Don: Depends on the UPS...
in the case of APC, the "Back-Ups" models are "Standby" types, and yes, the inverters only run when the AC fails and power is being drawn by the batteries. However, in the case of APC "Smart-UPS", "Back-UPS Pro" and TrippLite "SmartPro" models, these are "Line Interactive" types and the inverter is ALWAYS on, when AC is on, it charges the battery, but when AC is off it powers the AC output. In all cases of the above, some, mostly the less expensive APC models, are "Modified Sine Wave" which is a rather nasty looking stepped square wave like waveform with lots of harmonics. TrippLite UPS's, at least the SmartPro models I use at work, are very close if not identical to true sine wave output. Check with a scope before placing these anywhere near a receiver. I learned this the hard way with a company surplus APC 1kw unit that I brought home, re-batteried and put into service on my shack PC's. This UPS made 40 and 80 meters unuseable. Removing it and replacing it with a pair of APC 500w Back-Ups (the cheap $40 Office Depot ones) cured the problem while on AC power. I agree; If you want to do an "orderly" shutdown, a simple STANDBY mode UPS will allow you to do this. If you want to keep transmitting, the West Mountain PowerGate is a great solution. See your local Server Farm Administrator and buy him/her lunch so he/she will think of you when he/she replaces the Farm's UPS batteries every couple of years on a set schedule. Recently pulled sealed AGM-type ex-UPS batteries will still have a couple of years life left in them when replaced by these guys. They are great for this duty... They are the size of a automobile wet cell, maybe a little bigger, but bring your hand cart, these suckers are really, really heavy! :) BTW, Im getting used to the "backwards" SPAN control on my P3; mentally uncoupling WIDTH from SPAN helped. I will have my feeble mind retrained probably by the end of my NAQP SSB shift from my club this weekend... :) -lu-w4lt- ---------------- Message: 6 Date: Thu, 18 Aug 2011 14:42:25 -0400 From: Don Wilhelm <w3...@embarqmail.com> Subject: Re: [Elecraft] K3-Front panel shut down question. To: elecraft@mailman.qth.net Message-ID: <4e4d5d11.2030...@embarqmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Someone also mentioned that the UPS might generate some hash - BUT that would only be true if the AC is removed from the UPS. Under normal conditions with AC present, the inverter is not active. It was not the initial question, but -- if you want to keep transmitting after an outage, you will have to implement the large battery solutions that have been mentioned. 73, Don W3FPR ______________________________________________________________ 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
