Thorn DC432 and DC43 tape decks - rewind problem

[dazzlevision]

After a full refurbishment, I’m in the process of testing a Thorn group stereo tape recorder fitted with the DC432 Schedule B tape deck (which is very similar to the DC43 mono deck).

I’d been making test recordings on all three speeds, but when I went to rewind the recording made at “one and seven eighths” inches per second, with the 7” supply reel full of tape, the motor stalled (it was fine on the two higher speeds).

Now this deck gets drive to the turntables in fast forward and rewind, by coupling a brass pully on the motor shaft to the relevant turntable, via rubber idler wheels. In the case of rewind, two idler wheels are used.

So, I firstly checked they were free to spin and cleaned the driving surfaces, but this made no difference.

I then noticed that, at the slowest speed, the metal rod that is part of the speed change system and which projects through the deck plate right under the idler wheel nearest the supply turntable, was actually fouling it – but only at the slowest speed, when it projects the most.

Now accessing the speed change mechanism on this deck involves a lot of dismantling on the underside of the deck, so I applied a file to the top of the rod and shortened it by a millimetre or so. This did the trick.

I’ve never encountered this on a DC43 or DC432 deck before, but I shall examine my other Thorn recorders to see if they have this problem.

Of course, it might be that another plastic part (the white parts in the photos) of the speed change mechanism has worn over the years, but my “fix” is a lot easier to implement!

[dazzlevision]

Some more photos.