SONY Stereo Cassette Recorder TC-118SD - UK Vintage Radio Repair and Restoration Discussion Forum

Alf Fisher · 24th Feb 2020, 6:40 pm

Hi folks,
I have one of these cassette recorders that I haven't used for some time but on trying it out, one or two tapes play very jerkily and I put it down to the take-up hub pulling the tape too hard and what would be in a R2R machine, the felt friction drive is stuck in the high torque fast forward mode.

In the manual (see snippet attached) it mentions Torque measurements but how do you measure the torque on these things and how does the take-up friction drive work?

All offers of help welcome.

Alf

DMcMahon · 24th Feb 2020, 7:17 pm

Hello Alf,

I know how to do it on some reel to reel recorders, but no idea about cassette decks, I see the Service manual is non too helpful as regards how to measure the torques.

I vaguely knew of torque test cassettes and from a quick web search I see that Sony do one, a TW-2131, would be worthwhile you reading up on that for a start.

David

mitajohn · 24th Feb 2020, 9:52 pm

You request something as in the pic.

Alf Fisher · 25th Feb 2020, 12:07 am

Hi David and John,
Thank you for your suggestions.

Having done a quick search, it appears that these things are no longer available unless you know differently. There was a supplier on eBay called patshuai_2 but doesn't appear to be trading now. I suppose there might be someone on here willing to lend me one or there could be a pre-owned one on eBay.

I'm pretty much convinced that the take up torque on playback is way too much and is dragging the tape through at a variable rate. A quick crude test by attempting to grasp the hub as it is spinning and compare it with other decks if I had another one! Also it will depend on the capstan pressure which is another setting that I need to look at.

Onward and upward as they say!
Cheers,
Alf

ben · 25th Feb 2020, 1:11 am

My quick test for excess take up torque is to run a cassette with the cover off and momentarily jam a pencil into the take up spool to stop or slow it and see if things return to normal.

Excess take up torque can usually be most clearly seen at the start of a thin tape like c90, if the tape is wrinkled at the pinch roller then try the test above to further confirm things.

Some decks have a spring under the take up spindle which regulates the pressure onto a felt slip clutch. Others like Philips and ISTR a Sankyo mech that have an adjustable 'ratchet' on the TU spindle.

In this case, check that hardened grease is not preventing the FFWD idler from disengaging.

mitajohn · 26th Feb 2020, 12:13 pm

On ebay you check for this: https://www.ebay.co.uk/itm/Sony-Cass...sAAOSw1UpeVOdA

but it costs!

Alf Fisher · 28th Feb 2020, 7:07 pm

Thanks John but not at that price!!!

Thank you to Ben - I'll try the pencil trick for a start and will probably have to take it to pieces again.

Chhers,
Alf

24th Feb 2020, 6:40 pm	#1
Alf Fisher Hexode Join Date: Sep 2005 Location: Potton, Bedfordshire, UK. Posts: 293	SONY Stereo Cassette Recorder TC-118SD Hi folks, I have one of these cassette recorders that I haven't used for some time but on trying it out, one or two tapes play very jerkily and I put it down to the take-up hub pulling the tape too hard and what would be in a R2R machine, the felt friction drive is stuck in the high torque fast forward mode. In the manual (see snippet attached) it mentions Torque measurements but how do you measure the torque on these things and how does the take-up friction drive work? All offers of help welcome. Alf Attached Thumbnails

24th Feb 2020, 7:17 pm	#2
DMcMahon Dekatron Join Date: Apr 2019 Location: Worthing, West Sussex, UK. Posts: 6,602	Re: SONY Stereo Cassette Recorder TC-118SD Hello Alf, I know how to do it on some reel to reel recorders, but no idea about cassette decks, I see the Service manual is non too helpful as regards how to measure the torques. I vaguely knew of torque test cassettes and from a quick web search I see that Sony do one, a TW-2131, would be worthwhile you reading up on that for a start. David

24th Feb 2020, 9:52 pm	#3
mitajohn Pentode Join Date: Sep 2005 Location: Athens, Greece Posts: 197	Re: SONY Stereo Cassette Recorder TC-118SD You request something as in the pic. Attached Thumbnails __________________ Regards, John

25th Feb 2020, 12:07 am	#4
Alf Fisher Hexode Join Date: Sep 2005 Location: Potton, Bedfordshire, UK. Posts: 293	Re: SONY Stereo Cassette Recorder TC-118SD Hi David and John, Thank you for your suggestions. Having done a quick search, it appears that these things are no longer available unless you know differently. There was a supplier on eBay called patshuai_2 but doesn't appear to be trading now. I suppose there might be someone on here willing to lend me one or there could be a pre-owned one on eBay. I'm pretty much convinced that the take up torque on playback is way too much and is dragging the tape through at a variable rate. A quick crude test by attempting to grasp the hub as it is spinning and compare it with other decks if I had another one! Also it will depend on the capstan pressure which is another setting that I need to look at. Onward and upward as they say! Cheers, Alf

25th Feb 2020, 1:11 am	#5
ben Dekatron Join Date: Aug 2006 Location: Madrid, Spain / Wirral, UK Posts: 7,498	Re: SONY Stereo Cassette Recorder TC-118SD My quick test for excess take up torque is to run a cassette with the cover off and momentarily jam a pencil into the take up spool to stop or slow it and see if things return to normal. Excess take up torque can usually be most clearly seen at the start of a thin tape like c90, if the tape is wrinkled at the pinch roller then try the test above to further confirm things. Some decks have a spring under the take up spindle which regulates the pressure onto a felt slip clutch. Others like Philips and ISTR a Sankyo mech that have an adjustable 'ratchet' on the TU spindle. In this case, check that hardened grease is not preventing the FFWD idler from disengaging. __________________ Regards, Ben.

26th Feb 2020, 12:13 pm	#6
mitajohn Pentode Join Date: Sep 2005 Location: Athens, Greece Posts: 197	Re: SONY Stereo Cassette Recorder TC-118SD On ebay you check for this: https://www.ebay.co.uk/itm/Sony-Cass...sAAOSw1UpeVOdA but it costs! __________________ Regards, John

28th Feb 2020, 7:07 pm	#7
Alf Fisher Hexode Join Date: Sep 2005 Location: Potton, Bedfordshire, UK. Posts: 293	Re: SONY Stereo Cassette Recorder TC-118SD Thanks John but not at that price!!! Thank you to Ben - I'll try the pencil trick for a start and will probably have to take it to pieces again. Chhers, Alf