Home |
Search |
Today's Posts |
#16
|
|||
|
|||
measuring cable loss
BTW, directional wattmeters for the ham market are often not capable of reasonable accuracy on loads other than the nominal 50 ohm load. There are a range of tests that such an instrument should satisfy, but for hams, it is usually considered sufficient if the "reflected" reading is approximately zero on a 50 ohm load. I should think, though, that one could calibrate such a reflectometer/directional wattmeter. That is, you could test it with a suitable variety of source and load impedances and develop a fairly simple arithmetic correction that would be accurate. The interesting question might be whether you could unambiguously take a particular fwd and rev reading and turn that into a true fwd and true rev, essentially solving for the mismatch. Down in the lab here at work we have a whole rack of precision misterminations (1.1:1, 1.2:1, 1.5:1, etc.) that some talented engineer built and calibrated some decades ago. They're built on the Maury bluedot N terminations. Owen |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Measuring quarter wave cable length with HP 8405A | Antenna | |||
Calculating Coaxial Cable Loss | Antenna | |||
Antenna cable loss query | Scanner | |||
Antenna cable loss query | Shortwave | |||
Measuring small inductances using a return loss bridge | Homebrew |