flybacks secondary windings AGAIN (the non high voltage ones ) :sigh:
Now we will see if the problem goes away ...


Also what is the most simple way to inject signal/video in this thing ? I tried a vcr but didn't get anything ?? gonna try a different VCR later ...

Beautiful set with that nice wood. I also like the way the European sets have the CRT glass bulging out the front a bit and minimal or no mask around the CRT face. Now that you've rewound two different windings on the flyback, is it closer to working properly?

Well after rewinding it (also used better quality wire,with better insulation) and removing the short I got the results(see pic) but I wasn't ab-lee to adjust the contrast or brightness or very limited,the sound tuners worked okay

But then later I found a open winding that supply a voltage to one of the grids of the crt,so I had to rewound it all again (PAIN IN THE ASS) still in progress .

The pics tell more ... there you can also the the flyback before and after the re-wounding ...

For your signal input problem, give us some more info:
Is the VCR a European one? Are you trying to use RF or baseband composite?

I'm impressed that you were able to rewind the flyback.

I believe that there is a forum section specifically for non-North American region sets that this thread better belongs in.

Okay some update ...

After I fixed the open winding by redoing everything again the problem went away and now I can adjust brightness and contrast no problem,but I still think that like 25 % of high voltage is missing ,cause I get a dim spot in the middle of screen when I turn the brightness up and it even goes out of focus a bit in the middle ...

Also I replaced a very burn resistor that got hot,but checked OK on multimeter,is it possible if a resister gets hot it jumps of the correct value ??,cause when I replaced it
the picture got slightly better ??


I also used a smaller cap for the boost capacitor a 47000 pf INSTEAD of a 56000 pf
can that cause it to have low high voltage ? almost like the voltage supplying the high voltage circuits is low ??

If that cap is part of a resonant circuit (not just a filter) it could affect things.

[Edit - I also am impressed you could rewind parts of the flyback.]

If that boost cap is on the damper tube, then it's value effects the horizontal width and HV....It was a common trick on American sets to add extra capacitance by putting another capacitor in parallel to increase width when the H sweep tubes were running low on usable life.

Okay I did some searching

I think I have A CONDITION CALLED blooming which causes the raster to expand by 10 % if I turn the brightness up,loses focus in middle to,which it does and is caused by poorly regulated EHT ??

Also when I clunk thru the channels the dim spot goes away and the tube is flashing very bright so I know its a good tube,which means either poorly regulated EHT,B+ maybe...someone mentioned to me that
the B+ that goes to vertical deflection,that the fault might be there ??

Which means if poor regulated EHT ,would cause the tube to not operate at its fullest and I could have a much brighter tube if the things driving it would work properly :d


I just tried it with a 68.000 pf cap which is more then enough in the place of the 56.000 pf but results are pretty much same ...

How did you know how many turns of wire for each winding? I suppose one way is to keep count as you undo the old windings.

Coils usually used a criss cross winding pattern, the wires taking a pattern of \ and / as they go round the circumference of the winding. https://www.surplussales.com/Images/.../ich-9033a.jpg Hard to do by hand. This pattern is to reduce winding to winding capacitance.

You're lucky that the very high voltage winding wasn't atop the other windings.

Most monochrome sets lacked any HV regulation circuitry, And 'HV regulation' (more like HV sag) were usually caused by excessive load on the HV circuit, or the horizontal deflection system being miss-adjusted or having defective parts.

Yea I made a machine that helped me to unwound it and at same time count the turns and length of wire.., very handy


Ive used some kind of special tape for insulation between layers that I got from a guy who re-wounds motors and the flyback seems to be working GOOD ,no shorts/overheating/smoking so the hard part seems to be over

You can see from pics I stripped it completely down ...
But this dim spot and blooming,poorly regulated EHT is bothering me quite HARD


well maybe just a little but IF I turn the brightness close to max the dim spot gets even more visible and the focus goes away(raster stretches for about 10%),gonna take some voltages tomorrow and put a signal into it
and then well see where we are ...

Have you substituted the HV (EHT) rectifier tube? It is the most frequent cause of blooming.

Even if it tests 'good' on a tester, it can still fail in operation. The only valid test is subbing with a known good tube.

Well at this moment I don't have a spare one but the DY87 in the set seems to be OK ALMOST LOOKS LIKE NEW ...


it probably has bad EHT regulation,what components can I check ???
Also where can I found some lecture on how these things work,so I would know a bit more what I'm doing ??

A tube can LOOK PERFECT and BE COMPLETELY DEAD....However if it looks dead (white getter, hole or crack in the glass, etc) it is dead. The only sure test of an HV rectifier is to get another HV rectifier and try it in the set. No tube tester made comes close to testing HV rectifiers under real world application conditions.

