If you’re at all into antennas aside from your handheld rubber duck antenna, you should try to get an antenna analyzer. Here I am using a RigExpert AA-600:
Before using this device, I would just go by the radio’s SWR reading (a poor display of SWR “bars”) to determine if I was close to resonance. The quad-band vertical antenna I have supposedly works with 10m, 6m, 2m, and 40cm. I never had much success with adjusting the end tip of the antenna for 10m until I started evaluating readings using the AA-600. My target frequency was 28.400 MHz for the LARC weekly 10m net, and 28.457 MHz for the SDARC weekly 10m net. Both frequencies had such high SWR that I could never get out very far.
Turns out I was lengthening/shortening the adjustment the opposite way I thought, so no wonder I had no success. I also found that the counterpoise placement has a huge effect on SWR readings, it’s very finicky.
Using MultiSWR mode, I am able to determine the effects of tuning across several bands in real-time. The above readings are what I was able to finally arrive at.
The RigExpert is a very sensitive piece of equipment and I was warned by a fellow ham to be wary of static charge and strong nearby RF, as it can fry the diodes of the analyzer. I cannot recommend an antenna analyzer enough. It is a true time-saver.