[Elecraft] KPA100/KAT100 on 160 Hi Current

[Craig Rairdin]

FWIW late in the 160m contest I noticed the K2/100 was a little warm. I
switched to the current reading on my power supply and saw numbers in the
27-30 A range. I realized that a couple hours before I had cranked the power
all the way up to 111 watts (as high as it went) and hadn't turned it back
down to 100. When I turned it down to 100 the current draw looked normal
(maxing out around 20 A).

I was transmitting into an antenna that was 3:1 SWR without the KAT100; 1:1
with the tuner.

I didn't notice any bad behavior otherwise. Just thought I'd throw this into
the discussion for a data point.

Craig
NZ0R



-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of John Reiser
Sent: Thursday, December 07, 2006 9:43 AM
To: J F; Elecraft Discussion List
Subject: Re: [Elecraft] KPA100/KAT100 on 160 Hi Current


Hi Julius,

Both my K2/100s, #4970 and #5570 exhibit excessive current draw on 160 
meters, as indicated by the ammeter on my 30 watt Astron PS.  It gets up to 
27 or 28 amps.  I use a 30 amp fuse.  In every other respect, my two 
K2/100's work perfectly.  Current draw on all the other bands is less than 
20 amps.

I don't have an antenna for 160, so I never transmit on that band anyway, 
and this is not a big problem for me.  Still, being a bit of a 
perfectionist, it bothers me that it exists.

I mentioned it on the reflector a while ago.  Someone said they had the same

experience, but had no solution.  Someone else suggested that I retune the 
80 meter bandpass filter to represent a compromise between 80 and 160.  I 
tried that, but the excessive current draw continued regardless of the 
bandpass tuning.  (Could it be due to the KPA100 going into oscillation at 
the 160 frequency?)

When I saw your post, I became hopeful that it might evoke a response from 
someone who had come up with the definitive solution.  But so far there 
hasn't been any.

Good luck and 73,

John, W2GW

----- Original Message ----- 
From: "J F" <phriendly1 at yahoo.com>
To: "Elecraft Discussion List" <elecraft at mailman.qth.net>
Sent: Wednesday, December 06, 2006 5:49 AM
Subject: [Elecraft] KPA100/KAT100 on 160 Hi Current


> Well ARRL 160 is history now.
>
> As usual, with the K2 I heard more than I could get to
> hear me ;o) Evidently I heard and worked more than
> some of the local contesters with "other" brand
> equipment heheh.
>
> Anyway I have a problem... I use the KPA100 with the
> KAT100, and there may be no connection between the
> two, to stretch the bandwith of my antenna. If I set
> the K2 for 100 watts (or just twist the knob far
> clockwise), the ALC does not kick in. In a key down
> situation, the current keeps climbing until the fuse
> blows. If I set it for 99 watts (I realize this is not
> that precise) the ALC does function somewhat. I've not
> tried it with a dummy load. The antenna was fairly
> well matched (1.2:1 at it best point)and has a current
> balun on it. So this really shouldn't be happening. Do
> I have a problem with the KPA?
>
> Thanks,
>
> Julius
> n2wn
>
>
>
>
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