Also there is almost certainly NO HV regulation circuit in that set. Usually they design the horizontal deflection system, flyback, and HV rectifier system to produce varying, but acceptably varying HV output. However if the HV/horizontal deflection system is loaded beyond design (as I suspect yours is on the edge of, since increasing the brightness pushes it over the edge), or the oscillator/output is not preforming correctly it will vary outside the acceptable range.

There have not been lectures on this subject in decades. You can find some TV troubleshooting videos on youtube (Banderson has many good videos) which may be helpful, but you are best off getting some TV servicing books off the internet, and reading them. Also google searching this forrum and others like it will dig up some good info on horizontal troubleshooting. Unless you can find someone with the same set and issue the info will be general, and possibly not completely apply to your set.

Okay gonna try a different DY87 ...

Also a new problem has developed,I only have a raster now,the snow disappeared,but I know the tuners work cause I have perfect sound only
picture went away ,only white raster ,when I measured the voltage on the cathode of the CRT was only 14 V which is a bit low and pin 6 had 12 v instead of 80v and pin 9 had 260V instead of 210V

there is something weird going on in this TV ...

Okay I did some further testing with it and hooked it up to the analog cable

I got perfect sound,works great only problem is picture is very weak,likes to shift up and down and there are multiple picture in the screen,when i disconnect the signal the snow comes up and is sop much brighter then the picture ...

Also the pcl84 SEEMS A BIT TOO hot,seems there are problems with the video amplifiers as well ,tuners seems to be working cause I have great sound .

were to investigate now ?? I have a scope,can that HELP ??

Have you tried adjusting the horizontal and vertical hold controls to try and get it to synch? If not, then do it.

Does your set have an 'AGC' control as we call it here in the USA? If it does try adjusting it. Miss-adjusted AGC can cause loss of synch, and poor contrast like your pictures show.

The picture is basically cut and the two parts of the picture are switched,the bottom is on the top and top part is on the bottom as you can see more in pictures ...

Definitely has a problem with the video amplifiers and circuitry,focus and geometry is out of question at this moment !

It could either be the EHT,video amp or CRT voltages,on a grid there should be like 400V and was like 173V (measured with a multimeter)

NOW it does lock horizontally and vertically OK but the picture is still messed up not to mention the lack of contrast/brightness ...

It doesn't have a AGC,I tried every adjustment on the set except for the if coils and pic related is the best I can come up with right now ...

HELP ...

It would appear that your sets vertical deflection circuit is operating at twice the proper frequency....It can obviously still synch but it is scanning the top half of the frame over the bottom half. I had this exact issue before once. What you need to do is replace all capacitors in the vertical circuit, and test all the resistors in the vertical to make sure all are within rated tolerance (if any are not in tolerance replace them obviously)....If that does not fix the issue, then get a resistance decade box and start trying different values in place resistors in that are in that circuit (which is what I had to resort to).

As for the brightness make sure the HV is correct, and the cathode grid and screen voltages are right. If any are wrong track down the problem in the circuits supplying it.

Well I don't have a HV probe,there is no other way to test it right ?

To me all the caps look OK,all the paper ones were already replaced,there is a bunch
of polyester ones but they normally they don't go bad and I didn't even find one resistor off value only one that was open ...

There is another think I used a bit thicker wire to rewind the flyback secondary winding(0.30mm instead of 0.22mm wire) can that cause the EHT to be lower ??

I had a similar problem with a zenith. Try different IF tubes.

There seems to be something seriously wrong with the line oscillation on this thing

Okay so now the PL504 sweep tube gently and slowly starts to red-plate (also it sounds like it clicks inside the tube)after 30 seconds of set turning on,which means the cathode current start to go a bit high,which could be caused by the oscillator running at a too high frequency ...(on pin 6 there is 160V and it should be 215V but I checked all resistor and they all fine)....

Now I suspect the two yellow diodes in the pic cause they are connected to the grid of the PCF801 and when I try-ed testing them,I got nothing on the meter,like they would be open,or was I doing something wrong ...


Also does the tube in pic look shot,its a mini-watt PCH200 AND IS CONNECTED DIRECTLY on the two yellow diodes ...IF you look the getter it has some sort of white stuff there,can that be a indication of a gassy/bad tube ??

PROBLEMS:

-cant get a clean picture,its cut and the two parts are switched around ,which could mean the oscillator is running too fast and if I try adjusting it there appear multiple pictures and the bleed into each other ...

