[Elecraft] K2 - Protect those Finals

[Ron D'Eau Claire]

John, I'm an O.T. who always had a spare final "bottle" for my rigs. Moving
to transistors didn't change a thing since in the 1970's and 80's my
homebrew rigs were squeezing a few watts out of a transistor rated for
perhaps 1/2 watt dissipation so it was common to have to quickly swap a
smoking final for a good one, HI! 

With that experience, when I built my K2 in 2000 I routinely ordered a spare
set of finals against the day they would be needed. 

A decade and countless QSOs later the replacement finals are still sitting
in the envelope they arrived in. 

Wayne designs robust rigs. It's hard to damage them, including the finals.

Don mentioned one possible way to overstress the finals by feeding a too-low
impedance load that can fool the power control circuit. In any rig, solid
state or vacuum tube, it's prudent to match the load to the finals. That's
why we have ATUs. IMX, the K2 can take full power key-down transmission into
hugely mismatched loads for at least long enough to realize that something
is very wrong.  

Another prudent approach is to avoid pushing the rig beyond its rated power.
The K2 will make excess power on most bands. That was intentional to ensure
it made its *rated* power on all bands. But some operators are of the "all
knobs right" class who feel that every watt must be squeezed out of the rig.
While Elecraft rigs will generally take such punishment, under those
conditions they are far less tolerant of mistakes such as transmitting into
a high SWR load. 

73, Ron AC7AC

-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of John
Sent: Saturday, April 21, 2012 9:45 AM
To: Elecraft at mailman.qth.net
Subject: [Elecraft] K2 - Protect those Finals

K2 Folks,

After monitoring this list for quite a while and knowing a few locals who
use or used the K2, the topic of damaged finals comes up often.

I especially took note of a post highlighting the KAT2 has a "real" 
power meter which, I suppose, augments the stock power output control
loop... right?

This brings up a simple question.

If I order the K2, is ordering and installing the KAT2 a smart move that
will reduce the chance of damaging the finals?

Thanks.

John, kx4o
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