TB 9-5985-314-24
CALIBRATION PROCESS FOR
COAXIAL CIRCULATORS
15. Preliminary Instructions
a. The instructions outlined in paragraphs 15 through 17 are preparatory to the
calibration process. Personnel should become familiar with the entire bulletin before
b. Items of equipment used in this procedure are referenced within the text by
common name.
c. Unless otherwise specified, verify the results of each test and, whenever the test
requirement is not met, take corrective action before continuing with the calibration.
16. Definitions. Explanation of terms peculiar to coaxial circulators is listed in a through
d below to ensure accurate interpretation of the measurement techniques used in
this procedure.
a. Isolation. Electrical or acoustical separation between two locations is normally
expressed in dB (a measurement against energy flow).
b. Insertion loss. The difference between the power received at the load before and
after the insertion of apparatus at some point in the line and normally expressed in dB (a
measurement made with forward energy flow).
c. Forward energy flow. The direction in which energy is allowed to pass through a
device with very little RF loss.
d. Reverse energy flow. The direction in which RF energy is opposed in passing
through the device.
NOTE
Use Appendix C to determine TI parameters for isolation and
insertion loss.