A friend and I have been corresponding about seeming anomalies in results obtained when attempting to measure cable loss with the MFJ-259B. With the opposite end of a 50-ohm cable open, the manual sa
Pete, When sweeping feedlines at cell sites, we use (max+min)/2 (over the frequency range of interest) for cable loss (cable terminated in a precision short). This gives a number that is somewhat (20
Are these swings with the frequency held constant? Or wavyness as the cable is swept in frequency. Part of it might be that the bridge in the 259 has better accuracies at some impedances than others.
It's the latter, and I bet you're right about the variations in accuracy with impedance. The manual states "...The impedance meter is disabled in this mode." Perhaps all they mean is the front panel
rather than sweeping the cable with it open, you might try sweeping it with a known mismatch at the other end (e.g. two 50 ohm loads in parallel with a "T"). that way, the match at the meter will alw
Author: "Bob Newton W5RN" <rj.newton.w5rn@verizon.net>
Date: Thu, 15 Jun 2006 14:03:45 -0700
The method for the Autuk VA1 is as follows: From Instructions for the Vector RX Antenna Analyst Model VA1 IMPEDANCE (Z) METHOD Either open or short the line and find the minimum Z at the nulls. The c