Measuring Cable Loss; Other Applications - AEA CIA-HF Operating Manual

If there is a known fault on the cable, and the distance to fault ("FT:") reading seems inaccurate,
verify that the open termination is truly an infinite DC open, or that the short is a direct short with
no inductance. An incorrect velocity factor will also contribute to an inaccurate footage reading.
Occasionally, a cable's true velocity factor will vary from the published or manufacturer
specification because of a production variance or because of cable deterioration due to ultraviolet
or water contamination. Please note that since the velocity factor is allotted only two decimal
places, it is not possible to measure distance with better than 1% accuracy.

MEASURING CABLE LOSS

Example: Determining cable loss.
Process:
1. Turn the Analyzer on.
2. Before you attach the cable under test, enter the center frequency at which you want to
determine Return Loss.
3. Use F3 to scroll to the "SWR:xxx RL:xxx" data block. The "RL:" reading should be less than 2
dB, depending on the center frequency selected. Note this reading.
4. Now attach the cable under test to the antenna connector. Note the new Return Loss
reading. Confirm that the cable under test has either a direct short or a complete open at the
termination end.
5. Subtract the initial Return Loss reading (without the cable connected) from the new reading.
The result is the total (round-trip) Return Loss present in the cable.
6. Divide the result by two (2) to determine actual cable loss (one-way) at the selected center
frequency.

OTHER APPLICATIONS

Uses for the CIA-HF Analyzer are limited only by your imagination and experience. We
encourage you to explore all of the Analyzer's capabilities – those listed here and those wanting
to be discovered. For more information on Antenna Impedance Matching, consult the ARRL
Antenna Handbook.
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