saba: Saba 300 9T, really it needs adaptation for line

Respected Members,
Recently I have acquired two Saba radios: Continental 410US and 300 automatic 9T.  Two export models that correspond respectively to the Freiburg Vollautomatic 14 and Meersburg Automatic 9.  These models were designed to work with 60 Herz power supply.  The original documentation for the two radios suggests hardly to carry out an "Adaptation for line frequency" changing the two motor capacitors from 0.22 mf to 0.3 mf if the model is going to utilize with 50 Herz power. 
I live in Chile where the power transmission systems is 220 volts, 50 Hz. and the two radios have a perfect and precise behavior in their motor tuning system without to have changed the motor capacitors.  My question to the forum is: Which is the technical argument that justifies this change if the motor tuning behaves of equal form with 60 or 50 Herz power supply? 
Respectfully,
Bruno Gandolfo. 

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Hello Mr. Gandolfo,

when after 3 Day's no other one answering here, i give you my Statement to this Problem
via Mail. My english is not good enough for international readings. 

Hans M. Knoll

 

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Dear Mr. Gandolfo, Dear Mr. Knoll,

maybe i am not the Number one Expert on this, but my English hopefully will be good enough to understand.

The Saba Tuning Motors consist of 4 Coils, electrically grouped together to have one Group 90 Deg rotated to the other Group.

One Group is feed with apx 250V AC from the Main Transformer, in series with a Capacitor.
The other Group is feed from a tube Stage, and there is a Capacitor in Parrallel to the Motor Coils.

This Arrangement makes the Current ( and this making the Magnetic Field ) going earlier in one Group, and going later in the other Group. As a Consequence the Magnetic Field is rotating, and this makes the Rotor rotate too.

As the Current trough a Capacitor is depending on the Frequency, Saba decided to adjust the Values for different AC Frequencies.

There is also a Text in German in the Radiomuseum, where Part 3 describes it in Detail.

http://www.radiomuseum.org/forum/saba_3ds_freiburg_automatic2.html

Best Regards,

Henning Oelkers, Berlin

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Hallo Herr Knoll,
Thank you so much for your interest in my question.  I have read many of your articles and I know that your English is better than mine.  I expect to know and to enjoy your answer. 
Bruno.

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Dear Mr. Oelkers

Thank you so much for its kind answer.  I understand the technical base as works the motor  tuning system.  I will study in detail the text in German. 
The 300 aut.  9T was  repaired by my esteemed friend Roberto Sarbell in Marietta, USA and the radio worked perfectly in 110 volt / 60 Hz and of equal form does it in my workshop with 220volts / 50 Hz!. with the same motor capacitors.  Then the recommendation of the manufacturer to change the capacitors does not have practical justification? 
Respectfully,
Bruno.

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Dear Mr. Gandolfo,

I am not 100% shure, but i would recommend to change the Capacitors to the correct Values.
As You have seen, the Motor works fine right now, but i think You don't know for shure, if all the Currents and Voltages are within the Limits.

There is definetely a good Reason for SABA to recommend to have different Values for 50 and 60Hz.
By Replacing the Capacitors You will be on the safe side, and no one of the Parts is in an overload Condition.

Hope this helps.

If You have Problems understanding the German Text in RM about this, i can try to translate this for You, and send via e-mail

Best Regards,

Henning Oelkers

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Dear Mr. Oelkers,
I understand your suggestion to change the two motor capacitors seeking a technical perfection although in the routine use be not declared an evident difference. 
The translation of the text in German is very laborious using Babel Fish translator since the original text does not permit copy & paste.  I will remain very thanked if you sends me the translation to my email (brugan@vtr.net). 
Thanks by your interest in my question. 
Best regards, Bruno.

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Please see also  post from Mr. Schoen 

here:

Hans M. Knoll

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Rebuilding devices Automatic of Saba from Europe on USA

Here one finds SABA original documents   in order to bring a Europe model onto US requests.

It is treated the reconstruction of the VHF field  and the condensers at the engine control.

In addition the TB- devices TK125-S, TK125-4, TK220-S

 

see here:

 

regards h.m. knoll

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Hello Hans,

Thank you so very much by the valuable documents. The Saba Service Instruction would be an interesting informations to all out of Germany Saba radio collectors.

Thanks again, Bruno.

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