Old Philips paper capacitors decoding (50's) - UK Vintage Radio Repair and Restoration Discussion Forum

normende · 18th Mar 2014, 7:29 pm

Hi,

I am restoring a black and white projection TV Philips TX1714 (or TD2312 European version) from 1952, and I want to replace all the paper capacitors.

I couldn't find how to decode the rated voltage on them.

On this website, there is an article about capacitors in which they are mentioned to be hard to decode (check the black-coated Philips caps):

http://www.vintage-radio.com/repair-...apacitors.html

As this is an european set (from the Netherlands) maybe some of you have hands-on experience with sets from the 50's and already know how to read the codes. I couldn't find anything online.

For example:

5K6P 2.2
5K6P 7.1
5K6P 0.1
5K6P A.1
L5K6P 2.2
H5K6P 1.1

And so on....

Some of them don't have a letter in the beginning of the code, some other do. All of them have the "P" letter after the capacitance value (maybe it is the tolerance?).

The last numbers (separated from the capacitance value) may refer to the voltage? I couldn't find the logic to find it out. Some of them have a "delta" (triangle drawing) sign and after that it comes a dot and a number. Like "A.1" (but it is not a letter, it is the delta sign).

Thanks a lot in advance!

Jac · 18th Mar 2014, 8:59 pm

Some info:

5K6 is 5.6 nF - 400V (i.e. no letter)
L5K6 is 5.6 nF - 125V (letter L)
H5K6 is 5.6 nF - 600V (letter H)
Letter S would be 800V and T is 1000V.
The letter P in 5K6P indeed means a tolerance, in this case of +/- 20%
An A in that position means +/- 10%.

Markings like 2.2 etc after the capacitance/voltage code is just a production code, and has no practical meaning.

The size of the capacitor also gives you an indication of the rated voltage.

Hope this helps.

Jac

normende · 18th Mar 2014, 9:50 pm

Thanks a lot! This is exactly what I was looking for.

I am a bit afraid of manipulating this set... I've been thinking of this today.

The separated high voltage chassis has a special sealed can with a flyback transformer, 3 rectifier tubes and capacitors all immersed in oil which I was told is PCB.
Some of this oil is out on the upper side of the can, it seems it has leaked from the HV connector out.
I don't know if I should go on with the restoration or put everything back. I don't even know if this can is operational, and I will have to replace like 25 electrolytic caps plus a lot of paper caps maybe for nothing or with the risk of having problems because of the PCB.

Do you have any experience with this type of set? Thanks!

Jac · 19th Mar 2014, 9:01 am

I have restored some Philips TX701 sets, which are roughly the same.
25 years ago I had the transformer oil of exactly such a can tested and the outcome was that it did not contain pcb.

The high-voltage unit can be tested separately from the set.
It generates 25 kV (or a little less) for the MW6-2 projection CRT.
The transformer-can can be restored.
You can replace the diodes and capacitors if it is not working anymore.
The windings usually are in good shape and should not be touched.
All circuitry should be immersed in the oil. Some wetting on the top does not necessarily mean that the oil level is too low.
In one can I restored, I have replaced the oil by 3M Fluorinert FC-43, just because I had some of that liquid at hand.
Works perfectly.

Check the large green resistors; usually one of them (or all) is open circuit.
The black paper capacitors should be replaced. All valves should be in top condition for reliable HV-generation.
There are not too many components in the HV-unit, so it is wise to check each and every one of them.

Jac

normende · 19th Mar 2014, 1:53 pm

Thanks Jac,

This is great news!

I hope the tubes on the HV unit are fine. Here, getting these kind of spares (old tubes for example) is almost impossible because our market has always been small, and to make things worst imports are closed so I can not receive a package with tubes from abroad...

In the service manual of the set (in German unfortunately) it says something like the unit can not be repaired, and even that if you take the HV connector out the unit becomes unusable. All these discouraged me but your experience says something different (maybe all that was only to sell you the can as a spare).

Do you know where I can download the version of the manual in English? I translated the manual from German using Google but it did not work very well.

So if I understand correctly, I can just plug (after replacing the caps and checking the resistors) the HV unit to 220V and see what happens, independently from the other chassis and the CRT, right?

I can't find here the capacitors rated 500/550V (max. 450V). Where they overrated from the factory (voltages across the set seem not to go above 450V) and I can use 450ÑV or should I connect two in series to get 500V?

One more, there is a cap in the HV chassis named after "bipolar" and isolated from the can. That one also I can not find here. In the schematics it appears as a regular polarized cap. Is there any alternative for this one?

Jac · 19th Mar 2014, 7:28 pm

The HV-can certainly was intended to be replaced as a whole.
No service technician in his right mind would consider restoring it

But we do not have an hourly rate for our own restorations, so we can spend the required ridiculous amount of time necessary.
The can cannot be opened that easily, but it certainly is doable.
I should have some photos of the interior; that always is helpful, I find.
PM me your email-address and I'll see what I can turn up.

