[Elecraft] K3 Heat

[Guy Olinger, K2AV]

WHAT heat problem?

Currently there are over a hundred K3's I know about from all over the 
serial number range.  NO burnups, NO burnt hands. Includes one who got up 
and left it on TUNE which resulted in NO burned up K3. I'm still asking 
about what happened to the dummy load though.  NO KPA3 final failures. And 
this from a group of contesters who are notorious abusers of equipment, 
including quite some few who run the K3 at 120 watts in contests.

If the K3 was a burn-it-up item with an inherent heat design flaw, like some 
other rigs, amps, power supplies, etc, this push-everything-to-the-limits 
group would have toasted it by now.  I might have missed one, but I don't 
think so.  They DO have a LIST of other rigs, amps, power supplies, etc, 
that they HAVE turned into toast. This group is capable of toasting Alphas, 
and has.

This group meets once a month just to trade contesting gossip, experience, 
yada, yada.  One may be assured that setting a K3 on fire (or any other mode 
of heat related destruction) would have been a prime topic.  Telling stories 
on others who set things on fire in contests is such fun  : >)

One chapter has an annual "flaming balun" award just for the best of such 
delicacies.

It is for sure that Wayne is a lot more concerned about heat than any of 
them.

For myself, the K3 has the largest heat sink transfer area I've seen on a 
100 watt amplifier in an HF rig. It has by far the beefiest air flow at max 
cooling of any HF rig.  And it runs at a very quiet fan speed 1 during most 
of my operation.

What heat problem?  No heat problem.

73, Guy.

----- Original Message ----- 
From: "David Wilburn" <dave.wilburn at verizon.net>
To: "Elecraft Discussion List" <elecraft at mailman.qth.net>
Sent: Thursday, May 14, 2009 9:00 PM
Subject: Re: [Elecraft] K3 Heat


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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