Johnny, Be confident that I will test at the 10 watt level (simulated FM) for a significant length of time, and also Eric's situation - 10 watts, 1 minute on, 1 minute off. I did similar stress testing on both large and small devices for the last 10 years of my professional career - I am quite familiar with the procedures required to test to specification - unfortunately, I do not have an environmental chamber available anymore to conduct the test at the highest ambient temperature allowed for the assembly, we will have to settle for a temperature rise measurement and extrapolate from there.
If the temperature goes above the power module's spec, I will terminate the test early (I don't want to produce a failure in someone else's transverter), but will attempt to run for your suggested period of time if the temperature stays within spec. Elecraft rates the transverters at 10 watts continuous duty and 20 watts intermittent, the output module is rated at 30 watts ICAS by the manufacturer, so Elecraft's rating should be conservative. This XV50 does have the vent holes on the bottom panel. While it is nice to keep things cool, sometimes the device manufacturer expects things to get too hot to touch comfortably. Despite my thoughts that it may be hotter than desirable, I have to have faith that the device manufacturer has done sufficient testing to substantiate his specifications - users should "hold the manufacturer's feet to the fire" if that is not true. We will see. 73, Don W3FPR Johnny Siu wrote: > Hello Don, > > The situation is - after I operate either XV144 or XV50 for a 10-15 minutes > QSO under 10w FM or 20 w SSB (the advertised rated output from Elecraft, p.3 > of the owner's manual), the bottom plate (or even one of side panels) is too > hot to be touched. > > I would be very interested in your findings and fully appreciate your > knowledge of Elecraft products. After your test, I would be grateful if you > could advise, it is all ok to operate the XV50 / XV144 under Elecraft's rated > output WITHOUT the need of any modifications to remedy the heat issues. > > It would be of great assistance if you could give your advice about the > maximum length of any QSO under the rated output. In other words, say for > example, I should not use the XV50 / XV144 for any QSO longer than 15 > minutes. Or, there should be 5 minutes cooling time between each 15 minutes > QSO etc. > > Thanks a lot in advance and look forward to your results. > > 73 > > Johnny VR2XMC > > > > ----- 郵件原件 ---- > 寄件人﹕ Don Wilhelm <w3...@embarqmail.com> > 收件人﹕ Eric <gliderboy1...@yahoo.com> > 副本(CC) "Elecraft@mailman.qth.net" <Elecraft@mailman.qth.net> > 傳送日期﹕ 2010/6/4 (五) 7:18:59 AM > 主題： Re: [Elecraft] XV50 cooling > > Eric, > > Have you actually measured the temperature rise? I am interested in > just how much is "excessively hot". > While it does get warm, I have always found the temperatures to be well > within spec for the output module. > > I have an XV50 here for repair right now. It is next in line for work, > and I intend to get to it this weekend. After it is repaired, I will > measure the temperature rise on the bottom panel right under the heat > spreader. I have a Fluke 279 with a temperature probe available. > > Report on Monday. > > 73, > Don W3FPR > > Eric wrote: > >> I have a late-model xv144 with holes in both top and bottom panels, >> connected to k3 with milliwatt drive. It runs excessively hot at 10w out in >> digital mode EME when used one minute on one minute off, so i dont think >> just getting new panels will help you. I use a small muffin fan blowing air >> underneath with the xv-144 up on the optional tilt stand and this simple >> solution works great. >> >> I also use an xv-432 for eme at 10w but its internal fan keeps it cool. >> >> Perhaps if enough people request a retrofit kit with an internal fan for the >> xv-50 and xv-144 Elecraft would consider it. I'd pony up. The fan could >> attach inside the top panel. >> >> 73 >> >> Eric WD6DBM >> >> >> > > > > > > ______________________________________________________________ > 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 ______________________________________________________________ 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
