[Elecraft] K2/100 overheating?

[Don Wilhelm]

Ron,

My memory of the fan direction may be faulty, and I have responded.  I 
will check tomorrow.
I have just returned from Dayton (over 500 mile drive), so pardon me if 
I am a bit "groggy".  I will resolve all that tomorrow.

I did respond to George while I was at Dayton.  Yes, there are other 
situations that could produce those problems - usually those ate 
accociated with the T/R switch area.

73,
Don W3FPR

On 5/21/2017 10:44 PM, Ron D'Eau Claire wrote:
> Don: I guess you never noticed my response to Ken that I posted last Friday.
> The fan moves air INTO the K2, across the PA and it comes out around the
> heat sink fins near the front of the K2, just as George said.
>
> I suggested Ken contact you after he determined that he had in fact set the
> bias current correctly and the fan was operating correctly because you work
> on K2s quite often. It's been five years since mine was apart!
>
> 73, Ron AC7AC
>
> -----Original Message-----
> From: Elecraft [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Don
> Wilhelm
> Sent: Sunday, May 21, 2017 6:19 PM
> To: George Winship, NC5G; elecraft at mailman.qth.net
> Subject: Re: [Elecraft] K2/100 overheating?
>
> George,
>
> I will check the fan air flow direction tomorrow because I am uncertain.
> If you have the label out and the wires on the correct holes, yours is
> likely OK.
>
> There are 2 philosophies about the fan direction.  One is that you should
> exhaust the heat and let the assembly draw cool air across the hot
> components.
>
> The other says to let the fan "blow" on the hot components.
> The major difference between the two is that a blower fan adds heat to the
> air (due to the work produced by the fan), but adds the benefit of directing
> the air flow to the area to be cooled.
> An exhaust fan does not add its work product heat to the air being moved,
> but the cool air cannot be directed as well because it is spread over a
> large area in the enclosure box.
>
> 73,
> Don W3FPR
>
> On 5/21/2017 11:26 AM, George Winship, NC5G wrote:
>> Interesting. I built my K2/100 about 17 years ago and the fan has always
>> drawn air into the cabinet and exhausted over the heatsink. So, I
> rechecked
>> the manual and disassembled my rig to check for proper assembly. Fan label
>> is facing out and wires are soldered to the right pads(red=+, black=-).
> Was
>> there maybe a change in later models?
>>
>> 73, George
>>
>>
>>
>> Make certain the fan is mounted with the label out and that the red wire
>> is in the +hole and the black one in the -hole.
>> The fan should exhaust the hot air.  Cooler air flows in at the front of
>> the heatsink.
>>
>>
>>
>>
>>
>>
>>
>> --
>> View this message in context:
> http://elecraft.365791.n2.nabble.com/K2-100-overheating-tp7630828p7630883.ht
> ml
>> Sent from the Elecraft mailing list archive at Nabble.com.
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