I wasn't worried, Dan. I know you are always tinkering and when you have the surge surpressor done please share it with us.
Bob
O.K. Bob (and anyone else that may be interested). Success today in locating the needed components to wrap this project up.


It's just your off-the-shelf telephone line junction box with two jacks. It makes it easy having 2 rows with screws for the connections and the 2 jacks are now in and out (or line side and equipment side). The TVS diodes and MOV (varistors) are packed inside on the bottom. The fuses are up on the top to make it easier to change them if/when needed, just loosen the associated 2 screws and swap the fuse(s) out. The earth ground screw comes out the back of the enclosure. It may be a better design to add a series resistor on each line between the MOV and TVS diode but I left these out because I don't want to add line loss to the already lengthy cable run. Total resistance between in and out for each individual line is an acceptable .2 ohms due to the fuse. I plugged it into my ws-2310 stn. and it's chugging right along and still happy.

The components are rated to kick in (clamp) around 6vdc which is the lowest I could locate. At least it's a lot closer to the dc voltage it's protecting than a telephone surge protector was. I have a 6 foot copper ground rod outside about 10 feet away that it's connected to. Total cost (excluding the existing grounding rod) was around $7(US).
This could also be placed outside where a wired anemometer and/or rain gauge enters the thermo/hygro ISS but you would need to remember to run a ground from there.
Added Note: This design is only intended to dissipate, or drain off, power surges/spikes in the equipment wiring. A direct hit from lightning will go its own course and circuitry such as this will have no effect suppressing it.