[Elecraft] K3 Heat

[David Wilburn]

The fail temperature of the PA's is going to be well known and 
documented.  Then a safety factor is added.  But I seem to recall that 
early comments on heat design criteria was for 10m key down, 100% duty 
cycle, without damage.  But that is just the memory talking.  YMMV

73

Dave Wilburn
NM4M

rfenabled at gmail.com wrote:
> I am now wondering how do you settle on "Normal", "Heavy" and simply "Flat out" to come up with a "design limitation?" From the factory?
> 
> Much conjecture and pure guesswork has been written in recent posts as well as some very informative opinions on the cooling system used by Elecraft.
> 
> Perhaps we should hear from Elecraft on what design criteria was used when the decision was made to use the existing cooling arrangement.
> 
> Does the addition of the KPA-3 and now the 2m option board alter the effectiveness of the cooling system as designed?
> 
> Just how *heavy* is heavy?..use or perhaps abuse..?
> 
> Feeling around a radio as soon as you power down appears to me to be the same as sticking your fingers on a radiator of a car immediately after switching off. These days a lot of cars run electric fans to allow an even cool down period after running.
> 
> To make my point clearer, when I use the ride-on mower for an hour or more, I run the motor for a few minutes after I finish to effect a cooling down of the motor, I do not run my K3 (or any other radio) for RTTY then pull the power, call me cautious perhaps, but it just seems logical to me.
> 
> I hope Wayne, Eric and Lyle et al post a response in depth on this topic as many of us have differing points of view.
> 
> My two cents worth, or was that a Nickel?
> 
> Gary
> VK4WT
> K3 s/n 679
> Sent via BlackBerry® from Telstra
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