MIL-DTL-38449D
a. Replace the system simulator with a 100K-ohm fixed carbon resistor connected, in
parallel with a vacuum tube voltmeter (VTVM), or equivalent, between pins 6 and 12.
b. An audio oscillator operating at 1 kHz shall be connected across pins 9 and 12, and its
output set to less than 25 millivolts rms (-30 dBm).
c. With pin 11 grounded to pin 2, oscillator output shall be slowly increased until the
VTVM provides an indication.
d. The VTVM shall be disconnected from pins 6 and 2 and connected across the
oscillator. The indicated voltage level shall be recorded as the attack level (0.33V rms, ±3 dB;
-7.4 dBm, ±3 dB).
e. Oscillator output shall be set to 0.7V rms (-1 dBm,1,000 Hz), and the output voltage
across pins 6 and 2 (0.5 lV rms, .3 dB; -3.6 dBm, ±3 dB) shall be checked. This shall be
repeated at frequencies of 400 Hz and 3,000 Hz. The output across pins 6 and 2 shall be within 3
dB of the 1,000 Hz level.
f. Steps a through e shall be repeated with pin 11 connected to 28V dc except that:
(1) Attack level shall be 0.11V rms ±3 dB (-16.9 dBm, ±3 dB).
(2) Oscillator output shall be set to 0.25V rms (-10 dBm).
(3) Output noted across pins 6 and 2 shall be 0.575V rms, ±3 dB
(-2.6 dBm, ±3 dB).
g. With pin 11 connected to 28V dc, oscillator output shall be increased to 4V rms.
Using an oscilloscope the peak output across pins 6 and 2 shall be checked and shall be less than
3.5V.
4.4.6.3.2 Receive gain. The unit shall be checked as follows:
a. Pin 11 shall be connected to 28V dc, and a 150-ohm fixed carbon resistor shall be
connected across pins 9 and 12.
b. An audio oscillator operating at 1 kHz shall be connected to a system simulator and
the voltage between pins 6 and 2 set to 0.05V rms (-24 dBm).
c. The voltage at pins 9 and 12 (0.26V rms, ±3 dB; -9.5 dBm, ±3 dB) shall be measured.
d. Without changing the voltage level output of the oscillator, repeat step c at output
frequencies of 400 Hz and 3,000 Hz from the oscillator.
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