Powering up older restorations.

[Jan Zodiac]

Hi all,

After cleaning in my storage room, I decided to power up the tv's I have. At least the restored ones. I don't have a lot of them, but I was still a bit shocked when I realized that several of them had not been powered up in around 10 years or so. They just sat there since I finished working on them. At least with tv's, it is good practice to power them up every now and then.

First one is the Philips TDK1420U. This 14" model was produced in several countries. I think I have an unrestored belgium or dutch version with the multi standard option.
Anyway, this particular set was build here in Denmark, hence the "DK" in the type number. It is a 1953 split carrier set, and it is quite well build. Sound output has a push-pull stage with two ECL80's. Both picture and sound is great.

A tag inside says I bought the set in 2011, and restored it in 2013. I know for sure I never powered it up since. When I got it, it was in a relatively poor condition. Cosmetically it was okay, and some polishing made it look great again.
It was worse on the inside... Some sort of a "technician" had apparantly been "working" on it. First of all, the base of the CRT was crushed. At some point the set must have been hit pretty hard at the rear.
I carefully managed to glue most of the remaining pieces of the base back together, without damaging the leads coming from the glass bulb. Luckily the glass was intact. It is the original Philips MW36-44 that came with the set from new. It is a non aluminised CRT.
It measured like new on my tester, even on the lifetime test. So at least the CRT was good.

The rest of the valves, except two, were pulled by the previous "technician" and never put back. So I gave it a complete set of new valves. I was a bit worried that all this would set the alignment far off, but since the valves were already missing, I didn't have much of a choice.

The LOPT had been replaced by a non original type, which later showed didn't fit the set. So I had to chase down one of these. I was lucky to find a spare chassis from it's big brother with the 17" screen, which shares the same LOPT (and chassis). The original LOPT has sort of a "built in" rectifier valve (EY51), which can be difficult to replace. Arching is generally also a problem with these.

Finally I managed to finish up with the chassis. There were a LOT of paper/tar caps! All the electrolytics in the power supply was OK, and also the odd "semi bipolar" electrolytics that are used as booster caps.

Putting it all together and powering it up, I was impressed that the alignment was still perfect. I did not attempt to align anything. Both sound and picture were spot on, which can be tricky with the split carrier sets.

After that, I put the set aside for new projects, and it has just stood there ever since.

A few days ago I powered it up on the variac. I was a bit worried about the booster caps, since it is not really possible to power them up slowly. Once the horizontal osc. is running, the booster caps get charged.
All was working fine though and nothing got abnormally hot. I have now had it running several hours over several days, and it still works perfect.
The picture is excellent. Obviously the CRT is in perfect condition, and focus is even great at the corners. Contrast and brightness is great, but since it is a non aluminised screen, it is best not to watch in broad daylight.

So for this tv, it was easy to get it running again, even after almost ten years on the shelf. I think from now on I will power them up at least once a year.
I will make a post on the next ones as well.

Kind regards,

Jan

[Jan Zodiac]

Here a few pictures from the inside as well. Another thing was the speaker. It had been replaced by a non original type too. I believe I took the speaker from the spare 17" set I mentioned above, to get the whole set as original as possible.

Jan

[Panrock]

Very attractive set. Somehow, could only be 'continental'.

Steve

[slidertogrid]

What a beautiful set! The pictures are simply amazing! Like a monochrome photograph. I have said it before but continental sets were always much nicer to look at than our home market sets. UK TVs of that era were mainly plain brown boxes probably because the room décor of the time was fairly dull and anything too pretty would be judged as gaudy.

Rich

[Jan Zodiac]

This one really does produce an amazing picture. Even if it is only a 14", you quickly notice how absolutely beautiful monochrome can be. The set is well built and the brightness/contrast is so well balanced. This model is my personal favorite. I love the beautiful cabinet. I have the 17" model also, which produces just as beautiful a picture. I will start that one up later on, and attach pictures of course.

I find it very interesting how these things were looked upon in different countries. Here in Denmark, only very wealthy people could buy a set back then (probably the same everywhere). I am sure they already had fancy furniture, so an expensive tv set had to match this. It would be impossible to sell a dull looking set to someone already having design furniture in their home.
Later in the 50's where it became possible for others to buy a set, either a used early one, or a new one bought on instalments, it was never looked upon as gaudy. It was more like the whole street or village found it great, and they all gathered around to watch tv in the home of the owner.
My grandparents bought a tv in 1962, and at that time it was not usual for people in a small village to have tv. My mother told me that on evenings, all kids from the neighbourhood came to watch tv.

Regards,

Jan

[jayceebee]

Definitely has a look of real quality, look at those valveholders for a start.

John.

[simpsons]

I concur with all of the above especially the picture quality and geometry. The straight edges and corner circles which are really circles and not egg shape.

It is difficult to judge how good or bad UK sets of the same era perform given Test Card C isn't quite as demanding for corner geometry but often shows poor horizontal geometry which would shout out on a Telefunken TO5 or similar test pattern.

Just out of interest, what CRT is fitted? Looks flat faced which may explain the good geometry.

Chris

[Jan Zodiac]

Hi Chris,

The CRT is the original MW36-44. The attached pictures show a spare I have upstairs. It doesn't seem to have a flatter screen than the 17" MW43-64 though. It is a 70 degrees CRT of course, making it pretty deep.

