Vacuum tube capacitor
These might be very useful in TESLA COILS!
2-1/2"D x 6-5/8"L
Eimac vacuum capacitors are small, vacuum-dielectric units
intended principally for use as all or part of the plate
tank capacitance in radio-frequency amplifiers or
oscillators. They are also frequently used as high-voltage
coupling and by-pass capacitors at high frequencies and as
high-voltage neutralizing capacitors, when used in
conjunction with small high-voltage variable capacitors
having a small capacitance range. The use of a vacuum as a
dielectric permits the construction of a comparatively
small lightweight capacitor for a given voltage rating
and capacitance. In addition, the effects of dust and
atmospheric conditions on the capacitor are eliminated
by sealing the plates within a glass envelope.
These capacitors are manufactured in two maximum peak
voltage ratings, 32,000 and 20,000 volts, and in
capacitances of 6, 12, 25 and 50 uufd. All types have
a maximum current rating of 28 amperes. Each of the
capacitors may be operated at its full maximum voltage
rating at any frequency below that at which the RMS
current through the capacitor is 28 amperes. Above this
frequency, the R-F voltage across the capacitor must be
reduced as the frequency increases, to prevent the current
from exceeding the maximum rating.
The sum of the peak R-F and D-C voltages must not exceed
the peak voltage rating of the capacitor!
Eimac vacuum capacitors are provided with terminals which
allow the use of standard 60-ampere fuse clips for mounting.
These clips must be kept clean and must at all times make
firm and positive contact with the capacitor terminals.
Failure to maintain a low-resistance contact to the
capacitor terminals may result in excessive heating and
permanent damage to the capacitor seals.