It could very well be the case that the electrolytics do not need replacing.
No such high voltage occurs during normal operation, so in case of looking for replacements you could start with lower voltage ones (385 or 400VDC). Just measure the voltage on them during start-up and during operation, and you have a fair idea of the actual requirements.

Be careful if you connect the CRT, a burn-in of the screen is easily done, despite the "security"-circuit on the main chassis (which should cut off the beam current in case the deflection fails).

You can load the HV with a few hundred Meg Ohms (a high-voltage probe might be suitable for that) and start the unit up independently of the TV-chassis.
Mains voltage indeed is 220VAC.
You should hear a whistle when it is operating. 1 kHz or somewhat less. Quite irritating...

E-mail me the service manual and I'll see if there are differences with the circuitry of the projection sets I restored. I can read German, so no problem there.

Jac

normende · 21st Mar 2014, 2:46 am

Thanks Jac!! Your tips are great info for me.

I will send you a PM. Next week I hope to be able to recap the set with new paper caps and do a soft start to rebuild the electrolytics.

I hope the can doesn't need repair!

normende · 24th Mar 2014, 1:58 pm

I started replacing the paper caps. I had to make arrangements of different caps to get the exact values (and combine polyester and ceramic ones to get for example 1.8nf). In a pic I show the progress.

I checked other components. What I found defective so far was a wire resistor feeding the focus coil open, and a coil that goes to the cathode of the CRT. I also replaced only two electrolytic caps, the ones (in parallel) right after the rectifiers which visually were not OK (some leakage at the top could be noticed).

I don't have the specs of the coil, I have other coils I got from other old TVs.... (see the last picture). Can I replace this one with some of the others I have? I don't have a measurement instrument to check their value in mh...

18th Mar 2014, 7:29 pm	#1
normende Triode Join Date: Mar 2014 Location: Buenos Aires, Argentina. Posts: 22	Old Philips paper capacitors decoding (50's) Hi, I am restoring a black and white projection TV Philips TX1714 (or TD2312 European version) from 1952, and I want to replace all the paper capacitors. I couldn't find how to decode the rated voltage on them. On this website, there is an article about capacitors in which they are mentioned to be hard to decode (check the black-coated Philips caps): http://www.vintage-radio.com/repair-...apacitors.html As this is an european set (from the Netherlands) maybe some of you have hands-on experience with sets from the 50's and already know how to read the codes. I couldn't find anything online. For example: 5K6P 2.2 5K6P 7.1 5K6P 0.1 5K6P A.1 L5K6P 2.2 H5K6P 1.1 And so on.... Some of them don't have a letter in the beginning of the code, some other do. All of them have the "P" letter after the capacitance value (maybe it is the tolerance?). The last numbers (separated from the capacitance value) may refer to the voltage? I couldn't find the logic to find it out. Some of them have a "delta" (triangle drawing) sign and after that it comes a dot and a number. Like "A.1" (but it is not a letter, it is the delta sign). Thanks a lot in advance!

18th Mar 2014, 8:59 pm	#2
Jac Heptode Join Date: Jun 2006 Location: Eindhoven, Netherlands. Posts: 642	Re: Old Philips paper capacitors decoding (50's) Some info: 5K6 is 5.6 nF - 400V (i.e. no letter) L5K6 is 5.6 nF - 125V (letter L) H5K6 is 5.6 nF - 600V (letter H) Letter S would be 800V and T is 1000V. The letter P in 5K6P indeed means a tolerance, in this case of +/- 20% An A in that position means +/- 10%. Markings like 2.2 etc after the capacitance/voltage code is just a production code, and has no practical meaning. The size of the capacitor also gives you an indication of the rated voltage. Hope this helps. Jac

18th Mar 2014, 9:50 pm	#3
normende Triode Join Date: Mar 2014 Location: Buenos Aires, Argentina. Posts: 22	Re: Old Philips paper capacitors decoding (50's) Thanks a lot! This is exactly what I was looking for. I am a bit afraid of manipulating this set... I've been thinking of this today. The separated high voltage chassis has a special sealed can with a flyback transformer, 3 rectifier tubes and capacitors all immersed in oil which I was told is PCB. Some of this oil is out on the upper side of the can, it seems it has leaked from the HV connector out. I don't know if I should go on with the restoration or put everything back. I don't even know if this can is operational, and I will have to replace like 25 electrolytic caps plus a lot of paper caps maybe for nothing or with the risk of having problems because of the PCB. Do you have any experience with this type of set? Thanks! Attached Thumbnails

