AnsweredAssumed Answered

Testing Insertion Loss

Question asked by Synergy2010 on Nov 9, 2010
Latest reply on Nov 12, 2010 by andyowen
My company has just obtained the 8753D network analyzer, and I am still new at it.
I am attempting to test for insertion loss. 
Test Requirements:
Insertion loss per 100ft
N-type to N-type
Frequency Range: 1GHz
Max Loss: 14dB

Network Analyzer Set up:
Measure: S21 Transmit
Format: Log Mag
Scale Ref: Auto Scale
Center: 1GHz
Span: 500MHz
Marker: 1GHz
AVG: Averaging ON  Smoothing ON

Problem: Most cables I test result in a -dB value which I am assuming is LOSS.  However, when testing a shorter cable, e.g. 18inches,the result is a positive value(e.g. .2378dB). Why is this ? am I interpreting this incorrectly or am I setting something up wrong?