Re: [Elecraft] KX3 Heatsink discussion

Hi Jan, Elecraft designed the KX twins to run with maximum efficiency, so up to 10 watts, it is the more efficient PA in the KX3 which supplies the output power with the KXPA100 in bypass, and when more than 10 watts is dialed in the KXPA100 is enabled, and the KX3 throttles back to make the

Re: [Elecraft] KX3 Heatsink discussion

OH ~ I think we all understand that the word "heat-sink" implies that it might/will get warm :-) BUT ~ I originally asked about the "heating" of the KX3 when driving the KXPA100 at 20W SO ~ I experimented this morning with adjusting the power OUT of the KX3 while driving the KXPA100

[Elecraft] KX3 Heatsink discussion

Sorry of this appears twice, I got a bounce on the first submission: The Pro Audio Engineering Kx32 Heatsink has more surface area than any other commercially available KX3 heatsink. Regarding mass, more is not necessarily better. If you take two heatsinks with the same surface area, on the

Re: [Elecraft] KX3 Heatsink discussion

Actually, that’s 63 C at the PA device location on the PC board. The outside surface of the heat sink itself is quite a bit lower in temperature. Wayne N6KR > On Aug 6, 2017, at 11:39 AM, Wayne Burdick wrote: > > The KX3 and KX2 max heat sink temperature is 63 C. At that

Re: [Elecraft] KX3 Heatsink discussion

The KX3 and KX2 max heat sink temperature is 63 C. At that point power is automatically dropped to 5 W. If it reaches the max temp again, transmit is exited. Wayne N6KR > On Aug 6, 2017, at 10:27 AM, Jim Brown wrote: > > A well designed output stage SHOULD be

Re: [Elecraft] KX3 Heatsink discussion

A well designed output stage SHOULD be hot to the touch. The temperature component of protection in Elecraft output stages seems to kick in when the internal temperature approaches 70 deg C. You can see this, for example, by watching temperature in the KPA500 and listening to fan speed. The

[Elecraft] KX3 Heatsink discussion

I'm puzzled by the comment posted yesterday: by Jim W7JR ""I've been doing a lot of FT-8 using my KX3 and my KXPA100 at 20 watts, and have noticed that the KX3 is heating up quite a bit and is almost hot to the touch"" Why should the KX3 be heating up, when the AMP is running only 20W ? Is the