[Elecraft] KX2 heatsink

[Wayne Burdick]

Auto power reduction happens at 63 C. But it may very well have gone down to 55 C awhile after dropping to 5 W. 

Wayne
N6KR

----
http://www.elecraft.com

> On Jun 18, 2017, at 4:38 PM, Ron D'Eau Claire <ron at cobi.biz> wrote:
> 
> Sri, I meant the temp was 55C, not 45C after the automatic power reduction
> kicked in. 
> 
> 73 Ron AC7AC
> 
> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Ron D'Eau Claire
> Sent: Sunday, June 18, 2017 4:28 PM
> To: 'Irma & Linas(LY2H)'; elecraft at mailman.qth.net
> Subject: Re: [Elecraft] KX2 heatsink
> 
> Fired up my "stock from the factory" KX2 into a dummy load at 10 watts, key
> down, and it dropped to 5 watts after 4 minutes running from a 13.8 vdc
> supply.  PA temp was about 45C. 
> 
> Hope that helps with your analysis.
> 
> 73, Ron AC7AC
> 
> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Irma & Linas(LY2H)
> Sent: Sunday, June 18, 2017 2:33 PM
> To: elecraft at mailman.qth.net
> Subject: [Elecraft] KX2 heatsink
> 
> Hello folks,
> I am looking for the practical , empyrical, real info based on the
> individual measurements of the maximum Key-down time/temperature at the 10w
> output of the KX2 before it drops down to 5 W issuing a message of "HI
> TEMP". I would also like to learn about comparison of the KX2 stock heatsink
> vs the Pro-audio Engineering KX22 product.
> 
> The reason is that I have decided to install the KX22 on my KX2 ( # 148*)
> after a short dx-pedition to Aland islands in May. I was handling quite a
> pile-up from the hotel room and after some 5 min of intensive CQ-ing and
> answering on CW the PA temperature gone up to 59-60C degrees and the power
> dropped down to 5 W and it was frustrating :) Today I have installed the PAE
> KX22 heatsink. The key-down at 10 W into a dummy load in CW mode lasted for
> around 3 minutes starting from the ambient temp. 27C. I don't think this is
> very impressive baring in mind the Pro-audio's  claim of the 250% key-down
> time improvement. Unfortunately, I was not so smart to test the key-down
> time with the stock heatsink before I changed it to the new one, :) But I
> remember Wayne was posting  here in the previous thread something abt 7 min
> of key-down at 10W... So, with the 250% improvement with the KX22 it should
> last... for some 24 min?! in my case, It doesn't sound very realistic ,
> neither 7 min with the stock heatsink, nor 24 min with the Pro-Audio ( maybe
> ,bad thermal contact, not enough of grease?). That's why it would be very
> interesting  to compare the real-life empyrical data of the other KX2
> owners.
> 
> 73! Linas LY2H
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