I had good luck with the first Netgear r6700v2 running snapshot with stable 2.4 ghz and 5 ghz that I decided to get a second r6700v2. In this second router, I was only able to set the transmit power to 6 dBm both in 2.4 and 5g (with luci). Needless to say, performance is poor for my intended purpose - as a dumb AP linked with a 5g WDS (or 802.11s) backend. I've pushed most of my clients to 2.4ghz.
Searching around, there's some posts about Sercomm patches, parsing bad blocks on NAND, etc.
I did a hexdump on the factory partition (which supposedly contains the calibration info) and indeed 00000000 is empty and 00020000 starts with 15 17.
Hexdump of my working r6700v2 starts with the 15 17 right from 00000000.
I read some conflicting info about patches that addresses this making its way into MASTER. Is there a fix in the works? What can I do to get more than 6 dBm? Can I somehow copy the factory partition from my working router to the low-powered one?
For now, the easier fix is to adapt the DTS to the 'correct' memory address and compile your own image. The more complex fix is to apply the patch set mentioned in one of the other topics about transmit power issues on these Sercomm devices. But from what I recall, that patch set has not gotten any reviews or traction whatsoever... And the reviewing backlog is substantial.
No. Calibration data is device specific. Your device will perform worse with 'second hand' calibration data.
Tip: make a backup of your calibration data (as well as your bootloader, to be on the safe side) and store it somewhere. Calibration data cannot be restored by reinstalling OEM (or any other firmware), exactly because it's device specific.
I was (surprizingly) successful in following the directions, modifying the DTS, and compiling my own image.
I seem to have lost the ability to grab packages (opkg update). I know very little about the build system. Is there a way to create images that can utilize the packages online?
Also, any tips to create the image faster? I'm building this on an i7 laptop that is several years old. Still took, maybe an hour or two?
I did "make menuconfig", selected additional packages (added wpad-wolfssl, etc), then "make -j8 download world".
Thank you for all your help. I would have preferred to be able to flash the same image on both my r6700v2 routers, but this will do for now. Hopefully the sercomm patch will be implemented into the official system soon.