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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc.

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Old 17th Oct 2016, 9:04 pm   #61
Copey84
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Default Re: Philips reel to reel

Thanks Tony will let you know how I get on.
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Old 29th Oct 2016, 10:10 pm   #62
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Default Re: Philips reel to reel

Hello, to anyone still interested in this thread, i just got back to working on the recorder today.
I built the signal generator and applied the sine wave to the circuit at the volume control pot as suggested in previous post. With the play back button closed the signal appears at speaker. Measured with oscilloscope having earth connection connected to the earth of signal generator.
Worked my way up circuit to the speaker from volume control and all ok. Then went to base of T1 and worked up to volume control, again ok.
Thought I'd try signal with playback open, expected not to see signal at speaker however it still appeared.
From T1 up to speaker the signal is present when playback open, maybe this explains why there's noise in speaker before play back is closed.
Does this mean the fault is in switches? And if the signal is reaching the speaker in playback why is there only distortion?
As always appreciate any replys.
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Old 29th Oct 2016, 11:52 pm   #63
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Default Re: Philips reel to reel

It might be that the mechanical action of the switches is faulty, causing some of the playback connections to stay closed when the machine isn't playing. This is going to be complicated to trace. I'd go through and check each switch section with the machine in play, and then in record. Take the batteries out for this.
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Old 30th Oct 2016, 1:07 am   #64
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Default Re: Philips reel to reel

Hi sue, will check continuity of switches again. If it is switches the fault is most likely in the mechanism that is operated by record button. Is it easy to take apart an reassemble? No instruction in service manual
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Old 30th Oct 2016, 4:44 am   #65
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Default Re: Philips reel to reel

All I've got is the circuit diagram, so I can't say. My EL3586 only had perished rubber problems, and I didn't have to investigate the switching. But I have had trouble with the switch mechanics and dirty contacts in other types of Philips recorders. Hopefully testing the action of the switches will locate the fault.
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Old 30th Oct 2016, 4:34 pm   #66
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Default Re: Philips reel to reel

Not got much time to work on recorder, only few hours this morning and I'm away all week.
Not throwing in the towel just yet.
As I have checked switches before I decided to just remove the mechanism to release switch contacts but no obvious signs of the fault. Rubbed down lightly with a bit of wire wool to remove marks and replaced.
Will check each individual switch again when I have time, probably next week.
Will post how I get on.
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Old 30th Oct 2016, 5:16 pm   #67
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Default Re: Philips reel to reel

I seem to remember that the record/playback switch (the one operated by the bowden cable) switches the amplifier circuitry -- and in some machines also powers up the amplifier (independant of the main deck power swtich) so you can check the recording level by pressing the record button without starting the tape.

There's a seprate switch/swtiches on the metal deck chassis to turn the thing on and start the motor.

Is the motor running all the time (even when play is not pressed)?

How are you powering it? IIRC at least one of the power switches is between one of the battery terminals and the metal chassis. If you are powering it from a PSU with one side earthed and have earthed test gear ('scope, for example) connected, you may find you are effectively shorting out the swtich via the earth leads.
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Old 21st Nov 2016, 10:23 pm   #68
Copey84
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Default Re: Philips reel to reel

Hi all, just thought I'd finish up this post. Not able to fix recorder, think it's a job for someone more experienced with these things. Will see if my grandad wants to get someone else to have a look at it.
Thanks for all the replys have learned from them so not a complete waste of time.
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