TB 9-6625-1932-24
NOTE
Allow equipment to warm-up for one hour for first cardinal test
point frequency only.
(29) Establish a 0.00 dB reference on receiver system at test frequency.
NOTE
Ensure receiver system is in measurement mode.
(30) Disconnect fixed short from equipment setup (fig. 4).
(31) Zero power meter No. 1 and connect TI to directional coupler No. 1 (No. 2), point
A (fig. 4). Record receiver system indication as return loss.
(32) Disconnect TI from directional coupler No. 1 (No. 2) and connect fixed short to
directional coupler No. 1 (No. 2) point A (fig. 4).
(33) Repeat technique of (29) through (32) above 2 more times and average values.
(34) Determine VSWR using Appendix B. VSWR will be within the limits listed in
(35) Repeat technique of (26) through (34) above for remaining cardinal test point
frequencies determined in 7 c above.
(36) Connect equipment as shown in figure 5 and allow equipment to warm-up for 3 hours.
(37) Adjust programmable sweep generator CW-F1 frequency controls to first
cardinal test point frequency determined in 7c above.
(38) Adjust programmable sweep generator LEVEL output controls for +3 dBm.
(39) Determine signal generator frequency
(LO)
required
for
the
desired
measurement by calculating the following equation:
LO = (RF-IF) / 2
Where:
RF = Frequency of programmable sweep generator (37) above
IF = Intermediate frequency at which receiver system is to perform
measurement (0.700 GHz)
EXAMPLE:
Let IF = 0.700 GHz
Let RF = 18 GHz (37) above
Let LO = signal generator frequency
LO =
(RF-IF) / 2
LO =
(18 GHz-0.700 GHz) / 2
LO =
17.3 GHz / 2
LO =
8.65 GHz
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