Some questions about the Philips 2553

Hello,

I have a Philips 2553 radio (working on DC current). I want to restore this radio and get it working again. But the 2 knobs at the left side of the radio are missing. I seached the internet for some pictures of these knobs, but without succes. Can someone provide me a clear picture of the knobs, so that I know what I am looking for ?

Second question: this radio is equipped with 2x B442 and 1x B424 tube from the so called "series 100". These are not ordinary B442 tubes, because there is an additional print on it: "serie 100" (Ordinary B442 tubes are from the "series 250"). Can someone explain where the difference is ?

Best regards,

Pim Vercoulen

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If you look at the model page here, you will find two images from sets with the knobs in place, one submitted by Hugo Sneyers, the other one by John Koster who attributes the image to the collection of one Mr. J. Catteau, Belgium.

I think you will be able to get on from here. It would be interesting to hear if and how you succeeded in producing a replica, or original replacement.

Regarding the 2553 tube line-up I've no information except what can be taken from the documentation:

The part list has the B442 with the remark "gemet." next to them, which I would suspect to mean "gemeten" - measured - while I wonder why the word was shortened at all. This would need some clarification. The "serie 100" may or may not relate to this.

The schema we have is from 1931, the model from 1930. As we date the C443N to 1930, and the tube needs a grid bias of -42V instead of -25V, there is also the question if this model had not been equipped with the C443N instead of the C443 right away.

Regards,
Mark

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Hi Mark,

thank you for your reply. I looked to the pictures of the 2553 here om RM.org, but I can only see one knob very little.

I have the same documentation, this set needs 2x C443N in stead of the 'ordinary' C443. I did make a 'anderungsvorschlag' for the model Philips 2553 here om RM.org, because it says 2x C443 is used in the set.

Regarding the 'gemet' in the documentation, it can mean 'gemeten', but I am not sure. I think it means both B442's have to be paired ? But as I said, I am not sure of this, it is only a guess.

Pim.

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Dear Pim,

ok, the idea was that you can look for the members' pages here in RM, and contact them directly if they should not answer to your request here in the forum.

I am not sure if a C443N can be used in a circuit designed for the C443 without major drawback, so I would argue that either RM data is wrong, or there have been two models (one being in accordance to the documentation a 1931 model with C443N).

We will have to wait what other members can contribute. The tube-line up has been introduced along with the model, and for a reason (supposedly).

Regards
Mark

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Dear Pim,

About the B442 serie question: don't worry, it's a B442, serie may refer to a production date or something so. The best is to check your tube versus theoretical datas on a tube tester, ideally with a tube tester.

Please help also Rmorg: you have a nice photo from a B442, please add it here to our site to the B442 page where I did load the first photo from a B442 some days ago...

Christian ADAM

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Hello Christian,

the series 100 tubes are different from the regular series 250 tubes. The "Staleman Vademecum" does mention the "serie 100" tubes at the Philips models 2533, 2553, 2653, 2524 and 2636. It must be someting special. I own a Philips 2533, with all tubes stamped "serie 100" (Except the ballast tube 1904). See the screenshots of the Vademecum.

Best regards,

Pim.

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Hello,

I received some excellent pictures of the left knobs for the Philips 2553 from Hugo Sneyers in Belgium. I want to thank him for his effort. Also I want to share these pictures with the members of RM.org.

Best regards,

Pim.

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Hi Pim,

I own 2 new B442 without any mark Serie 100 or serie 250. Furthermore in Guy BIRAUD's book "Radio Collectibles Manufactured by PHILIPS" using original reproduction of PHILIPS documents for the tubes, I can find for the 2553 tubes dotation:

(1) B442/O or B442/A (2) B442/O or B442/A (3) B424/A (4) C443N/O (5) C443N/O (6) 1915

So in this well known document there is only a distinction for the base (O = 5 pins = B5, A = 4 pins = B4)

Just a guess: the heater current for the B442 is 100mA, and 250mA for the C443. Is this in relation with Serie 100 for the B442 and Serie 250 for the C443?

Christian

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Hi Christian,

there MUST be a difference between an ordinary B442 and a B442 serie 100. I'd ask some people over here in The Netherlands, but no one can answer my question. Now i'd ask Technical Support of the NVHR (Dutch club antique radio's), maybe they can answer my question. Of course I will keep the forum community informed.

