AdmiralCochrane

The Jeep CANbus is also known to have this problem. Heat gun can solve it, but I keep a spare in the glove box in case it happens on the road. Usually just makes flaky display notifications on the dash because the different sub-modules stop talking to each other.

There are counterfeits of almost everything that is good. It is possible that you bought fakes. There are websites that show how to tell the difference between the legit Nagoyas and Diamonds. Directly speaking of the fake Diamond antennas, they are obvious if you have had a real one in your hand and know what the real ones look like. Going back to your testing. You did not mention testing across the frequencies/bands for each antenna. Most usually favor one side of the band more than the other. Ideally they would be tuned for center, but that is less than optimal if you end up using it primarily on one end of the band or the other

What did you buy? I am considering the same

That's due to the American attitude that one can buy accuracy when it actually comes from practice over time. Much the same as buying health and strength with supplements and exotic fruits. Strength comes from work, not pills or powders. You and I both know that most even when they do buy a product that is actually better, if they lack the skill to use it properly, it doesn't work any better than a tool of lower quality and price. I have a couple of expensive Snap On screwdrivers that really are special in my hands, but in my son-in-law's hands they are no better than those from Harbor Freight.

I am pretty certain I hear legacy business fixed stations transmitting business data

Hams in my area are completely friendly to GMRS. Maybe a reciprocity problem some places.

I wouldn't bring diffraction into the conversation. Most likely just an obstruction than different antenna pattern.

My present feline stockpile is worthless. I used to have one that would run toward the door and growl when someone approached, better than any dog I ever owned. His size helped too.

Impress me and tell me you've done Delaware

WOW the price on them sure has skyrocketed. I didn't pay anything close to that for mine.

$450 ccr?? Name one

That is exactly what "maximizes contact time" means

Doppler shift maximizes contact time and clarity, but you can listen to most high passes without worrying about it

Much the same in central Maryland. Out in the sticks ... there is a phrase with F's that applies

More like $200,000 than $20,000. Not sure you can use deadly force to protect property outside of Texas. There is only one post suggesting using deadly force.