philips: 641M; and DT4 tube

I have this radio. My model is without tubes and was probably modified.
I haven't found any information regarding the DT4 tube, which is reported to be used only in this radio (according to Erb's book and to the schematics).
Does anyone know some more information or a replacement for this tube? And some photo of the cabinet and/or the chassis?
Thanks,
Alessandro

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Dear Sir,

Only two possibilities just.

The model is on a Hungarian isued service manual Philips from 1935. Possible it was made in the Philips hungarian mother company Budapest. I find it there, possible see in here http://www.hifiklub.hu/Philips/philips.html You find 641M shema on it = in radiomuseum.org shown! I think Mr Herczeg or Mr Apsitos can help, the  two gentlaman have more experience pre War models. May have information tube DT4 and more.

About picture http://galeria.olh.hu/CD/k-tart.html In Philips at here ,You can find all the pictures/graphic of Hungary made radios near 1100. Unfortunately Philpis is not used type no. only "fantasy names" is the early times. Please try it, maybe You find it by a NAME!

Best Regards

Géza Bordi

 

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Thanks for your reply.
The radio was made in Italy by Philips Italia (Monza - Milano). Unluckly the links aren't working: maybe are they wrong?
Anyway the DT4 tube was made from Zenith and I found a replacement.

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May like http://www.hifiklub.hu/ and You have to roll down right /under Mr.Apsitos I pic and click/ PHILIPS RAJZ /, slow but work.The other like http://galeria.olh.hu/orh/tart-a.htm And HUNGARIAN RADIOS menu I hope as this working.Im not find any Philips radio made in Hungary 1936-48 is built in DT4 tube !!! I think I see all.Sorry, I dont know much about Zenit and Italian Philips models /It is much easy for You then for me... / Only some other, D type tubes seria,  I finid in later models under WWII. If I see some about the tuda DT4 Ill send it.

Best Regards 

G Bordi

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Dear Jacob.
thanks for replying.
We are on the right way: I think that WE37F is not just a good replacement for the tube I need, but is the right tube for my radio. In fact I was wondering why the socket base on the chassis was an Europe side contact base P, while the DT4 had an Europe 7 pin C7A, so in later models this tube was replaced with the successor WE37F.

This is DT4 socket:

About DT4, please see also the attachments here:

• Characteristics of the tube are in the page: Ottodi (rete); Duo-Diodi, Diodi-Triodi e Diodi-Tetrodi (Binodi) (rete);
• Whereas the socket is in the last attachment.

I'd bet that this radio has been built in Italy only, as some of Philips Radios which are listed in German Philips catalogue (for instance, those with tubes with Italian WE names, like 651 and 653) - but schematics were also in German.

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Dear tube and radio friends,

I have found some datas for the Zenith DT4 in a Hungarian book and listed here in the tube data page. The base of Mr. de Poi is correct, thank you.

Another nearly similar tube is the DT3 from the maker Zenith. It have only one diode.

Have a nice day,  H.-T. Schmidt

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It looks like I'll have to look for a WE37F.
Yes, also the DT3 is listed here: DT3
while its socket is no. 75 here: socket

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Hello Mr. De Poi

I think, another possibility is a AF2, rebased, with 2 germanium diodes.

Regards,  H.-T. Schmidt

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Yes, this is what I've done indeed, to make the radio working again.
So, I'm not in a hurry to find the replacement, but would prefer having it.

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Indeed, Zenith was taken over and merged into Italian Philips sometime in that period. Also, both had their plant in Monza (close to Milan).
Probably the original tube lineup is the one with DT4, whereas latter series should have been using WE37F. There are also some variants of 641M with and without bakelite LS grill.

8/5/2007:
WE37F definitely suits my radio (I could finally remove the diodes and restore the circuit as it was before) which probably had been using this tube since beginning: the socket the radio is using is Europe-side contact base (not DT4's one). The radio works fine with the WE37F. Thanks for your help in solving this matter!

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