The Talking Machine Forum — For All Antique Phonographs & Recordings

Hi all,

I'm trying to identify this recorder. Its made out of pot metal and its cast in only one piece.

What strikes me is that it has no lip at all in the perimeter so I don't know how I will be able to install the diaphragm and cutting stylus. It only has the remains of a wax ring on it. If anybody has pictures of another one complete or something similar I would greatly appreciate them.

Thank you in advance,

Pedro Martínez

You can make some suitable spacers and gaskets
out of various thicknesses of cardboard.
Then boil the cardboard rings in melted beeswax,
let it cool, then scrape off the excess.

Various thicknesses can be used. I'd start out
by finding some cardboard in thicknesses such as
.015, .020, .025 inch, maybe even as thick as .030 inch.
Cut the rings so they have a difference of inner and
outer diameters of about .100 to .120 inches.

Assuming it is starting from a good flat metal
surface, I'd first try it with the .020 or the .025
inch thickness for the spacer that holds the diaphragm
away from the metal, but still very close to it, to form
the air chamber. Then the outside surface of the
diaphragm can be sealed using one of the thinner rings.

After it's all waxed together using beeswax, then make
sure that the entire outside diameter is sealed air
tight.

Then glue the cutter holder with the cutter mounted
in it, to the diaphragm and start testing it.

Be prepared to put this together and take it apart
several times before getting it to work
the way you want it to work.

I'd leave some exposed metal on the outside diameter
in order to provide a surface to seal to.

Thank you very much for your explanation. It makes perfect sense now. I will rebuild it in the next weeks and share my results.

Best regards,

Pedro Martínez

Pedro,

That looks like a fun project! The small
tools needed to work the beeswax can be made from
small narrow strips of thin sheet metal.

These thin narrow strips can be rounded on the ends
using small files, and made smooth.

Being thin and flexible, they can be bent into
many different shapes to aid in spreading out and
working the soft beeswax while it is still warm.

I heat the beeswax in a spoon held over an alcohol
lamp flame.
That is how I boil the gaskets and afterwards have a supply of warm and soft beeswax
to form into small rolls. Roll those in your fingers
until they become long and thin, and then pack them
where they are needed like little ropes. Then smooth
them using the small sheet metal tools. A heated
tool applied to a cool wax area will melt it locally
and form it however you want it.