Monday, February 28, 2011
Test Results for 195, 240 and 400 Cables
15 metres of 400 cable , N male conns each end. N30N30-400-15000
Loss at 2.45 GHz = 3.8dB
This measurement is consistent with 0.22dB loss per metre and 0.25dB for each connector.
(15 x 0.22) + (2 x 0.25) = 3.8dB.
Comment on measuring loss in long cables using a VNA.
Slow down the sweep time until you get a consistent measurement! I found this out the hard way myself, and, nearly always, whenever customers have challenged the specs on supplied cables it has turned out to be a measurement issue.