[Elecraft] KPA100 problem?

[Dan Holloway]

Hello,

While testing my new KPA100, I have encountered several symptoms that make
me wonder if �t has a problem:

1.  KPA100 manual, page 45, Power Supply Test, step 6 states: with only the
high-current supply on, the K2 should remain off (it does).
However, contrary to page 46, Power Supply Test, step 10, my K2 requires
that the low-current supply be connected and on inorder to turn on the K2
and perform the "Fan Test" on page 46.

2.  Page 45, Power Supply Test, step 9:  The K2's display indicates 12.7V
(low-current supply = 13.13V) and I = 0.36A.  Doesn't the K2's display only
indicate voltage after K2-D10's drop and current drawn by the K2 from the
low-current supply?
The high-current supply = 12.78V; I am puzzled at how the K2's voltage
display allows me to determine the drop across KPA100-D9.

3.  Bias current adjustment (fan = nor; R6 fully CCW).  Page 47, Bias
Current Adjustment, step 5:  With power set to 0.1W, I measure only 0.002A
(2 ma. vs. an expected 200 - 400 ma.) on the high-current lead.  In step 6,
power set to 11W, current increases to only 0.136A (136 ma); the fan remains
off , not at low speed.  The fan tests, performed earlier, were normal.
Are these currents too low?  Entering the menu, turning the fan on to low or
high speed causes no change in the above currents.

After reading Ed Muns', W0YK, posting  (PA Bias Adjustment Step) on Nov 26,
2002, I'm still puzzled.  Ed states that "the base K2 draws 200-400 ma. (as
does mine) in receive mode"(but that's not how I read the manual).  Am I
mis-interpreting the KPA100's manual (see item 3 above) in thinking the
high-current power supply should be drawing 200-400 ma?  The low-current
supply is definitely drawing 200-400 ma. (about 360 ma. as my K2 is
presently configured with the KPA100 connected) and I now suspect that the 2
ma. or 136ma. that I measure on the high-current supply is correct.  Is 136
ma. now my target and do I now adjust R6 for 536 ma.,  plus 50 ma. for the
fan, if it turns on?

I admit that I'm not certain whether my KPA100 has a problem or if it is my
interpretation of the manual.  At this stage, I assume that the currents on
the low and high-current supplies are quite separate and both must be added
to find the total current drawn.

Any assistance will be greatly appreciated.

Dan
VK8AN (K6KMD)
K2/100 #2469