Tektronix 502 series, Instruction Manual

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ACCESSORIES
O p e ra tio n a l Accessories
TYPE 123 PREAMPLIFIER
Compact
3 % " high, 1
V2 "
wide, 2 - 3 /1 6 " deep.
W eighs only 10 ounces.
V o lta g e Gain
Accurately set at 100 times.
Passband
Within 2 % from 15 cycles to
6
kc.
Within 3 db from 3 cycles to 25 kc.
M axim um Input Signal
0 . 1
v peak-to-peak.
Hum-Free Low-Level Am plification
Powered by miniature batteries.
GENERAL DESCRIPTION
The Tektronix Type 123 Preamplifier is a compact,
light-weight, battery-operated amplifier for use in appli­
cations where a gain of
1 0 0
without additional hum sig­
nal is desired. Passband is 3 cycles to 25 kc. Etched
wiring, miniature tubes and small batteries are combined
in a unit about the size of
2
king-size cigarette pack­
ages. W here reduced high-frequency response is per­
missible, ground-loop hum pickup can be virtually elim­
inated by mounting the Type 123 close to the circuit
under observation. Coaxial connectors permit the Type
123 to be connected directly to an oscilloscope or other
instrument, and at reduced high-frequency response, in
a connecting cable, or even for use as a probe. Shock-
mounted chassis reduces the effects of microphonics, shift,
and drift.
Applications of the Type 1 23 are confined to the audio
range; for example, observing hum levels, transducer pre­
amplifier, and other low-level applications where a gain
of
1 0 0
is desired.
CHARACTERISTICS
V o ltag e Gain
— Gain is 100, adjustable with screw­
driver calibration control.
Passband
— Within 3 db from 3 cycles to 25 kc.
Within 2 % from 15 cycles to
6
kc.
B attery Powered — A small mercury cell supplies the
filament voltage and a miniature 30 v battery is the
source of plate voltage. Life of the mercury cell is ap­
proximately 100 hours. Low plate current, 75 microamps,
assures plate-supply battery life of more than
1 0 0
hours.
Noise Level
— The maximum noise level with the in­
put grounded is less than 7.5 microvolts, rms.
Output Signal Level
— DC level of output is approxi­
mately -f 15 v.
M axim um Input Signal
— Maximum input signal for
linear amplification is
0 . 1
v, peak-to-peak.
Input Impedance — 10 megohms.
Effective O utput Impedance
— 31 kilohms.
Vacuum Tube Complem ent — Two Type 512AX
sub-miniature filament-type pentodes.
M ECHANICAL SPECIFICATIONS
Construction— Aluminum-alloy cover and etched-wir-
ing chassis.
Finish— Photo-etched anodized front panel.
Dimensions— 3 Vs" high, 4 % " including coaxial con­
nector;
1 V i
" wide; 2 - 3 /1 6 " deep, 3
%
" including coaxial
connector.
W eight— 10 ounces.
Power Requirements— One 1.345 v mercury cell and
one 30 v miniature battery, included with the instrument.
P r i c e ...............................................................................$ 5 0
Includes: 1— Mercury cell
1— B battery
T e k t r o n i x , Inc, A -l