On Wed, May 7, 2014 at 7:05 AM, Nigel Vander Houwen <nigel@k7nvh.com> wrote:
And regarding graphing voltages, I'm similarly not certain there's much to be gained from that. We've used the voltage display to check on some of our cables to make sure they weren't offering crazy resistance, and potentially dropping voltage as current needs increased during high activity, but for non-specific testing, it seems to be that you'd be graphing how well regulated a cheap wall-wart is. As long as it's putting out enough to run the modem, it shouldn't be a problem.
I'm graphing voltage at home. My Mikrotik router and cable modem are powered by my shack 13V supply and battery bank. Graphing voltage tells me whether I'm on external or battery power. I have it configured to send me an email if the batteries get low. This same scheme could be used to monitor power at a repeater site. Since I'm using the Mikrotik internal voltmeter, there's no extra hardware beyond your standard HamWAN modem (though in my case, it's an RB2011). We might want to graph voltage at Haystack. Since it's solar powered, it'll be more interesting to watch than "a cheap wall-wart." Tom KD7LXL