Figure 1:
Block Diagram of 1m spaced 64 foot long balanced line made from
AWG #18 magnet wire and connected to by a tapered transmission
line test fixture at each end.
Experiment 5
This Experiment is a measurement of a 64 foot length of 1m-spaced AWG#28 wire, fixtured using 200 ohm input Klopfenstein tapered transformers described in Appendix 2. A block diagram is shown in Figure1.
Calibration has been performed with 50 ohm SOLT calibration devices in a reference impedance of 50 ohms at the low impedance input connections of each tapered transmission line transformer.
Figure 1:
Block Diagram of 1m spaced 64 foot long balanced line made from
AWG #18 magnet wire and connected to by a tapered transmission
line test fixture at each end.
Measurement of this line was made in a very simple and straight-forward manner. Calibration, measurement and display is all done using only a nanoVNA-v2-plus4.
Over portions of the measured range the line is more than 10 wavelengths long and has a conductor spacing on the order of one half wavelength. Total insertion attenuation can be read from the blue trace of the VNA screen pictured in Figure 2. At 149 MHz where the spacing is one half wavelength, the total attenuation for the 80 foot total length, including fixture losses is about 3.8 dB.
Figure 2:
nanoVNA V2 Plus display including both the tapered fixtures and the 64
feet of line.
Figure 3:
1 meter spaced balanced line with Klopfenstein tapered transmission
line fixturing.