TL/DR: The antenna mod improved the signal strength reported for all my Z-wave devices, but I see only a minor improvement in routing. Things seem to have less overall delay. And Hub Protect Migrate is a great feature.
I set out to do the external antenna mod myself. but I was worried about messing up my hub.
In the end I asked @lewis.heidrick to do it for me. He did a great job and it took less than a week for the hub to go from here to him and back.
I had him modify my spare C-7 and I used Hub Protect to migrate my active meshes to the backup hub. This was a mostly painless process, and everything mostly just worked. I did this to avoid re-pairing my 24 Z-wave devices, but resetting the 120 Zigbee devices around the house was much more of a chore than I expected (it took 4 days, not the 4 hours I planned). There were some hiccups I didn't expect:
- my USB Z-wave stick needed to be re-included and one lamp paired non-S0 had to be excluded and re-included
- Zigbee water sensors stopped reporting battery until I specifically removed and then paired them
- my Sylvania Zigbee light strips were very challenging to reset
- a few apps needed their credentials updated (for incoming connections)
Overall, while the migrate is a great feature and it saved me tons of work. But, I hope I never have to do one again.
Back to the mod, I did this to improve my Z-wave network, which I've always considered weak. My Zigbee network has always worked robustly, with about a dozen repeates and 100 sensors (most of which report temperature).
Before the mod I used to have 8 or 9 DIRECT devices. After, I have 10 or 11.
I have 9 Inovelli Red Dimmers that I consider the core of my Z-wave network. 2 of them sit 9 feet away from the C-7 with direct line of site. These almost always route through other dimmers that were much further away from the hub. After the antenna mod, these now sometimes go DIRECT to the hub.
This are the Z-wave status taken after the hub was up for 36 hours, left from before (Feb 4) and right from after (Feb 18): (note the last 3 devices changed order)
