This compares well enough with my measurements... http://www.hamradio.me/graphs/connectors/UHFConnectorGraphs/Mismatch-Loss_1000.png
http://www.hamradio.me/graphs/connectors/UHFConnectorGraphs/Insertion-Loss_S21_1000.png Some of the longer UHF "barrels" show the repeating characteristic you observed which I assume is when the "different" transmission line is about 1/2 wavelength long. John, kx4o On 4/25/12 7:09 PM, Alan Bloom wrote: Since two N or UHF adapters were used, I assume the loss per connector is half the total. The vertical scale was .1 dB/division, so I estimated the insertion loss to the nearest .01 dB or so: --------- Type N -------- ---------- UHF ---------- FREQ (MHz) TOTAL LOSS PER CONNECTOR TOTAL LOSS PER CONNECTOR 1.8 0 dB 0 dB 0 dB 0 dB 30 0 0 0 0 100 0 0 0 0 150 0 0 0.02 0.01 200 0 0 0.03 0.015 450 0 0 0.18 0.09 600 0 0 0.26 0.13 900 0 0 0.66 0.33 1000 0.05 0.025 0.8 0.4 1300 0.1 0.05 0.86 0.43 1600 0.05 0.025 0.5 0.25 2000 0.05 0.025 0.02 0.01 Insertion loss increases until about 1300 MHz, and then starts to decrease until it is almost zero for the UHF connector at 2 GHz! At that frequency, the connectors are about 1/4 wave long (1 inch, assuming .66 velocity factor), so I assume that the two adapters are providing a conjugate match to each other. This confirms my assumption that the insertion loss is due to reflections (impedance mismatch), not absorption (true power loss). ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
