cardboard tube and one of
your new components.
Axial lead film capacitors
work best here, but you
can bend the leads of a
radial component, and
that's just fine. Slide the
new cap into the tube,
center it, and use a small
dab from the heat gun to
hold the part in position
inside. Let the glue harden
for a few seconds, then
take your brown or beige
polymer clay and push it
into the sides, filling up the
empty space and forming
the end plugs of the
capacitor.
Once you've filled in the ends,
take the newly re-stuffed capacitor
and give it a quick dip once or twice
in your molten bee's wax (Photo 6).
Let it dry for a few seconds and set
aside.
You've re-stuffed a capacitor!
Repeat for the rest of the caps in
your radio, and you'll have a new set
(Photo 7).
Re-stuffing the electrolytic
capacitors is a little harder.
Electrolytic capacitors are commonly
found in cans above the chassis due
to their size back in the day. Some
people remove these cans, drill the
case open just above where it
mounts, extract the guts, and bundle
up new electrolytic capacitors inside
an insulator before gluing and taping
the assembly back together. It's
messy and frankly, in my opinion, it's
tough to make it look good. Dealing
with those hassles isn't an issue for
the DeWald, though. It's missing its
can capacitor, and there's a set of
modern electrolytics instead.
Here, I'm going to fake it a little
bit. The radio only needs to really
look period correct at first glance,
and modern electrolytics are so
much smaller than they used to be. I
found a slightly larger shell of an old
paper capacitor which will fit a pair
of 22 µf 450V electrolytic capacitors
inside its diameter (back to back),
with just a tiny bit of room to spare.
For this one, I gutted the old
capacitor, then slid both electrolytics
in. Now, there's a paper capacitor
with two leads coming out of each
end. It's not quite historically
accurate, but it looks good at first
glance (Photo 8).
Down to Business
Armed with a new set of
“vintage” capacitors, it's time to swap
out the components. Just cut and
replace! Try and get the new
capacitors as physically close to the
position of the old capacitors as
possible. Lead dress — the
arrangement of the
components and wires — is
a big deal in radios this old,
and component positions
which differ radically from
when it was built can cause
problems like interference,
feedback, and squealing
when it's powered up
(Photo 9).
Sometimes radios like
this are built in layers, and
you have to remove some
top components to get to
the ones below them. I use
an alligator clip jumper
wire on each end of the
component I've temporarily
bent out of the way to
make sure I don't lose my place while
working on the deeper layers. Then, I
come back and replace the jumper
placeholder. I did end up extending
some leads for the new "electrolytic"
capacitors I installed, using leftover
cloth covered wiring from another
project to preserve the appearance
(Photo 10).
While in there, I spot-checked
the resistors in the radio. Resistors
were made of a molded carbon
compound back then, and as they
age and absorb moisture from the
June 2015 51
Photo 6. Dipping a re-stuffed capacitor in new wax
to seal it.
Photo 7. The assorted capacitors for this De Wald radio.
Photo 8. Both electrolytic capacitors stuffed into one tube.