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Ross Herbert Ross Herbert is offline
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Default Repair of Crystal Phono Cartridges ?

On Sun, 5 Nov 2006 08:08:33 -0800, "Blake"
wrote:


"Ross Herbert" wrote in message
.. .
It must be a pretty big cartridge if it will take a 15mm diameter
ceramic disc. In my experience, the crystal/ceramic element in a phono
is quite small so I think you are not going to have any success in
repairing it. The elastic suspension carrier for the element might
have deteriorated as well so you will probably find this a problem.

Not to put too fine a point on it, why not just buy a new ceramic
cartridge and save all the hassle? Though looking at some of the
prices here http://www.turntableneedles.com/brow...cts/Index.html
you might not like it.



Thanks for the reply.

Actually, I've already examined the failed cartridge. The old crystal seems
to be a slab about 15mm long and 10mm wide, fitting into a space 15mm wide
and 25mm long inside the cartridge shell. I thought I might be able to grind
the sides of that circular 15mm barrium titanate piezo on a belt sander to
adjust the fit. Or if it shatters on grinding, find a slightly smaller one.

My old crystal was clamped into the cartridge by two rubber blocks, one
glued to the top shell and the other to the bottom. The gap between measures
about the same as the crystal thickness. Are these what you mean by the
elastic suspension carrier? There was also a thin, crumbly black coating on
the white crumbly crystal. I took this black coating for a conductive
electrode, but if this is an elastic suspension, then I might need to
understand its function better. Maybe the barrium titanite can go without a
coating. Or I could dip it in the kind of liquid rubber they sell for
coating tool handles. This point bears some more consideration.

As for buying a new cartridge, well . . . You guessed right about my
willingness to invest cash in the project. This phono isn't a fine antique,
and would probably not fetch more that $25 after I finish the repairs. But
more importantly, I wouldn't learn anything or have any fun by hiring a
specialist to do the job for me. And we're all in this for the fun of it,
aren't we?



I can well understand your desire to achieve satisfaction from fixing
something for little or no cost, and I certainly wouldn't try to stop
anyone from "having a go".

The last time I opened up a crystal phono cartridge was back in the
50's so I don't remember all the details. I am fairly sure the
Goldring cartridge I pulled apart didn't have a slab as big as in your
unit. I do remember that the crystal was very easily damaged. The
crystal element was superseded by a ceramic element in the 60's and
these were much more robust.

You might be lucky enough - with great care - to whittle down one of
the elements you are looking at as a replacement and then succeed in
mounting it along with its soldered connections so that it produces an
output. However, I don't think you would be pleased with the sound it
produced if any. Give it ago and see what happens. You can only try
and if it doesn't succeed then it hasn't cost anything except a lot of
labour, and that can be considered free in your case I suspect.

I once tried a similar resurrection project with a 1930's model
telephone right down to rewinding the induction coil since I couldn't
find a suitable replacement. While it did work to some extent it was a
failure in my estimation. In your case however, you are still able to
get new replacement parts for your project, so if I were you and I
really wanted to get it working as near to original as possible, I
would tend to opt for a new cartridge. That way you would get the
desired result and satisfaction at the same time.

Good luck.