"N Cook" wrote in :

According to the internet a respected deck in its day.
Had to deal with the slip clutch buried in the mechanism. Photoed before
disassembly just in case. Reassembled and the 2 pinch wheels were
fighting one another. A strange pair of springs one acting against the
other for the "reverse" pinch wheel assembly. I must have put one of
these springs back with wrong anchor position. Correcting that and its
playing and FF and REW ok.
These units are called 4 head, 4 pairs of screened stereo wires going to
the head but all seem to relate half the tape. So one question is why 2
pinch wheels when there seems to be no proper "reverse" side play or
loop control function as a fixed head.
Repeat sends back to replay the same side.
The "reverse" pinchwheel seems to operate only just clear of the reverse
capstan spindle and has a strange guide that protrudes around the
pinchwheel and into the recess of the cassette - what is the function of
that protrusion and a non pinching pinch wheel ?
What do the 4 stereo heads do ?


Could it be an auto reverse deck that reverses when it hits a metal band or
transparent area of the tape, near the end of the reel?

One set of heads plays/records in one direction and the other set
plays/records in the other direction?

I seem to remember Aiwa had some like that.
My shop used to work on them in the early 70's (back when I had a shop).

The strange guide could be a 'tape tension' sensor. It may have been
disabled at some time in the past to fix some problem.

Google shows several "Aiwa F770 Three-Head Studio Quality Cassette Deck"
listings, so the chances are that it is to allow 'sound over' recording by
playing back and mixing in new audio and then recording that, after the
sound that was just played is erased.

One last possiblity, the second pinch roller could be for a second
recording speed. I seem to remember some machines that played that trick to
allow multi speed recording.






--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

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