RCA 100-A Speaker
Corporation of America Year of Manufacture: 1927
This was an eBay purchase in October of 2006. This
was purchased with the intention of pairing it up with my Radiola 18. Restoration began in the
summer of 2009. At a first glance, I thought the original paint and
grille cloth were trashed. Asking a few questions via the Antique Radio
Forums, original thread, I was able to
find out what the correct replacement paint colors were. The
electronics would prove to be rather easy to restore. Below: An original advertisement from 1927.
Upon disassembly, the speaker cone and frame were
found to be in relatively good shape, with very little rust present.
After a cleaning, a new cord was installed, a two conductor brown cloth
covered type to replace a black cord someone had installed long ago.
Hooking up the speaker to an audio device, I am able to get decent
sound and volume, not too bad for just a cleaning. The circuit on this
thing consists of a black cylinder shaped object mounted to the speaker
that serves as some sort of filter. As my speaker seemed to be working
ok, I left this alone.
Case and Grille Cloth Restoration
Before attempting anything drastic like
stripping/repainting, I wanted to extinguish all of my other options
first. The case looked great after cleaning it with Armour All Orange
cleaning wipes. The case was then coated with clear
gloss lacquer. In between coats it was sanded using 800 grit wet/dry
paper. This way I was able to preserve the original paint and give it a
nice gloss finish. This speaker
is constructed using a pot-metal type of metal which is prone to
cracking and warping. Luckily my speaker has no signs of this type of
While an exact reproduction of the grille cloth is
available, I wanted to test out a procedure recommended by a fellow
radio restorer. The old cloth was filthy, so it was carefully removed
and laid out on a piece of flat glass. It was then soaked with 409
household cleaner. The cleaner was tested beforehand on a small section
insure that it wouldn't ruin the color. Once soaked with the cleaner,
the cloth was patted down with shop rags. It was then thoroughly rinsed
with water until there were no more traces of the cleaner. The grille
cloth was then placed in front of a dehumidifier, still on the glass,
and was dried over a two day period. The final results really improved
the look of the cloth. As you can see in the above two photos, this
cloth looks very different depending on the angle you are viewing it. Below: The speaker before restoration.