Checkout of SimSmith v16.3 – spot check of transmission line database

I am not a SimSmith user, and with upgrade of my desktop computer, I have lost access to the Smith chart application I have used for 20+ years. That has given me reason to evaluate various Smith chart applications for a replacement.

Smith charts are about modelling problems in transmission line terms, and what better test than a simple transmission line problem.

Above, a model of Belden 8216 (an RG-174 type cable) picked from SimSmith’s library of transmission line data (source KN5L). The model is at 1MHz and essentially indicates the Matched Line Loss of 100m by deducting the left hand dBW figure from the next one to the right, -5.88228e-3–2.33357=2.33dB. (Duh, I could not copy and paste these values, they had to be read and typed in by hand which is not only laborious but more importantly gives scope for error.)

Lets check the Manufacturer’s data sheet.

Well that is not too good, the manufacturers MLL is almost three times that given by SimSmith.

There is another entry in the TL database for Belden 8216, and it produces results much closer to the datasheet in this instance.