Ted’s essays

Ted Dunlap, STEE

You have-to have initials after your name to lend credibility to your projects and pronouncements. My latest creation inspired me to append “STEE” to my name. Further explanation will wreck the aura, but I’ll go ahead anyway. It stands for Shade Tree Electrical Engineer… similar to the Shade Tree Mechanic title I earned repeatedly with my auto/truck/motorcycle/tractor repair toolset.

Running a ham radio shack requires steady, clean 12-volt electricity. Handheld transceivers, HTs, or walkie-talkies if you prefer, have their own batteries. Cheaper ones use AA or AAA, but most use rechargeables whose chargers plug into standard 120-volt household outlets. Our mobiles and base units all run on 12-volt direct current in our shacks, vehicles or deployed field stations.

I selected solar-charged 12-volt deep-cycle marine battery for my first radio shack. It cost more than triple that of a good 12-volt power supply running on household power, but ham radio for me is about emergency communications, and many emergencies involve absence of household power. An off-grid solar/battery system cares not what the grid is up to.

My first system was designed and sourced by a proclaimed expert solar engineer who turned out to be more of a legend in her own mind than fully qualified. It did not do everything I asked for, but has been running my radio shack for several years now.

I had excess charging capacity at times, so added second and third lead-acid batteries last fall, then managed to over-use the system. That lead to a larger solar panel and controller. I got that hung up and connected only to find my new controller inadequate … or my solar collector excessively powerful (actually 50% more peak power than I was told to expect). Either way, I had to order a new, more capable controller. That is a week or two away.

Meanwhile I need to keep my batteries charged somehow.

The right way being unavailable right now, the shade tree engineer went to work.

A week or two of connecting and disconnecting power cables entering the controller was discounted right away. Ah, but I have a few blade switches that would be happy to do the job. The juice from panel to controller is now detoured through a handy manual switch.

I close the switch at night so that the early morning solar energy enables the too-small controller to recharge my batteries before the full force of the solar panel overwhelms it by mid-day… at which point I open (disconnect) the switch for the rest of the day.

Shady, perhaps, but it will work until the right part gets here (that I ordered from a reputable solar energy specialty store).