On 10/11/2012 5:01 AM, Bill wrote: > I have a very large deep discharge battery and the West Mountain > distribution and charging stuff.
Since 2004, I've been using the biggest deep discharge that Costco sells, float-charged by a 10A switcher that I paid $10 for at a hamfest. It was VERY noisy until I did suppression on it with toroids and capacitors. Batteries typically last four years and provide great backup power. I have two K3s in an SO2R setup, two batteries, two chargers, all wired in parallel. As to Joe's comments re: IMD -- short fat copper from battery to K3 helps minimize the drop. I do NOT use any charge regulator circuit, but have the regulator in the 10A supply set for 13.8V, which has proved very good for battery longevity. The result is about 12.3VDC keydown with 100W. I'm usually driving an amp, so my K3s are running between 30 and 45W, resulting in 12.6V keydown. I've looked at IMD with a spectrum analyzer (I own the same one that Elecraft uses), and it's been quite good, but I haven't studied the effect of power supply voltage. Several years ago I bought a PowerWorks 20A switcher to take on a DX trip, and checked it out for RF noise. I didn't hear any, but it mostly sits in my storage area. We used it in the same battery charging circuit for a California QSO Party county expedition last week and it worked well with no noise. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
