philips: Operation of the Silent tuning switch

Hello

This is the radio that has the silent tuning option that uses a brake operation when a station is found; audio then being restored.  Philips called this Auto mode which it isnt really.

All I need to know is how this is selected on the Monoknob?  I believe there to be a lever, which operates a switch wafer, by Bowden cable, and a sprung push button. The switch is first operated and then the push button depressed in my thinking and not having the radio.

 Is this correct?

A picture of this would be really useful.

thanks Gary Tempest

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Hello Mr. Tempest

I made some investigations on my own Philips (NL) 890A.

The drawing above shows how on the tip end of the inner knob a small member can be moved.
This activates switch C which is mounted above the chassis right behind the LF output transformer.

With this switch the silent tuning option can be enabled or disabled. The connection to the speaker is done by a contact of the Master Relay (Turmrelais).

Kind regards.

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That is most kind, thank you.

I have never seen an 898A and although the principle is the same the D53 does things in a different manner.  However that push switch will be the same on both.

It clears up one mystery but I still have another.  On the D53 there are 3 wafers on the waveband switch and another that has to be operated before Auto mode can be engaged.  It is marked “33” on the layout diagram and is worked by a mechanical cable (“Bowden cable” in English).  Please see picture.

But where is the lever that operates that?  The switching on the schematic for the 898A is not the same and so it may take a D53 owner to solve this one for me?

It is possible that it is combined, 3 positions, with a switch for pick up operation but I’m not sure about that.

I had one on sale or return and did return it.  There was just too much wrong with it to restore.

However, I did re-draw the schematic and have worked out most of how it works for an article in the BVWS Bulletin.

Once again many thanks, I have been puzzling for some time now  Gary

Gary Tempest

• D53 layout diagram (132 KB)
• D53 layout diagram (132 KB)
• Picture of Philips D53 under chassis (216 KB)

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I have just looked at the MonoKnob diagram again in the D53 Service Manual and can see a box on the left hand side (below "35") that must be for operation of the remote switch wafer by mechanical cable. 

Your 898A has that same box so it becomes a simpler question:  where is the lever for that on the MonoK assembly?

thanks Gary 

• D53 MonoKnob diagram (204 KB)

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Hello again

Don't be mistaken, I have the Dutch Philips 890A (not the 898A) in my possession, which is in a very bad condition and not in working order. Except for the type of valves there should be not much differencies between the German one.

To answer your question, the lever which operates the waveband switch is mechanical tied to the outer knob! In my picture marked in blue.

,,,

For further clarification, here an overview of the combined possibilities of the gadged "Monoknob" 

Kind regards

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Thank you once more.  Slowly the light is beginning to show.

But another question please: so the remote switch wafer is lnked to the waveband switch, I started off thinking that and then dismissed it.  But how many positions does that switch have?

I guess it will be L, M, S and possibly Pick Up.  Is this correct? So a little more investigation into my understanding of the circuit. 

If you would like to read my Draft article I could send it to you but I know its hard struggling with the English.  It was hard for me when I was learning German, many years ago, and no one wants to speak it to you when you get there  LOL

thanks for your patience.

The killer on these radios are the potentiometers. I made gearboxes for modern pots on my D57, I think its posted.  Super sounding radio when restored.

Gary

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Hello again.

I had not found the 890A which has most interesting postings.  Circuit looks initially very close to the D53 but I will study it more.

Some technical description as well, I will try to understand some of it with Goggle translate and compare to my thinking.

thanks for the link.

Gary

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Your question was:

"...so the remote switch wafer is linked to the waveband switch, I started off thinking that and then dismissed it. But how many positions does that switch have?"

The main waveband switch (outer knob) has 4 positions: S M L and Pick-Up.
The remote switch has 3 positions because the Silent Tuning remains in action only for the medium and long wave band.

Wolfgang

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Once again, many thanks

Gary

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