kidphc Posted April 24, 2021 Report Share Posted April 24, 2021 So building out my system for the truck. Finally, after a year of laziness I am building a center console (well the front half) to house a FTM400xdr and an Anytone at6666 10/12m radio (code for illegal cb radio for those that don't know). It will be used for 10m work as well. STAY TUNED FOR A BUILDOUT POST. So the antenna is mounted to the hood in front of the a pillar. Using a NMO34 with a 64" whip (10m) and a NMO30 with 64" whip(11m).This is going away. The whip is .100 and it flexes to 45 degrees above 30 mph and much more at 70. Incoming MFJ 10m hamstick. Should be tunable for both bands. I was trying to hold to Marc's talk about every commercial antenna for 11m is too short even with a spring. SIDE NOTE: I DID FIND SOME ONE THAT MAKE CUSTOM EXTENDERS TO GET A 102" TO 115" OR SO. Now back on track. The nmo34/30 combo the lowest I could get was a SWR of 1:1.6 or 1:1.7 with trimming. I gave up because the SWR started climbing back up. Lowest frequency for the 10m set up was 28.594 (VSWR OF 1:1.6). Just a hair away from the target of 28.400. It started making me think of antenna resonance and how to calculate it. So in order to find the resonant frequency of an antenna I am looking for an impedance of about 75 ohms purely resistive? This the value I gather for a dipole in free space. So the question is how the hell do I find resonance of a custom, less then ¹/4 wave whip with a bottom loaded coil? Sent from my SM-G975U using Tapatalk Quote Link to comment Share on other sites More sharing options...
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