[Amps] Case isolation of oiled-paper capacitors

[Harold B. Mandel]

Sr. Vilaseca,

In the ALPHA 77-series of amplifiers the oil-filled filter capacitors
were mounted on a piece of foam rubber material, but had metal clamps
securing their fastening, which clamps were grounded to the chassis of
the amplifier.

In addition, the oil-filled capacitors had a small sheet of
silicone-rubber
in between the clamp and the capacitor body, making for an isolated
capacitor in the amplifier housing.

In building the 3.0 ampere outboard supply for the HF amplifier
project now underway here, the two oil-filled capacitors were mounted
on double layers of 7.5KV-rated Electroshield insulation with 
the same material cushioning them against contacting the sides of the
power supply
cabinets. Instead of clamps securing their fastening, a dab of RTV
silicone on the sides plus a hold-down plate of red fiberglass 
"Rhyolite" 5mm. material (used in powerplant framework construction)
secure the capacitors against movement.

If the two terminals on the capacitor both sport robust insulation
it would seem reasonable to isolate the case as best as possible to 
reduce the tendency for the case to be a current-carrying component
of the capacitor.

Respectfully,

Hal Mandel
KA1XO