I agree Dave. It's probably done for the same reason your TV and almost all other electronics in your household (including things like TVs, modern dishwashers, washing machines, etc.) in addition to your computer(s) are not truly "off" unless you unplug them.
It's the current "fashion" in engineering. Note that your K3/K3S works the same way but has no rear panel switch. The so-called 'parasitic power drain' of all those appliances in their "off" state adds up costs for the individual and for the community and the nation. In addition, the soft glow from LED's on the various appliances (thankfully not the Elecraft gear) can be deleterious to your health if they are allowed where you sleep. Studies have shown that even though you are not aware of it, their presence can interfere with normal sleep rhythms. A starry bright sky can be a pleasure at times but, frankly, us Humans evolved getting our best rest sleeping in a very dark cave. Personally, I have a master switch on my station that removes all power from everything. I power down individual equipment like the KPA500, K3, etc., then pull the "big switch". 73, Ron AC7AC -----Original Message----- From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Dave AD6A Sent: Tuesday, January 31, 2017 7:45 PM To: 'Elecraft Reflector' Subject: [Elecraft] KPA500 Power Supply Environmental/Ergonomic Issue I recently added a KPA500 kit for my home station. It went together just fine, and overall I love it. There is one thing about the way it works that bugs the engineer and environmentalist in me. Before I bought the PA, I thought I'd be able to turn it on/off entirely using the ON button on the front panel. I thought that maybe there was a supercap or backup battery that kept the button's electronics alive to perform the ON button function (like TV's have in them). However, it doesn't work like this. In order to turn the PA off completely, you have to turn off the main power switch on the rear panel. The front panel ON button powers up the PA from what looks like a cold state, however, my measurements are as follows: 1. With the main power switch on the back panel turned OFF, the PA takes no power at all (0.0W) 2. When you turn the main power switch on the back panel to ON, the PA draws 6.9W continuously from the 120V AC power supply 3. When you press the front panel ON button, the PA turns "ON" and takes around 13W (measured) in STBY mode My home station line up (K3s, P3, 2x SP3, KPA500, KAT500) sits on a large operating desk with a shelf unit that I build above the station. My computer monitors sit on the shelf above the radios. There is only just enough height clearance (about 2.5") between the top of the KPA500 and the underside of the shelf to allow me to put my hand over the top of the PA to reach the main power switch. It's fiddly but I can do it, it's just that it's a major inconvenience not being able to turn the KPA500 truly off from the front panel. Why is the KPA500 designed this way? In all good conscience, I can't live with the PA consuming 7W all day, every day - that's incredibly wasteful. I suppose I could put a more-easily-reachable external AC power switch on the side of my shelf unit to cut power to the whole desk, but that'd be ugly. I'd prefer that either a) the KPA500's main power switch was on the front panel, or b) the power supply system was redesigned so it only takes a few microwatts when power is applied but the ON button is OFF (not pressed, or pressed an even number of times). Comments? Ideas? Cheers, Dave AD6A --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ______________________________________________________________ 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 Message delivered to r...@elecraft.com ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com
