Hi
DiSlord Coax Zc measurement function, already installed on H4 1.2.40 firmware, seems need to measure C0 capacitance @ 100Khz and the f0 first coax resonance frequency (Hz) and then we calculate Zc = 1/(4 x f0 x c0) Ohm , I appreciate it a lot.
Can we do some accuracy correction ? indeed diélectric permittivity of polyethylene diélectric can vary with fréquency , it can decrease slowly up to -4.5% from 100Khz to 14.1Mhz for example , so we can correct C0 value by -4.5% and then ZC should be increased by +4.5% to be more accurate @ 14 Mhz Zc measurement .
if our coax has 22.28 metre long with Vp around 83% , the first resonnance frequency will be around 2.71 Mhz wich still far from 14Mhz and may be some % error may be done , I prefer to measure the resonnance or antiresonance the nearest to the 14Mhz and devide by number for correction to have the more accurate Zc value based on measurement done as near as possible to the desired frequency ..
What you think about all this view , or DiSlord has already taken in consideration all this possible corrections .
73's Nizar .
