UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

Mooly · 3rd May 2021, 2:45 pm

I don't know either of those specs... just saying that first.

If the playback speed is varying as you say at 4Hz then I would look at such things as any auxiliary drives of the main capstan flywheel such as take up clutches for the take up spool and so on.

Don't discount something like a problem with back tension. Try unspooling a few seconds of tape from the supply spool so that the spool doesn't turn for a moment or two and see if that alters anything.

Also see if the take up torque is smooth and constant and not 'grabby'

Make sure any brake pads are not binding. Pinch roller in good condition and not showing any flat spots?

3rd May 2021, 2:45 pm	#2
Mooly Octode Join Date: May 2011 Location: Lancashire, UK. Posts: 1,351	Re: Cassette capstan speed. I don't know either of those specs... just saying that first. If the playback speed is varying as you say at 4Hz then I would look at such things as any auxiliary drives of the main capstan flywheel such as take up clutches for the take up spool and so on. Don't discount something like a problem with back tension. Try unspooling a few seconds of tape from the supply spool so that the spool doesn't turn for a moment or two and see if that alters anything. Also see if the take up torque is smooth and constant and not 'grabby' Make sure any brake pads are not binding. Pinch roller in good condition and not showing any flat spots?