Dynascan B&K 667 Kullanım Kılavuzu - Sayfa 8
Test Ekipmanları Dynascan B&K 667 için çevrimiçi göz atın veya pdf Kullanım Kılavuzu indirin. Dynascan B&K 667 12 sayfaları. Solid state tube tester
Sayfayı Yazdırsuppressor
grid
also has
two
connections
(2, 7).
On
a normal
tube
tester
without
multiple
lockout
switches,
the
SHORTS
lamp
would
glow
in
positions 2, 3, 6 and 7 and
the chart would
have
to say "normally
shows
short in positions 2, 3, 6, 7".
By using the lockout switch we open pins 6,
7 and 8. A short in the tube between screen grid and suppressor will now
show up in positions 2 and 3 of the Selector switch.
Without the multiple
lockouts—this short would go undetected!
Through the use of this lockout technique we know that any time the
SHORTS
lamp glows, there is definitely a SHORTS
defect in the tube.
FIGURE
2.
Checking for shorts between
Suppressor
Grid
and all other elements,
Pins
6,
7,
and
8
are
locked
out
Testing Tubes for Quality
The test for the quality of a tube is a comprehensive
cathode
emission
test. It is important to test the tube under a load condition which will in-
sure that a tube passing this test will have adequate emission to properly
operate in a circuit.
One of a number of different voltage-load resistor com-
binations is selected to offer the most appropriate test for a particular tube
type.
The resultant cathode current is measured by a
sensitive solid state
amplifier and a quantitative reading is obtained on the meter
(See Figure
3). The meter is divided into three sections:
Bad-Questionable-Good,
al-
lowing a fast and accurate determination of the tube's quality.
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