[Elecraft] [K2] Hi Cur questions

[Oliver Johns]

Dear folks,

I'm wondering if this is a bug, or perhaps a known feature of the  
K2.  Comments appreciated.

The following observations are made with the Max current set to 3.5  
A.  The K2 is running into a DL1 dummy load, directly connected by a  
male-male BNC adapter.  The KAT2 is not installed.  The power supply  
is rated at 4 A continuous, 6 A intermittent.  There is very little  
drop in the nominal 13.6 voltage when the Xmtr is keyed.  The BP  
filters have been aligned carefully as per the manual page 80.

On 40, 20, 17, 15, 12, 10 meters, I can set the Power knob on the K2  
to its maximum of 15.2 Watts with no sign of Hi Cur.  The actual  
current drains run somewhere around 2.5 A.  The actual power out  
varies, of course, but there is no problem with Hi Cur.  The powers  
read from the display are:  40 = 14.9   20 = 14.5   17 = 14.6   15 =  
14.1   12 = 10.9   10 = 10.0.  Notice that the power decreases on 12  
and 10, as evidently would be expected since the final is less  
efficient on these high bands.

But on 80 meters, there will be Hi Cur for any power knob setting  
above 8 Watts.  At 8 Watts, the power read from the display is 8.1  
Watts and the current drain is about 2.25 A.  But much above that and  
the current goes to the maximum and is then limited back.

And on 30 meters there will be Hi Cur for any power knob setting  
above 10 Watts.  At 10 Watts, the power read from the display is 9.8  
Watts and the current drain is 3.4 A.

The 30 meter case is particularly puzzling to me.  The BP inductors  
for 30 meters are shared with 20 meters, and the LP filter for the  
two bands is the same.  So any soldering error there would probably  
also show up on 20 meters.  And 30 meters is lower in frequency than  
20 meters and so should be more not less efficient.

I have examined, re-soldered, etc., everything in the BP and LP  
filters for 80 meters.

Any ideas, or is this just normal behavior?

Tnx,

Oliver Johns
W6ODJ