The Talking Machine Forum — For All Antique Phonographs & Recordings

Over the past several months, a few generous collectors have loaned me their 7" Berliners. Most have been in nice condition but a local collector recently loaned me some, a few of which were damaged. The rim chips and needle drops have become very easy to fix, but this one is literally missing a ~¼" triangle.

Obviously I intend to repair this, here's how...
Clean and mold the disc.
Create two copies.
Clean up the broken edges on copy #1 and create a template of the missing piece.
Cut a piece out of copy #2 from either just before or after the missing piece.
Fit the piece under magnification.
Glue the piece in place.
Create a new mold and produce playable copies.

If the missing piece is ¼" and is out the outside edge then...
7" x 3.14 = 22" (circumference of disc at outside edge).
78rpm x 22" = 1,700" per minute, divide by 60 = 28" per second.
.25" divided by 28" per second = .009 seconds.
I wonder if a repeat of sound lasting only .009 seconds approximately every ¾ of a second will sound disruptive?

If it proves to be too disruptive you could always "destroy" the recorded sound in the grooves on the replacement piece so the music would just cut out instead of repeating.

A white noise area could be created by filling the void with wax and carefully etching in new grooves (under magnification). Using the area just before or after will hopefully create a better sounding repair.

Here's a little progress. The two copies came out nice and I was able to cut and fit a piece onto one of the copies.

For a first attempt, I'm pretty pleased with how well this repair went. Here's a video showing the original and the repaired copies side by side, and the repaired section being played acoustically...

https://youtu.be/JNq2rNNCxV8

That turned out surprisingly good... Berliner records are noisy anyway, so you don't really notice the flaw. The video after this one shows a repaired cylinder... is that the one you glued back together with WeldBond glue? Good save...

Yup. Weldbond works really well for repairing discs. Filling in cracks with candle wax also works well for playing electrically, or to use prior to molding and copying the disc...

HisMastersVoice wrote:If it proves to be too disruptive you could always "destroy" the recorded sound in the grooves on the replacement piece so the music would just cut out instead of repeating.

Like an 8-Track tape