On 2010-09-26, Ignoramus10035 wrote:
On 2010-09-26, DoN. Nichols wrote:
On 2010-09-25, Ignoramus10035 wrote:
Today...

Bought a

[ ... ]

Super old phonograph with some kids music included for $15. This might
not work and I may need to throw it out.

Depends on what you mean by "super old".

If it is old enough, the most likely failure will be the spring which
drives the turntable. (Wind up style.) The other thing is you will
need some consumables (needles -- cactus needles work nicely -- steel
ones have to be replaced more often or they start to grind away the
music from the grooves. Of course this is purely deadly to stereo
recordings. :-) But the playback is purely acoustic -- no electronics or
electrics. Be warned -- the spring is a flat clock spring type, but 1"
wide and thick -- a killer if it gets loose. Usually, the failure is
where it hooks to either the center shaft or the outer cage, and it is
possible to make a new hole at the cost of some play time by shortening
the spring.


DoN, this is a wind up phonograph with a needle. The problem is that
the arm holding the needle seems to be a little loose and not balanced
by any kind of a spring etc. It feels wrong. I would expect it to come
down on the disk gently and to be relatively stable. I may post some
pictures and a video.

But there *is* a mechanism to lower the needle gently onto the
disk. It is *you*. Those things had a rather extreme stylus force
compared to recent ones. A good recent one can operate at as little as
one gram of stylus force -- or perhaps even as little as 3/4 gram.

Those old windups had stylus forces measured more in *ounces*.
This is why you need to replace steel needles very frequently, because
the shellac (not vinyl in those days) rapidly wore down to chisels.

The preferred needle was a cactus needle -- soft enough so it
would not kill the record quickly. (The tradeoff was you lost some of
the highs, but in those days, there was not as much of an interest in
fidelity anyway. :-)

You *really* don't want to use this on any vinyl record -- the
forces are too high. (If the record bends a little in your hands, it is
vinyl -- if it is stiff, it is shellac, and will break if you add a
little more force -- or look at it wrong. :-)

So -- what you have is the way it was designed. The stylus
force was needed to mechanically couple the needle to the diaphragm in
the end of the arm to produce sound. The rest of the "amplification"
was from a long tapered path from the diaphragm through the arm down
through the board and out eventually to a grille. No volume control --
on or off. (Unless there are sliding panels in front of the grille. :-)

Enjoy,
DoN.

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