Simpson 1000 - Page 7

GENERAL DESCRIPTION
dicate if there is a leakage path either from the cathode to
the filament or from the cathode to the plate.
In a pentode, three tests are required; the cathode, screen
grid, and plate are each separated (one at a time) from the
rest of the elements, and any leakage in either direction
from any of these elements will show on the ohmmeter. The
resistance value markings on the OHMS scale are black for
values above 250K ohms, and are red for 250K and less.
This shows any resistance which is below the defined
minimum desired value (tube standards) in the red portion
of the ohmmeter scale.
A dead short will show full scale pointer deflection, or
zero ohms. The circuit which is used to check shorts and
leakage allows you to determine which elements are in-
volved in the short and intelligently evaluate the useability
or limitations of use of the tube for a circuit application.
PIN SOCKET
Pilot lamps and Christmas tree lamps can be tested quickly
in the center of the large 7-pin socket. Insert either screw
base or bayonet base lamps in this socket to determine
whether they will light. Set the filament switch at a po-
sition which will produce the proper voltage for the lamp
under test; set toggle A at position O, and toggle G at 1.
Press the lamp base into the test socket to see whether
it will light.
FUSE
A fuse is mounted in the front panel and connected in
series with the primary of the power transformer. If there is
any current overload condition which develops in the tube
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