Racal Instruments AN/TRC-207, Operation And Maintenance Instructions

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TO 31R2-2TRC207-1
4-9
4-3.2.3 Tandemed Bi-Directional Repeater.
NOTE
HHRs can be programmed with two or more channels to permit the user to access another repeater
when one is blocked from view.
Table 4-9. Tandemed BDR Recommended Frequencies
The Mode Select switch should be set to the bi-directional RETRANS position.
EQUIPMENT TRANSMIT FREQUENCY RECEIVE FREQUENCY
Base Station F
1
F
1
HHR Region 1 F
1
F
1
BDR #1, Radio A F
1
F
1
BDR #1, Radio B F
2
F
2
HHR Region 2 F
2
F
2
BDR #2, Radio A F
2
F
2
BDR #2, Radio B F
3
F
3
HHR Region 3 F
3
F
3
BDR #3, Radio A F
3
F
3
BDR #3, Radio B F
4
F
4
HHR Region 4 F
4
F
4
4-3.2.4 COMMS Mode.
Any of the above frequency set-ups can be used in COMMS mode.
4-3.2.5 Operational Techniques.
In addition to frequency separation, there are other considerations that should be made when programming the radios for
use:
a. When operating predominantly in the CLEAR mode, use CTCSS tones to reduce unwanted re-
transmitting. (Only RX tones are effective in the BDR, not TX tones.)
b. When operating predominantly in the SECURE mode, program the BDR radios for ATONES=OFF@
to speed re-transmission turnaround time.
c. When operating in the SECURE mode, wait approximately 0.5 sec. at the end of a message before
replying.
4-3.2.6 Cross-Banding.
The BDR can be used with different frequency bands on Radios A and B (e.g., Radio A in 136-174 MHz band and Radio
B in 30-88 MHz band).
4-3.2.6.1 Additional Equipment Requirements.
When using two frequency bands, separate antennas, antenna cables, antenna masts, and diplexers are required for each
band used. As noted in Chapter 1, the second antenna mast and antenna cable are not provided with the system. These
items can be borrowed from other Scope Shield systems, e.g., Tactical Repeater/BDR or Base Station, or may be
purchased separately.
4-3.2.6.2 Set-up.
If the 30-88 MHz band is used, the 30-88 MHz band radio should be inserted in the Radio B sleeve and the B/TX
connector (J2) on the BDR unit must be connected to the RF IN connector on the power supply assembly using cable W3.
The antenna cable for Radio B is connected to the ANTENNA connector on the power supply assembly and the antenna
cable for Radio A is connected directly to the A/RX connector (J3) on the BDR assembly. Figure 4-6 shows the initial
(standard) set-up for normal operation. Figure 4-7 shows how the standard set-up is changed for cross-banding operation.