Resurrecting DD diaphragms

[Chuck]

Just obtained a few genuine Edison DD diaphragms.
They all have broken links.
So far have managed to get the shellac off the back cone which exposes
the tiny nut. Unscrewed that and got the eye out.

Is there a source for NOS DD links?

Thought I'd ask first before making my own.

Chuck

[Chuck]

Well now a few days later I've managed to get all (3) of the recently
acquired Edison DD diaphragms with broken "strings" playing again.

Once you get the tiny brass nut unscrewed then the eye comes out and then
the old swaged end of the genuine braided silk link can carefully be cut
off using a small wire cutters. This then leaves the eye by itself.

From there, a new link can be made from any variety of materials.

I first tried a solid wire link. It works but it sounds harsh.
Next I tried one of the nylon strands found inside of military parachute line.
That actually sounds pretty nice!

Then I tried next two kinds of heavy carpet and button thread.
One of those kinds sounds excellent!

The loop length as near as I can tell should be between .70 and .71 inches
from the surface of the cork nearest the link loop, to the inside of the
stretched straight loop.

This puts the stylus bar nearly horizontal for an average thickness DD record.

When tying the loop, a simple overhand half-hitch can be used to tie it off.
Leaving the knot loose and then using a needle or a tiny jeweler's screwdriver in the knot
to move it around seems to work fairly well to arrive at the correct loop length
once the knot is pulled tight.

A small gauge can be made from a strip of thin cardboard such as an index card.
Mark off .71 inches from the end and hold that little gauge up against loop and knot
and then guesstimate where the knot will end up when tied tight. Might not hit it right
the first time, and if not, the knot can be untied again using a needle and high
magnification.

Once the length is good, and the knot tied tight, then the ends can be cut
off to maybe about 3/16 inch long, or so. Then, the knot and those ends can be
rotated down so they are down near the cork and the eye, not up by where
it hooks to the stylus bar. Additionally, a fine thread can be wound around
and tied to the loop, so it sort of closes off a bit near the stylus bar.
That is optional, I like it without that thread tied on there because then the loop
is free to adjust itself to equal tension on each of the two strands when playing.

The short version of this is: Save your defunct Edison original DD diaphragms
as they are made to come apart easily and a new string can be fitted and they will
play just fine once again.

Chuck

[Victrolaboy]

Thanks Chuck! I've used un waxed dental floss that I've braded for repairing diaphragm linkages but this method works much better!

[edisonphonoworks]

Braided silk is what the original material was for the link.