TM 11-5985-355-13
9146/GRC connector J2 to the rotary switch(S1). Plus
current path from Q1 to the latching solenoid. Without a
25 volts dc is applied to terminal K of connector J2
current path to the solenoid, switch S1 remains in
whenever the equipment is on. When the BAND switch
position 2. In that position capacitor C23 is connected
in the receiver-transmitter is in position A, 25 volts dc is
between ground and the outer conductor, and reactance
applied to terminal A of connector J2 or in position B to
elements connected to the inner conductor are shown in
terminal B. The switching action of the band switch
the chart (a above).
increases the number of selectable reactance networks
from 5 to 10. The control voltage from S309 or S:359
changed to 33-37 MHz (band segment 2) and then to 30-
feeds through switch S1-B rear (band A) or S1-B front
33 MHz (band segment 1), the sequence is the same as
(band B). Plus 25 volts on terminal K of J2 is applied
explained above, except that voltage is applies to J2-E
through switch S1-A to the rotary latching solenoid (part
and J2-D, respectively, the switch positions are 3 and 4,
and the reactance elements are as shown in chart ((u
of switch S1). Diode CR1 provides arc suppression for
switch S1-A and the rotary latching solenoid, thyristor Q1
above).
is turned offor0 on whether or not it is gated by a control
(4) Positions 5, 6, and 7. If the 70.5-80 MHz
voltage.
range (band segment 10) is selected next, control
d. RF Path. Rf energy is applied through a coaxial
voltage will be applied to J2-H, and J2-B, as well as J2-
cable to connector J1, switch S1, matching networks,
K. Latching voltage for the latching solenoid is provided
shunt reactors, cable choke L16, connector J:3 and to
through J2-H, contact no.
9 to S1-B rear, the
the whip antenna.
interconnection from S1-B rear to S1-B front wafer,
c. Functioning of Rotary Latching Solenoid. The
contact no. 6 on S1-B front to resistor R1, Q1 and S1-A.
rotary latching solenoid (part of S1) advances switch S1
Since control voltage exists at J2-B, Band 2 is selected;
in steps. At each step, the solenoid connects switches
therefore an alternate path contacts No. 8 and No. 6 of
S1-C, S1-D and S1-E to one of the shunt reactance
S1-B front to resistor R1 is completed. Switch S1 rotates
networks (except where none is necessary ) and opens
to position 5. Although the connection a from contact
switch S1-A. After each step, switch S1-A closes, and if
No. 8 of S1-B front has opened, contact No. 8 of S1-B
power is still available at switch S1-B front or rear, it will
rear remains connected and the latching step will step,
step again. During the last step, a normally operating
rotating switch S1 to position 6. The switch remains at
thyristor Q1 cuts off removing ground from the rotary
rest in this position since contact No. 8 is no longer
latching solenoid and steps the stepping action. When
connected to S1-B rear wafer, and coil L13 is connected
the stepping action stops, a reactance network (except
to the outer connector. Capacitor C5 is connected
where none is required) remains connected to the outer
between ground and the inner connector while capacitor
conductor, and matching networks to the inner
C4 is connected in series with the rf input line. If the
conductor.
frequency is then changed to 65-70.5 MHz (band
f. Switch Positions..
segment 9), control voltage is switched from J2-H to J2-
(1) Position, 1. If the associated receiver-
G, and remains applied to J2-B and J2-K. One patch for
latching solenoid voltage exists through J2-G, contact
transmitter is set to 42-47.5 MHz (band segment 4),
No. 10 of S1-B rear, interconnection from S1-B rear to
switch S1 assumes switch position 1. Control voltage
S1-B front wafer, contact no. 6 of S1-B front. The switch
(+25 volts dc) is connected to terminals K, A and G of J2,
rotates to position 7 and, since the current path to the
but not to terminal B. In this position, coil L8 and
solenoid has opened, remains there.
Coil L14 is
capacitor C18 are connected to the inner conductor of
connected to the outer conductor. Capacitor C3 is
the transmission line and capacitor C24 is connected
connected between ground and the inner connector,
between ground and the outer connector.
If the
while capacitor C2 is connected in series with the rf input
frequency setting of the receiver-transmitter is changed
line.
to 37-42 MHz range (band segment 3), control voltage is
switched from J2-G to J2-F, remains applied to A and K,
is changed consecutively to 60-65 MHz (band segment
but not to terminal B. There is a closed path for current
8), 56-60 MHz (band segment 7), 53-56 MHz (band
through Q1, latching solenoid S1, and normally closed
segment 6), the sequence is the same
switch S1-A. The latching solenoid is energized and
rotates the switch to position 2 (37-42 MIHz range) as
explained in e above.
(2) Position 2. In position 2, the S1-B front
and S1-B rear rotors have moved one position clockwise;
neither is connected to its no. 11 contact. Since no
voltage is applied to contact No. 6, there cannot be a
5-2
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