Jan

[German Dalek]

Hi,
This is not a multi-standard set!
Multi-standard sets have a 4-position switch in the center!
Because of the knobs it is not made in Germany and because of the
missing 4-standard switch not made in Belgium.
It has to be made in the Netherlands, as far as Philips had no factory
in Denmark.
And yes, they are great sets!

Regards
German Dalek

[agardiner]

Lovely set and a splendid restoration. I don't know about powering it once a year - this sets wants to be enjoyed!

[staticmind]

That's really a beautiful set - it almost look like you stuck in some monochrome photographs. Very sharp. When you wrote "split carrier" - does that mean this is not CCIR system B? Can you just use a normal VHF modulator on it and have picture and sound working?

BTW: If you interested in a free Philips AW53-88 (to replace a Telefunken...), let me know. It produced a fine bright picture the last time it was tested.

[Jan Zodiac]

Dalek,

Correct, it is not a multi standard set. As I wrote I think I have an unrestored set with the multi standard option. At least I am sure I have a spare chassis with that option.
The shown set is made in Denmark for sure. Philips had a factory in Denmark. It started on jan. 1st 1933. They stopped producing radio/tv's in 1963-64 and went on with producing tv tuners. So for 30 years we had a Philips factory.
The "DK" in the model number refers to the danish production factory. "X" is for Netherlands and "D" for Germany.

agardiner,

You are right, I should be using it more. I only use vintage b/w sets in the house though, so at least some are in use frequently.

Troels,

The set uses the standard CCIR B system. Splitcarrier and intercarrier is just how the IF section is made. The earlier splitcarrier system is in general sensitive to temperature drift, and needs to be aligned carefully to get both good sound and picture at the same time. Intercarrier that took over, uses the mixed product of sound and video carrier (here 5,5mHz) and is taken out at the end of the IF strip at the video detector. The sound IF + discr. is then tuned to 5,5MHz. On splitcarrier the sound IF is taken out much earlier in the IF strip, and sound IF is then not a mixed product of the sound and video carrier. In this Philips set the sound IF is 18MHz. It's a bit difficult to explain, but there is no difference in the RF signal applied to the set on either.

Thanks for the offer on the spare CRT. I would be interested, since a friend of mine has a set with a weak Telefunken. At least there is now a change to get a nice picture back on it.

Regards,

Jan

[German Dalek]

Yes, the quality of your pictures is unusual good!
How you made them, with what kind of photographer?
Adjustments?

Regards,
German Dalek

[ben]

It's always a problem when you have many vintage sets to get round to powering them up, especially if they're stacked up or inaccessible. Fortunately most my collection is solid state but even so, several date from the early 70s so are 50 odd years old. Two years or so ago I dragged a load out of a dark corner of the workshop and was amazed that 95% worked fine, despite not being powered up since 2007 in some cases.

[radiomobile]

Very attractive set and certainly a superb picture, helped possibly by the EHT being higher as the replacement lopt was from a 17" set? although obviously no lack of width/height which might have been expected.

[kan_turk]

Lovely, and very interesting, set - as has been said it, and all early sets, used split (AKA parallel) carrier approach where sound IF (18MHz in this case) was tapped off at, or shortly after, the tuner output to feed a separate sound IF amplifier/demodulator at 18MHz. This follows the practice used with AM sound where intercarrier techniques could not be employed and the practice in the US which had started with AM sound and quickly changed to FM, sets initially used split carrier system prior to introduction of intercarrier practice. Frequency drift may not have been the problem feared - as circuitry had become much more stable post WW2. I also believe that the potential drift issue may have over-hyped as I successfully converted a system ‘A’ (405 line, AM sound) to system ‘I’ (625 line, FM sound) in the mid-late 1960s by the simple (OK maybe not that simple) expedient of replacing the AM demodulator with an FM demodulator and changing vision detector for negative vision demod and experienced no problems with frequency drift. S/H 405 line sets were being ‘given away’ at the time and offered the possibility of acquiring (with a little bit of work) a ‘cheap’ tv. -
The other interesting thing about the Philips set is that it has a tuner position for the long vanished Channel 1 - I would love to see a schematic for this set Jan if it is possible to scan

Rgds to all
John

[simpsons]

The German version of the Dutch TDK1420U is known as TD1420A and the schematic is available on the web.

Goes without saying, the set is very upmarket. Push-pull audio with a loudness tap on the volume control. DC to the CRT cathode with a PL83 driving it. Unusual, to my eyes, the horizontal linearity circuit and of course those valve holders which keep everything underneath cool.

Engineering at its best, equalled in the UK by Pye with the Continental series of televisions.

Chris

[stevehertz]

Lovely set, very nice!

[Richard_FM]

Very nice to see.

[Jan Zodiac]

Originally Posted by German Dalek

Yes, the quality of your pictures is unusual good!
How you made them, with what kind of photographer?
Adjustments?

Regards,
German Dalek

I use a Canon IXUS 132 pocket camera which I bought used several years ago. I normally use the "auto" function, and sometimes adjust the brightness (is it called ISO?). I am honestly not much of a photographer, so I just try until I get a decent shot. Sometimes I just use the camera in my phone also. It is even easier. The pictures I took of the tv, shows a very real image. It is just like how it looks for real.

Jan