TM 11-5805-424-15/NAVELEX 0967-220-9010/TO 31W2-2G-41
resistor, and resistor R4 is the collector load
a linear output signal to the timing output terminals.
resistor. Resistor R12 and capacitor C5 and
Diode CR1, in series with the base-emitter junction of
resistor R13 and capacitor C6 provide additional
transistor Q5, compensates for the diode characteristics
filtering of the dc power supply voltages.
of the junction. Diode CR3 limits transistor Q5 collector
voltage to +6 volts; resistors R8 and R9 provide for
(2) Output from transistor Q1 emitter is applied,
proper biasing of transistor Q5; and resistors R10 and
through a delay capacitor in the receive filter, to
R11 provide for proper biasing of transistor Q6.
impedance-matching emitter follower Q2. With
EQUALIZER switch S1 at OUT, the delay
5-18. Delay Equalization Circuits
capacitor is shorted out so no delay is
introduced into the received signal.
With
EQUALIZER switch S1 at COMP, the output.
from the collector of transistor Q1 (through
varying amounts of delay for the different input
coupling capacitor C2 and resistor R5, through
frequencies of the received fsk signals, so that the
resistor R8) is applied to transistor Q2; at the
output from the delay equalization circuits contains the
same time, the output from the emitter of
same amount of delay and, hence, no delay distortion
transistor Q1 is applied through the delay
for all frequencies in the appropriate channel received.
capacitor in the receive filter to transistor Q2.
The schematic diagram shown in figure 8-25 represents
This parallel arrangement provides a small
the circuits employed in the MX-7379/G only, employing
amount of delay over a relatively wide
a separate delay equalizer PC card (PC80034230; assy
frequency band. With EQUALIZER switch S1 at
A25A3) and switching circuit; for all other MX-73(*)/G's,
ADJ, DELAY ADJ resistor R6 is substituted for
the PC card is not used. For the MX-7380/G, MX-
fixed resistor R8, providing an adjustment of the
7383/G, and MX-7384/G, MX-7385/G, a switch selection
delay range.
circuit is provided to vary the amount of delay (A, fig. 8-
(3) When FREQ switch S2 is at B, a parallel-tuned
26). For the MX-7372/G through MX7378/G, and MX-
circuit is added, in parallel with the delay circuits
7381/G and MX-7382/G (B, fig. 8-26), no selection is
described in (1) and (2) above; this arrangement
provided; only a fixed amount of delay is available.
provides a larger amount of delay over a
Discussion of delay equalization used with the MX-
narrower frequency band.
7379/G is given in b below. Operation of the other types
is self-evident when analyzed from the overall delay
(4) The delayed signal is applied through transistor
equalization discussion given in b below.
Q2 to another delay circuit that is identical with
that described in (1), (2), and (3) above. The
delayed signal, amplified by transistor Q4, is
(1) The received input signals are applied to
applied through coupling capacitor C4 to the
paraphase amplifier Q1, which provides two
remainder of the receive circuitry. Resistor R10
outputs that are equal in frequency and
is the emitter-biasing resistor, and resistor R11
amplitude and 180 out of phase with each
is the collector load resistor for transistor Q4.
other. Capacitor C1 is the coupling capacitor,
and resistors R1 and R2 provide operating bias
for transistor Q1. Resistor R3 is the emitter load
Section IV. LOGIC ANALYSIS
TRANSMITTER DATA INPUT terminals and INPUT
5-19. Transmit Data
SELECT switch 1A1S5 (switch at DATA) to differential
amplifier DIA-1. Differential amplifier DIA-1 provides
two output signals that are 180out of phase with each
a. Input data is applied through ORDER WIRE
SEND jack 1A1J1 (no plug inserted) from the
5-17
