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-   -   1948/1949 Philips type 520A television and radio (https://www.vintage-radio.net/forum/showthread.php?t=128382)

Aerodyne 3rd Aug 2016 8:44 am

Re: 1948/1949 Philips type 520A television and radio
 
Would someone kindly elaborate on the 'clash' between Mullard and Philips, as mentioned in this thread?
Tony

Maarten 4th Aug 2016 12:30 am

Re: 1948/1949 Philips type 520A television and radio
 
I would like to know as well. Mullard was a full subsidiary of Philips from 1927, but of course they had their own design staff as was usual for many Philips companies (internal cooperation and internal competition were both stimuli for innovation).

Heatercathodeshort 4th Aug 2016 7:16 am

Re: 1948/1949 Philips type 520A television and radio
 
Eindhoven insisted in designing the UK television receivers that were built at Mitcham.
This caused difficulties at the factory due to the fact that actual live transmissions were not available in the Netherlands and receivers suffered from design faults. Modifications were constantly taking place and the UK team threatened to withdraw their cooperation. Philips eventually gave in and all receivers from the 520A were designed very successfully by the British design team.
Back in the shop days I had several customers that worked at the Philips Mitcham works as it was known in the late 1940's. It was very informative chatting with them. In the end the difficulties were resolved resulting in a fine range of British receivers designed at the Mitcham Works continuing into the early 80's. John.

Jac 4th Aug 2016 7:46 am

Re: 1948/1949 Philips type 520A television and radio
 
That's interesting John.

Do you know if the 383A and 663A were made before or after the 520A?
I have both a 383A and 663A, and there is no M in the serial number.

Jac

FERNSEH 4th Aug 2016 8:14 am

Re: 1948/1949 Philips type 520A television and radio
 
Hello Jac,
The 383A and 683A have much in common with certain pre-war models like the 2405 etc. According to the service data the 520 was designed to receive the Birmingham transmitter so it's safe to say that it was on sale after the 383A had gone out of production. The 385A was marketed at same time as the 520A.

DFWB.

Aerodyne 4th Aug 2016 8:23 am

Re: 1948/1949 Philips type 520A television and radio
 
Thanks for that sidelight on Philips' centralised approach, John.
Tony

grahamperrin 4th Aug 2016 8:29 am

Re: 1948/1949 Philips type 520A television and radio
 
Thanks folks.

Quote:

Originally Posted by Maarten (Post 867553)
The stamping machine was probably adjusted to non-pre printed type plates so for practical intents and purposes I would consider this a single M.

+1

I had the same guess about pre-printing.

Jac 4th Aug 2016 8:35 am

Re: 1948/1949 Philips type 520A television and radio
 
Thanks David,

Yes, you're absolutely right. I should have noticed that myself!
Were the 463A and 563A manufactured earlier than the 383A and 663A?
Or about the same time?

Thanks.
Jac

grahamperrin 4th Aug 2016 11:56 am

Re: 1948/1949 Philips type 520A television and radio
 
Quote:

Originally Posted by Maarten (Post 867553)
… the type plate's article code A1 872 23.0/A …

Might the tail of that be 23.O/A (uppercase o, not a zero)? On one hand, the character is more rounded than I would expect for a 0; on the other hand, I have no other plate (with other examples of the typography) to compare against.

OVERZEE/ANGLO maybe?

Maarten 4th Aug 2016 1:26 pm

Re: 1948/1949 Philips type 520A television and radio
 
Not based on typography but on the construction of the Philips code system, the digit behind the . is the revision number. If the design is changed, it is incremented. After it reaches 9, a new code number is used.

It is indeed true that various different type plates were used for different destination markets, but they had a different code number within the same series and not simply a different revision number. As far as suffixes go, I'm not exactly sure why and how they were used. Speculation says the /A may have something to do with the pre-printed M which may or may not have been pre-printed at the same time the rest of the plate was printed.

