Plus Astrons have excellent overvoltage protection. The only RFI-induced malfunction I've ever been able to induce in an Astron is to trip that protector. It's a "crowbar" circuit that shuts of the output completely if it detects an over-voltage (typically something close to 15 VDC) on the output of a 13.8V supply.
I've seen them trip when running at a commercial mountain top repeater after a nearby lightning strike and in my shack when I don't have everything grounded and have an RF-rich environment feeding an end fed wire at a voltage loop so it makes my fluorescent desk light blink, Hi! In any case, no voltage above the crowbar limit ever got out of the supply and simply switching the supply off, then on again reset it. (Automatic reset circuits are often used on those mountain top units.) Ron AC7AC -----Original Message----- On 11/2/2010 4:54 PM, Bob Cunnings wrote: > "Analog or switching power supplies themselves are highly susceptible > to RF. A few millivolts of RF in the power supply can create an > instability which could lead to a catastrophic failure. We never > recommend regulated or switching power supplies because no one can > predict when RF is upsetting the power supply and all installations > differ in characteristics." This doesn't make any sense to me. Astrons and many others have been widely used in ham stations for decades, and these are all regulated supplies. Some are switchers, some are not. Indeed, that vast majority of 12V power supplies used by hams, and by commercial radio systems are regulated supplies. Rather, I strongly suspect that someone at SGC has a huge blank spot in the areas of RFI, the bonding of DC power lines, and how that DC power is obtained to provide power for accessories. This is an issue that W4TV has had to address with his various interface products. 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
