Chatter-January 2016

Chatter by Art Lee WF6P

I was saddened to read that Leon Fletcher, AA6ZG(SK), passed away last month. Leon was our club president in the late 1990s when we met at the old Community Hospital conference room. We were close friends and enjoyed having lunch together often. Many times we were joined by Suellene, K6CPA, and Wayne, KB6KN, at the Crow’s Nest. Leon and I were also writing buddies with our club and the SLVARC newsletters. Leon was the editor of the SLVARC newsletter for several years. Once, we both had feature articles appear in the same issue of Monitoring Times Magazine (now defunct). Leon lived in Ben Lomond and was active on ham radio for over 20 years, even going on a DXpedition to a far away spot (Christmas Island?). About five years ago Alan Handforth, Dan Anderson and I took Leon’s tower down, ending Leon’s DXing. Alan lowered the tower in sections. Dan had just recovered from heart surgery and lifted more than his share, despite my telling him that I had it well in hand and for him to slack off. Dan ignored my protest and help throw the tower up onto his truck. Alan was very good at his work, even leaning over the edge of second story roof to plug the bolt holes and paint the facia board to match the other paint. Leon continued to be on the air on 2 meters.
Batteries. Always a fascinating subject for ham radio operators. We need ‘em and use ‘em a lot. We all know they can be dangerous, however. Look into the inner recesses of any old-timer mechanic’s tool box and you will find the weld marks on a wrench or other tool. Every mechanic has shorted a battery to ground one time or another. Usually only once is enough to discourage it from happening again. We are taught to NOT short out a battery and to never wear rings or metallic jewelry around batteries or machinery. Once, while working with ARES, Leon carried a spare battery pack for his hand-held in his pocket. While walking along, he felt something grow very hot in his pocket. When he pulled out the battery pack, he found it ready to burst into flame. A coin, a quarter, fit perfectly inside the battery pack slider track, shorting it out. “My pants were nearly on fire!” he said.
Recent aircraft fires as a result of thermal runaway in lithium-chemical batteries has brought our attention to this danger. This has long been a problem with large, multi-celled ni-cad batteries when charging. Great care has gone into the control of this process. Basically, the total batteries in a pack try to bring up the voltage level of their multiple companions consisting of dozens of cells. With all the batteries trying to “pump up” the charge of a deficient battery, heat build-up causes a breakdown of the battery insulation. Temperatures above 1100 degrees ignite the hydrogen gas and an explosion follows. The FAA is experimenting with various explosion-proof boxes for use in aircraft. (“Fired UP” pp 64. AW&ST Dec7-20 2015.)
An interesting side story concerns air shipment and common use of the two-wheeled sidewalk craft popularly sold this past year. Several battery packs have exploded with one nearly setting fire to a home. These battery operated devices have been banned from being shipped or taken aboard commercial aircraft.