To illustrate, some similar code numbers of type plates:
A1 871 99 "PHILIPS Made in Holland/Importe de Hollande" with Nemko/Demko approval marks (used on some 1948/1949 export radios)
A1 871 99.0 "PHILIPS Made in Holland/Importe de Hollande" with Nemko/Demko approval marks (used on various general market and export sets around 1940-1947)
A1 871 991 "PHILIPS Made in Holland/Importe de Hollande" with Nemko/Demko approval marks (used on some 1947-1948 models for general markets)
A1 872 23.0/A the plate on the 520A/15 from around 1949
A1 872 27.2 plate on GM4198 measuring equipment

The code number series starting with A1 wasn't used for very long (approximately 10 years with a war in between) so those are the only examples I have but the same principle applies to other type plates and in general to all code numbers from the early 1930's to the early 1960's. I don't know the (probably small) differences between the various A1 871 99 versions so I'll have to compare pictures.

Heatercathodeshort 4th Aug 2016 1:41 pm

Re: 1948/1949 Philips type 520A television and radio
 
The first Philips television manufactured after the war as far as I know is the series with voltage doubler HVR2 rectifiers developing EHT from the pulse available on the anode of the line output valve. No EHT mains transformer was employed despite the chassis containing several large transformers and HVR2 rectifiers.
The first true flyback models had an oil filled transformer[?] and two EY51 EHT rectifiers again in a voltage doubler circuit. Their heaters were powered from the flyback transformer unlike the early model that had the two HVR2 rectifier heaters powered from a specially insulated mains transformer.
It would appear that the 520 was sandwiched between the 385/485 series and the 1100, a truly incredibly reliable receiver. Maybe I'm wrong. John.

Jac 4th Aug 2016 3:10 pm

Re: 1948/1949 Philips type 520A television and radio
 
1 Attachment(s)
Thanks John,

That makes it even more complicated.
The 383A/663A has a mains transformer and voltage doubling with 2x HVR2 from the anode of the line output valve.
To me it is not clear how the line output transformer itself is built, because it is in a sealed 'box'. See attached picture.
(I have no X-ray equipment to look into it.)
It might very well be a laminated iron cored transformer with several wave wound coils, as was not unusual at the time.
Perhaps there is petrolium jelly in the box, as is in the transformer of an experimental Philips projection receiver of an earlier date.

The 385U (no mains transformer - 2x EY51) is dated at October 1949 according to the Trader Sheet (nr 993).
The 1100 ditto August 1951 (Trader Sheet 1051).
The 383A/663A certainly is before the 385U.
Unfortunately I could find no Trader Sheet for the 520A of Mullard equivalent.
There must be date codes in it it somewhere however. Perhaps on the CRT as well.
The Wireless and Electrical Trader has an advertisement of the 383A at January 8, 1949.

The 520A has, as David pointed out, a Birmingham version.
The 383A/663A has not.

So the sequence looks like this:
* 463A + 563A (date??)
* 383A + 663A (early 1949?)
* 520A (1949?)
* 385U (Oct 1949)
* 1100 (Aug 1951)

Jac.

FERNSEH 4th Aug 2016 4:43 pm

Re: 1948/1949 Philips type 520A television and radio
 
I'm certain that all the models marketed before the 520A were designed to receive the AP transmitter, no Birmingham versions. Is it possible the models 463A and 563A were nothing more than alternative cabinet presentations of the 383A?
Jon's 563A: http://www.thevalvepage.com/tv/philips/563a/563a.htm
The date code on the two TCC Visconol capacitors in the EHT doubler circuit is 477, July 1947. I'm trying to determine the date codes on the Philips black tar "goudron" capacitors. More about that later.
The contributor to this French TSF forum has his problems with those condos au goudron:
http://www.doctsf.com/forum/viewtopi...=8860&start=12

DFWB.

Jac 4th Aug 2016 6:06 pm

Re: 1948/1949 Philips type 520A television and radio
 
Good evening David,

Yes, that's very well possible.
Although it is not clear to me what the difference between a 463A and a 383A is. I couldn't find a picture of a 463A.
The service manual for the 383A/663A refers to the manual of the 463A/563A for the circuit description.
Do any 463A's actually (still) exist?

I think the visconols in my 383A have 4811 as date code.

Regards,
Jac


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