Yep!!! Thermal Design.... you can bend the rules of physics, but one cannot break them.
Yet another reason beyond packaging to put the power supply in a separate package. Sounds like an excellent engineering approach/trade-off. And the three fully exposed/unobstructed fans on the back panel are almost begging for custom ductwork to deliver nice 76 F (24.4 C) air supply (lightly pressurized via HVAC). Less fan "on" time and mitigation for fan noise... Lot of flexibility to supplement thermal control if you're obsessive like me.... or not.... if you're normal like most folks. :-) 73, ______________________ Clay Autery, KY5G On 4/21/2017 2:25 PM, Wayne Burdick wrote: > Hi Paul, > > To protect the amp and T/R switch, we’re using heavy-duty PIN diodes, very > high reverse voltage, and virtually instantaneous detection of high SWR. All > possible catastrophic load scenarios have been extensively tested. > > On fans: > > We started with a humongous custom heat sink extrusion and thick copper > spreader, optimized for our packaging. We also use two LDMOS devices rather > than one, allowing heat to be distributed across all that heavy metal much > more effectively. This slows fan onset time. (Some competing compact amps use > inadequate heat sinking, with predictable results.) > > Next, we added three large, deep fans. The center fan is controlled > independently so it can turn on first, at low speed. In many cases that's all > you'll ever hear. Only during high duty-cycle operation are the other two > fans turned on. We then carefully manage the speed of all three. > > Ultimately, you have to get rid of the heat. But our goal is always to > minimize noise. > > 73, > Wayne > N6KR ______________________________________________________________ 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
