DIRECTlONAL_WATrMETER

Published:2009/6/28 22:50:00 Author:May | From:SeekIC

Gives 1070 accuracy between about 100 kHz and 70 MHz. Fullscale values of ranges are 1,10,100, and 1000 W. Low resistance in secondary circuit of current transformer is split into two equal parts, so sum and difference voltages are available at ends of secondary. Meters then indicate forward and reflected power values. For 50ohm line, use 220 for R2 and 27 for R3 and R4. For 75-ohm line, corresponding values are 180 and 33.Detector diodes are point-contact germanium rated at 80 PIV. Artide gives construction details. Ground coax braid at one end only. Ferrite 4ecring is 0.5-inch Mullard FX1596 or equiva-lent.-P. G. Martin, Some Directional Wattme-ters and a Novel SWR Meter, 73 Magazine, Aug.1974, p 17, 19-21, 23-24, and 26.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Measuring_and_Test_Circuit/DIRECTlONAL_WATrMETER.html

Print this Page | Comments | Reading(3)