-PL504 gently start redplate everything else from the EHT prospective seems to run fine,except for the blooming problem(could be the DY87,BUT THAT CANT AFFECT THE PICTURE PROBLEM)

-OSCILLATOR isn't running correctly and the high pitch is so loud that my ears hurt,which is another indication that it seems to run too high ...


I USED THICKER WIRE WHEN I WAS REWOUNDING THE FLYBACK SECONDARY WINDING,WHICH THE OSCILLATION FROM THE TUBES GOES THRU THESE WINDINGS ,CAN
THAT BE THE PROBLEM OF THE?,CAUSE OF THE CHANGE IN RESISTANCE AND STUFF ?? (0.30MM INSTEAD OF 0.22MM)




it has a solid state IF

Milk white getter means the tube has lost it's vacuum. What I see would indicate that the tube is either beginning to take on gas, or has been ran long and or hard enough to wear out the getther. I'd get a replacement for that tube or at least test it.

HO Tube redplating will quickly kill the HO tube. The horizontal appeared to be on frequency in the pictures you posted. If it is like the American Synchroguide horizontal oscillator circuit then it can be on frequency and still miss-adjusted....There is a certain waveform in the oscillator that is supposed to be tweaked such that the point is at the same height as the hump on the other side of the valley between them when viewed on an oscilloscope.

Has the horizontal section been recapped recently with good parts? What are the cathode, grid and screen voltages on the H output tube, and what does the service literature on it say it should be?

I'm no expert on rewinding, but I'll say this: They chose the thickness and turns ratio of the windings for a reason and changing that without understanding of the design process, unless you absolutely could not obtain the same type of wire, is a risky move. On things like that it is best do it right the first time.

Okay so I probed it with my scope and here are the results,was scoping with the disconnected (G2) feed resistor to the PL504 and I heard the oscillator just a bit,not as loud as If I connected the g2 feed resistor back ...

I also measured the PL504 cathode current at first when it starts up the current is between 190-210 mA then it goes to 220-250 mA and isn't still,it jumps a bit down and up and down,when it reaches nearly 260 mA then red plating starts ...The horizontal frequency coil has a affect on the current but the current just keeps jumping around,the EHT ,both deflection seem to be stable and working fine ...

Voltages : some of them are off ... The g2 feed resistor to PL504 connected !

PL504

1. -37V
2. -36V
5. 54mV
6. 160V
7. 160V
8. 0.2V
9. 17mV

PCF802

1. 213V
2. -0.8V
3. 97V
6. 150V
7. 11.22V
8. 13V
9. 8.5V

PCL805

1. 300V
2. 230V
3. 250V
6. 258V
7. 250V
8. 32V
9. 11.6V

What would cause the cathode current to jump around like that and not be stable ?
The 500K potentiometer in pic was burnt a bit ,but when I tested it tested GOOD ..
Then I replaced the VDR resistor and it seems to be fine now ...

This TV is beginning to be a real pain in the ass ...

Okay so I finally got a decent picture on it, after re-rewounding the flyback with correct thick wire and replacing the High Voltage winding as seen in pictures.The new HV winding measures about 130 ohm, if that maybe tells how much kV it produces, it should be 18kV, but I have a felling its a bit higher then that.

but now that I replaced the HV winding I'm thinking the high voltage might be a bit excessive which can cause x-ray radiation, is that possible ?

I used the winding from a flyback out of a 80s color TV which used a tripler.I need to get a high voltage probe to be sure, but it definitely is a bit high because brightness is very limited.Is there a way to lower the HIGH VOLTAGE somehow without to much complications ??

there is also a problem with bars appearing when there is a bright white dot or face(look at picture 3) what could be causing that ?

but overall not to shabby !

IIRC X-rays form around 25KV, and tend to be fairly weak....Unless you stand closer than ~2 feet from it for a looong time you probably are not getting hit with a dangerous or even measurable amount X-rays.

The bars are likely a symptom of the set's designers not adding DC restoration to the video chain....There are period articles on how to add DC restoration you may want to look for.

It looks like your set has got case of the cone heads... The height and vert lin controls could probably use a touch up.

On the HV there are a few solutions. A roughly 3KV IIRC pF rated cap (or change in the cap's value) across the damper tube will change width and HV, reduction of HV winding turns will reduce HV, a resistive voltage divider may be possible with HV rated resistors, it may be possible to load it down with resistors or something like a 6BK4 HV regulator tube, but that could strain the flyback if it draws too much power.
GET an HV PROBE before trying any of this! You need to know how close you are to spec before tweaking! If the HV is within 4KV of spec you are probably best off leaving well enough alone.