on a more on topic note...
out with the 4 years old Tram 1180 38" HAM Antenna

(pic grabbed from Amazon)
In with the Comet SS-680SBNMO :

(pic also grabbed from Amazon)
The Comet is about 8" shorter but has a spring base, which is what I was looking for as replacement.
The problem:
I knew from Day 1 that the Tram 1180 mounted on the A-Pillar light mount whips around a lot when the going gets tough and at highway speed. But I put up with it because to me the transmission distance is more important due to the larger convoy that we usually had at the time and I was always running tail gunner because I was one of the only two people who had mobile radios. This was in 2021.
When I swapped all these over to the Rebel in late 2022, the problem remained but it was not that big of a deal because we only had THREE mobile radios in our 10+ cars convoy. We space out even more as we all upgraded suspension and go faster in the desert, so now it's the lead, mid, and I relaying messages in the convoy. TX and RX range was still important for us, and being the sweeper I was as fast as the slowest guy in the convoy so I put up with it.
In 2023 when I swapped over to the Baja Designs XL Racers for my A-Pillar lights, I noticed that the whipping movement plus the weight of the XL Racers create a lot of unwanted vibration during highway driving and on the trail. Still, I put up with it because we did not get more mobile radio, and yet our convoy grew in size.
In 2024, I was getting fed up with this unwanted vibration, but I was focusing most of my energy on the Alaska/ Arctic Ocean trip so I didn't think much. It was also this year the amount of mobile HAM radios grew in our convoy (we now have over 5 mobile radios, 1 kenwood and at least 4 more iCom IC-2730A that I put in for the boys)
In 2025, almost everyone who comes out to play has a mobile radio. I am off the sweeper duty as a result and I can finally go as fast as I want, and that amplified the vibration problem. In addition, the possibility of metal fatigue of the A-Pillar mount as a result of this unwanted vibration is now a concern for me. I mean, all these forces of antenna movement gotta go somewhere, and since the base of antenna is attached to the A-Pillar and the base is not moving, it seems like the force is transferred to the A-Pillar mount made by bending and welding metal pieces together. It only make sense that if something is going to break from metal fatigue/ vibration, the bends and welds of the A-Pillar Mount will be ground zero since it's the weakest point (mount is attached to the hood hinge, on a bigger plane that is also not moving). I know it is very unlikely for SDHQ A-Pillar mounts from getting metal fatigue from this vibration, but it is always a possibility and if anything, I was looking for an excuse to swap this whip out.
The solution:
Since I don't have any HAM radio expert friends, Google AI and ChatGPT became my best friends. Per their suggestion, vibration is caused by a stiff antenna base and long antenna. To fix this issue, a spring base will help tremendously as the spring will absorb the movement caused by antenna whipping. In addition, a shorter antenna will reduce the pendulum effect as well, further reduce the force that create vibration on the A-Pillar Mount. Per AI, a shorter antenna is actually more beneficial than the long antennas for A-pillar mount, as the signal would be broadcasted in a more broad cone than a more focused beam from longer antennas. (That part doesn't really make sense to me but... I cross referenced both Google AL and ChatGPT and both give the same answer... so, I don't know lol)
Anyways, both AI services recommend Comet SS-680SBNMO as the best antenna for my application, so... here we are.
The verdict:
I've yet to do a TX and RX test with the new antenna, and not sure when I'll be doing that. So I can't comment on the TX and RX portion just yet. I will still keep the Tram 1180 in the truck just in case though.
I haven't tried the antenna on the trail yet, and I don't know when that's happening. However, on highway I noticed the usual antenna whipping and A-Pillar mount vibration is now gone, so my theory is heading toward the right direction, I guess.
I purposely avoided those "shorty" type of antenna because frankly, those are junk. Tried that on one of the trucks in the convoy once, and it was terrible. I couldn't hear the TX when the truck was merely 0.3 mile away with no direct line of sight (just a few corners behind). That "shorty" came off immediately once we got to camp that afternoon and a spare Tram 1180 was installed, and the "shorty" was wrapped in the trash bag. That TX quality was even worse than Baofeng 8W handheld radios (radio used was same as mine, iCom IC-2730A 50W radio)
Will update with installed pics and thoughts whenever I go on a run.