In my personal opinion, it is not a bad location…for the older flex, and current FlexM1
and maybe, the FlexNT
For me, I think these Flexies have far more flex to them and are more forgiving when flexing through the fulcrum than the newer flex PCB can flex
If you simply look at the design, you can see why
* not to scale
The PCB Flex has been tested under flexion, but not to the extremes that would be expected in the knife edge, so it is perfectly fine for other flat locations. It is a PCB after all, remembering the word flex refers to polymer material, NOT the antenna.
I fully planned to install my APEX Flex in my knife edge, back when it was looking like it would be a copper-style antenna. They are not, so I did not.
I know there have been copper flexies installed in the knife edge, but I don’t know of any failures, that is not to say there haven’t been, I just can’t recall any, but, I know of PCB Flexies being installed in the knife edge and a couple of failures, that being said, the hand still needs to be on the larger side to take a copper flexie as the copper flexies are longer than the PCB flexies.
My further observations, and not a fair side-by-side comparison, so take this for what it is worth.
The read range / coupling is noticeably better between my FlexM1 than my ApexFlex and FlexDF2
HOWEVER, as stated, this is not a fair comparison, due to the individual chip’s power and processing requirements. merely an observation, but I do have a test I want to do to “prove” the difference.
I do not have, nor have I ever had a Copper nor PCB Flex in my knife edge, so to reiterate, this is all just my personal opinion, for what it’s worth.
The knife edge is still a viable location for me with a Copper Flex, even though I have little girly hands.
I will document it if/when I ever do