Edison
switched to cork gaskets around 1924 as he found that cork retains
resiliency longer than rubber. (from Ron D)
Hello Bruce,
You must have only seen the later DD reproducers, from 1912 to 1924 the gaskets
are a soft natural rubber that began to harden in as little as six months. I
have seen Edison cylinder reproducers with cork gaskets, Edison still did
repairs into the 1920's.
I use a Q-Tip and a Dremel tool to polish the inside of the body where the stud
goes and the stud itself. I use synthetic oil so it will not gum up again.
The stylus bar is another critical area, many times it is gummed up and does
not move freely.
Steve
> In the first place gaskets in an Edison DD reproducer were cork not rubber.
> It is extremely important that the diaphragm is air tight. Also make sure
> that that that end of the linkage is tight as well. The brown material you
> see is burnt shellac. That was used to seal the cone to the diaphragm and
> over the ends of the tiny nut retaining the stylus cord. Using Pvc-E here
> works fine as there is no shear motion and stays pliable unlike the burnt
> shellac that is ridgid. The object again is to make it airtight. If you
> REALLY want to tighten things up, install an O ring of perfect size as the
> end of the reproducer. I tack mine on with Crazy glue. Now you have an
> airtight chamber from diaphragm to tip of horn. If you don't believe the O
> ring (air tightness) makes any difference (air tightness), take it out and
> compare the difference. Air leakage is very detrimental in an acoustic
> system.
> Bruce
> ps. remove and polish the rear weight bearing with silver polish, and
> re-oil. This is often overlooked.
>
> >
> > Assume that all old rubber gaskets need replacement. They are not there
> > to
> > make the diaphragm airtight BUT to act as vibration dampeners.
>
>
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