Electro-Metrics EM-2115, Instruction Manual

Page: 86 / 278

EM-2115 4.0 SERVICE, MAINTENANCE, CALIBRATION
(EM2115S4-18)
3) Middle IF Bandwidth: 10 kHz, specification limit: 10 kHz ±10%. IF center fre-
quency adjustment: L3004.
4) Narrowest IF Bandwidth: 1 kHz, specification limit: 1 kHz ±10%.
l. Set the Frequency Range to 20-45 MHz (11) and repeat Steps e thru j for the 8.7
MHz IF channel, except for the following:
1) Apply a 8.700 MHz signal at an input level of 75 dB(µV) to A3J1.
2) Widest IF Bandwidth: 1 MHz, specification limit: 1 MHz ±10%.
3) Middle IF Bandwidth: 100 kHz, specification limit: 100 kHz ±10%. IF center
frequency adjustment: L4004.
4) Narrowest IF Bandwidth: 10 kHz, specification limit: 10 kHz ±10%.
4.4.5.2 IF Amplifier Gain Check/Adjustment
a. Set the front panel controls as follows:
DETECTOR ...................................................PEAK
BANDWIDTH ...............................................Wideband position of the frequency
range selected.
ATTENUATION ...........................................0 dB
FREQUENCY RANGE .................................0.009-0.035 MHz.
FREQUENCY DISPLAY ..............................0.022 MHz
b. Place the Detector Board (A8) onto the 36 pin double-sided extension board and
connect a Digital Voltmeter to A8-16.
c. Set the Bandwidth for 9/10 kHz (Wideband IF Bandwidth of the 175 kHz IF
channel) and set the signal generator output level to +65 dB(µV) at 175.00 kHz.
d. The Digital Voltmeter monitoring the voltage on A8-16 should indicate +1.50
VDC ±0.023 VDC.
e. Set the Bandwidth to 1 kHz (Middle IF Bandwidth position of the 175 kHz IF
channel). Verify that the center frequency of the 1 kHz IF Bandwidth is identical
to the 9/10 kHz IF Bandwidth. The Digital Voltmeter should indicate +1.50
±0.023 VDC.
f. Set the Bandwidth to 200 Hz (Narrow IF Bandwidth position of the 175 kHz IF
channel). Verify that the signal is peaked for maximum. The Digital Voltmeter