[TowerTalk] help identify remote coax/antenna switch please

[K4IDC@comcast.net]

I have several of these that I've acquired lately...wondering if anyone on
the list can identify in terms of make/model or if it's a homebrew. One or
two are mounted in nice weatherproof cabinets. I'd like to know if the
switching voltage is required to be constant or if it's a pulse activated
design.
Photos here:
https://drive.google.com/open?id=1tDaIimDk8ybLlSdB8Xl-BDWn9QTm0VNP


Thanks,
Robin Midgett K4IDC