----- Original Message -----
From: "Al Williams" <firstname.lastname@example.org>
Sent: Monday, January 07, 2002 11:21 PM
Subject: coax loss
I have been trying to determine signal loss in coax by using a dual trace
oscilloscope (Tek 465) connected to the input and output of the coax.
However, instead of a loss I
am observing a gain!
My setup is using a MFJ-249 SWR Analyzer as the source and a BNC 51 ohm
resistor connected to the source. The opposite end of the coax is
to the scope and a 51 ohm carbon resistor with short leads. Both resistors
measure low swr (<l.2) with the MFJ.
The waveforms on input and output of the coax appear undistorted sinewaves
but the output is greater than the input for frequencies up to about 30
mhz. The output
increases as the coax length increases being about 20% greater with 130' of
LM400. The MFJ
measures SWR of about 2:1 (note; the two 50 ohm resistors at input and
output are in
Has anyone used this method? What might be wrong with my setup?
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