I have two roughly 50m lengths of unterminated hardline that I swept in
TDR mode using a RigExpert AA-600. Each has an N-connector on one end.
The first length is Commscope CR-540PE (smoothwall 1/2" heliax) and it
shows a good result with no discontinuities in impulse response or step
response until the end of the cable, with the step response reflection
coefficient at zero the entire run. The other length is Andrew FJS4-50B
(corrugated 1/2" heliax). The impulse response is ok but the step
response reflection coefficient drifts negative over the length of the
run, ending at about -0.5 at the terminal end.
Why does the FSJ4 show that result? Note that when terminating that run
into 50 ohms, the step response reflection coefficient is zero across
the run.
John K7LY
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|