The original request for aftermarket heat link was from earlier production of KX3. My KX3 was an early production. I plainly put up heat sink issue in this mailing list that the early KX3 only has thin piece of metal as heat sink which simply did not meet the specifications published by Elecraft. Eventually, Elecraft did respond and now newer production comes with KX3HSMDKT
I believe Elecraft learnt this lesson and the heat sink in KX2 will meet the published operating specifications. For pro-long full duty cycle digital operation at 10W, KX2 is simply not designed for that usage hence the stock heat sink. Heat sink problem also exists in the Elecraft transverters, while the max output is 20W, it cannot sustain 10W FM causal operation (i.e. too hot) 73 Johnny VR2XMC 寄件人︰ Howard Hoyt <hh...@mebtel.net> 收件人︰ elecraft@mailman.qth.net; elecraft-requ...@mailman.qth.net 傳送日期︰ 2017年05月15日 (週一) 5:19 AM 主題︰ [Elecraft] KX2 Heatsink Hi Kev, The issue is related to the fact that Elecraft, as do virtually all amateur radio manufacturers rate power output with 50% duty cycle SSB/CW modes only. As is stated in the KX3 specifications and here copied from the KX2 manual: /"80-17 meters, 10 W PEP max (+/- 1 dB); 12 and 10 meters, 8 W PEP max (+/- 1 dB).// //Recommended transmit duty cycle: 50%, all modes. (If power amplifier temperature or// //current drain is too high, power will automatically be reduced.)// //NOTE: When using over 5 W in SSB, DATA-A and AFSK-A modes, the// //recommended supply voltage is 12 V or higher to minimize transmit intermodulation// //products. Higher power with lower voltages should be used only when necessary."/ I believe many or most of the requests we have had to make an aftermarket heatsink have come from hams using these rigs in digital modes such as JT and desire full-power operation, which Elecraft does not explicitly endorse, but which is possible with additional cooling. Elecraft designs and specifies operation of their rigs very conservatively compared to many other manufacturers, and the KX2 and KX3 specifications are spot on. Also as is stated in the specification, the KX2 internal battery, at 10-11V depending on state of charge is considered adequate for 5W or less, and we have supplied many Kx33 14V supplies to KX2 owners who want to use the rig at 10W power when AC power is available. I conclude many of these KX2 rigs are being used in digital modes from fixed location AC power, not from batteries. I can't blame the hams who do this, the KX2 is a fantastically full-featured rig for fixed operation, I have used it at home to check into local 10M SSB nets driving a KPA500 and no one was the wiser compared to my K3. Cheers, Howie - WA4PSC On 5/14/2017 4:01 PM, elecraft-requ...@mailman.qth.net wrote: >>It seems odd to me that an issue like this would go unmentioned >> and unaddressed by Elecraft. >> >>73, >>Kev K4VD ______________________________________________________________ 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 vr2...@yahoo.com.hk ______________________________________________________________ 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
