I have a question on adjusting the length of my 108” whip on my mobile. When using my rig expert zoom 35 analyzer at the antenna feed point I get a different reading than when at the radio. I understand that the coax acts as an impedance transformer so I assume that’s the difference. My question is should I trim the antenna for resonance wi th the analyzer at the feedpoint of the antenna or at the beginning of the coax or use an electrical 1/2 wave length of coax at the frequency I plan on using? I’ve gone thru the trouble of bonding the body panels together and bonding the cab and bed to the frame. Made sure the exhaust is bonded in 3 places and that my mount is very well positioned and grounded. I’ve taken great care in running LMR400 and 2 gauge power run directly to the positive terminal and the ground immediately adjacent to the negative terminal on the body. I’ve upgraded all the engine grounds and alternator wiring to the battery. I’ve even wound a common mode choke at the feedpoint of the antenna. My point being I’ve tried to maximize performance and it may be minimal but I’d like to extract everything I can outta the system and want to make sure I’m resonating the antenna properly. If needed I was going to use a tuning stub if once the antenna is resonant the feedpoint impedance was less than 50 ohms. Any guidance would be greatly appreciated. oh almost forgot current reading at the feedpoint is freq. 27.385 swr 1.05 Z=53.35-j0.05 ohm
And at the radio is freq. 27.385 Swr 1.73
Z=29.83-j7.23. To me it looks as the antenna is very near resonance when measured at the feedpoint. Is this a correct assumption being that the reactive inductance are nearly at zero j0.05. Thank you
And at the radio is freq. 27.385 Swr 1.73
Z=29.83-j7.23. To me it looks as the antenna is very near resonance when measured at the feedpoint. Is this a correct assumption being that the reactive inductance are nearly at zero j0.05. Thank you