19th Mar 2014, 9:01 am	#4
Jac Heptode Join Date: Jun 2006 Location: Eindhoven, Netherlands. Posts: 642	Re: Old Philips paper capacitors decoding (50's) I have restored some Philips TX701 sets, which are roughly the same. 25 years ago I had the transformer oil of exactly such a can tested and the outcome was that it did not contain pcb. The high-voltage unit can be tested separately from the set. It generates 25 kV (or a little less) for the MW6-2 projection CRT. The transformer-can can be restored. You can replace the diodes and capacitors if it is not working anymore. The windings usually are in good shape and should not be touched. All circuitry should be immersed in the oil. Some wetting on the top does not necessarily mean that the oil level is too low. In one can I restored, I have replaced the oil by 3M Fluorinert FC-43, just because I had some of that liquid at hand. Works perfectly. Check the large green resistors; usually one of them (or all) is open circuit. The black paper capacitors should be replaced. All valves should be in top condition for reliable HV-generation. There are not too many components in the HV-unit, so it is wise to check each and every one of them. Jac

19th Mar 2014, 1:53 pm	#5
normende Triode Join Date: Mar 2014 Location: Buenos Aires, Argentina. Posts: 22	Re: Old Philips paper capacitors decoding (50's) Thanks Jac, This is great news! I hope the tubes on the HV unit are fine. Here, getting these kind of spares (old tubes for example) is almost impossible because our market has always been small, and to make things worst imports are closed so I can not receive a package with tubes from abroad... In the service manual of the set (in German unfortunately) it says something like the unit can not be repaired, and even that if you take the HV connector out the unit becomes unusable. All these discouraged me but your experience says something different (maybe all that was only to sell you the can as a spare). Do you know where I can download the version of the manual in English? I translated the manual from German using Google but it did not work very well. So if I understand correctly, I can just plug (after replacing the caps and checking the resistors) the HV unit to 220V and see what happens, independently from the other chassis and the CRT, right? I can't find here the capacitors rated 500/550V (max. 450V). Where they overrated from the factory (voltages across the set seem not to go above 450V) and I can use 450ÑV or should I connect two in series to get 500V? One more, there is a cap in the HV chassis named after "bipolar" and isolated from the can. That one also I can not find here. In the schematics it appears as a regular polarized cap. Is there any alternative for this one?

19th Mar 2014, 7:28 pm	#6
Jac Heptode Join Date: Jun 2006 Location: Eindhoven, Netherlands. Posts: 642	Re: Old Philips paper capacitors decoding (50's) The HV-can certainly was intended to be replaced as a whole. No service technician in his right mind would consider restoring it But we do not have an hourly rate for our own restorations, so we can spend the required ridiculous amount of time necessary. The can cannot be opened that easily, but it certainly is doable. I should have some photos of the interior; that always is helpful, I find. PM me your email-address and I'll see what I can turn up. It could very well be the case that the electrolytics do not need replacing. No such high voltage occurs during normal operation, so in case of looking for replacements you could start with lower voltage ones (385 or 400VDC). Just measure the voltage on them during start-up and during operation, and you have a fair idea of the actual requirements. Be careful if you connect the CRT, a burn-in of the screen is easily done, despite the "security"-circuit on the main chassis (which should cut off the beam current in case the deflection fails). You can load the HV with a few hundred Meg Ohms (a high-voltage probe might be suitable for that) and start the unit up independently of the TV-chassis. Mains voltage indeed is 220VAC. You should hear a whistle when it is operating. 1 kHz or somewhat less. Quite irritating... E-mail me the service manual and I'll see if there are differences with the circuitry of the projection sets I restored. I can read German, so no problem there. Jac

21st Mar 2014, 2:46 am	#7
normende Triode Join Date: Mar 2014 Location: Buenos Aires, Argentina. Posts: 22	Re: Old Philips paper capacitors decoding (50's) Thanks Jac!! Your tips are great info for me. I will send you a PM. Next week I hope to be able to recap the set with new paper caps and do a soft start to rebuild the electrolytics. I hope the can doesn't need repair!

24th Mar 2014, 1:58 pm	#8
normende Triode Join Date: Mar 2014 Location: Buenos Aires, Argentina. Posts: 22	Re: Old Philips paper capacitors decoding (50's) I started replacing the paper caps. I had to make arrangements of different caps to get the exact values (and combine polyester and ceramic ones to get for example 1.8nf). In a pic I show the progress. I checked other components. What I found defective so far was a wire resistor feeding the focus coil open, and a coil that goes to the cathode of the CRT. I also replaced only two electrolytic caps, the ones (in parallel) right after the rectifiers which visually were not OK (some leakage at the top could be noticed). I don't have the specs of the coil, I have other coils I got from other old TVs.... (see the last picture). Can I replace this one with some of the others I have? I don't have a measurement instrument to check their value in mh...