I did contact a Dutchman in Australia for tubes, and he was willing to sell me a Philips B442 serie 100, NOS. See the attached picture. This seems to be a tube from a later production. (Late 30's ?)

Best regards,

Pim.

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Dear Pim,

First the 'Serie 100'. This refers to the serial heater current supply spec. The Serie 100 tubes were made for 100 mA serial heater current. The normal tubes were produced for 4 Volt parallel supply.

The Serie 100 tubes were selected in the Philips factory from normal production runs and marked as serial tubes. The term "Serie" refers to "Serievoeding", the "100" refers to 100 mAmps.

Then the term "Gemet.". This refers to Gemetalliseerd, meaning that there is a thin metallized coating on the outside surface of the tube bulb. Early B442 tubes did not have this shielding feature.

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Dear John,

thank you for the insights. A question that results from reasoning: does this mean that a "regular" B442 would not have been specified to, or used for, 100mA series heating?

Or to put it another way around: to exclude that this was only a variation of the designation of the same tube we would need some authentic data that lists B442 and B442 "Serie 100" as distintictive entries (e.g. a Philips catalogue, prospectus, data sheet etc.)

Do you have a photo of a non-metallized B442 we could attach to a variant?

Thanks,
Mark

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Hello John,

thank you for your answer, I did get an answer too from Albert Z. (by email). It is clear to me now ! So I can use a B442S too instead of a B442 "serie 100" ?

Best regards,

Pim.

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Mark,

Philips used selected (Serie 100) B442 tubes in Philips 2553, Philips 2636 and Philips 2653 radio sets.

The reason for this can be tracked back to heater production tolerances. 4 Volt will not exactly generate 100 mAmps through the filament, nor will 100 mAmps exactly generate 4 Volt over the filament. This filament tolerance has its impact on tube performance. This impact may be relevant or may be not relevant for a given radio set. So my answer to your question is "a regular B442 is not advisable for Philips 2553, 2636 and 2653 sets, but may perform adequate in other sets with serial heating".

Some other complexities exist with respect to serial heating (impact of heater current variations on tube performance and impact of cathode current on heater current), but heater tolerances are dominant here.

Today I noticed a Philips B442 (Serie 100) unshielded tube at the NVHR swap meeting in Driebergen:

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Geachte John,

sorry for being the critic that I am, but I think I can identify remains of metallic shielding on this tube, i.e. under the top connector base to the right, a greater area on the left side, and some flakes in the middle. Am I mistaken?

I will check with our tube admins if the "serie 100" deserves an entry as a tube variant.

Best regards
Mark

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Mark,

There are no indications of metallic shield or paint on this tube. The craquelé in the middle is inside the tube, at the edges of the getter area.

The Philips logo and Type number are intact, and were directly written on the glass. The Serie 100 label is also directly written on the glass, see the photo.

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Dear Pim,

following this discussion we now have a B442_Serie100 tube that can be selected for the relevant models. So if you like, you can upload your pictures to the new tube, and make a change proposition on the model pages in question (as per your post #6, and the additional info from John Hupse).

I also would like to ask you to post the pictures of the knob you received as a forum entry via the model page of the 2553 so we have that as a stand-alone information. Remember, it's not needed to upload the images again, just select them from the storage. This can be followed by deleting post #6, #16 (this one), and follow-ups, so the remaining thread can be nicely moved either to the tube B442, to the new tube B442_Serie100 or to the 2553 - it's your decision. I will interlink the topics afterwards.

John, as you have brought up the topic of the unshielded B442 initially, I think you might want to create a variant for the B442_Serie100 and attach the picture to it, maybe with a bit of explanation.

Thanks and all the best,
Mark

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Dear Mark,

thank you for creating a new entry for the tube B442 serie100. I have more serie100 tubes (e.g. B415 serie 100 etc.). When I have some spare time I will create a new entry for it. I now uploaded some pictures of the NOS B442 serie100 I did receive today from Australia. When needed I can also take some pics of the original box, but I don't know if that is interesting to add to the tubedata.

I also will add the pictures of the knobs to the Philips 2553.

<Edit 27-06-2007 @22:17>:

I cannot add new tubes, can you please add them ?

B424_SERIE_100

B543_SERIE_100

B415_SERIE_100

</edit>

Best regards,

Pim.

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