[Elecraft] K3 power out issue

[Bruce Meier]

Update – 

 

Not sure how I missed this, but I just determined that this ONLY happens
when NOT in SPLIT mode.   And – it happens on BOTH K3s.  I had my other K3
in split and did not notice it.  I can reproduce the same symptom on both
K3s when NOT in split but -  when in split – both are fine.  Doesn’t matter
what band nor does it matter if VFO A and B are on the same or different
frequencies.

 

When NOT in SPLIT the output power overshoots for the first 3 dahs every
time the power level is changed either up or down.

 

Hummmmm,

 

Bruce – N1LN

 

From: Bruce Meier [mailto:bemeier at bellsouth.net] 
Sent: Monday, April 08, 2013 20:06
To: 'elecraft at mailman.qth.net'
Subject: K3 power out issue

 

I just noticed that one of my K3s seems to have a power out issue.
Specifically, when keying for the first time, the output power seems to be
overshooting what it is set at.   If I continue to send CW at the same power
it is fine.   If I decrease or increase the power the output overshoots what
it is set at and them comes back down.  If I change bands, even without
changing the power level, the power overshoots the power selected for the
first few dahs.

 

How do I know this?  Well, the configuration is a K3/100 and an Acom 2000A.
The Acom forward power LEDs overshoot the 1500 watt limit and then come back
down.  It should take roughly 50w to drive the Acom to legal limit.
However, if I set the power on the K3 to 45 the Acom reads 1600 and then
drops to 1400 on the third dah.  If I set the K3 to 50 watts the Acom reads
1800 and then drops to 1500 on the third dah.   This suspect K3 used to have
an Ameritron AL1500 connected to it so this issue could have been occurring
for some time and I would not have known it.

 

So – you say – why do I suspect the K3?  Well, I have (2) K3/100s and (2)
Acom 2000As and the ONLY time this happens is if either Acom is connected to
the suspect K3.  The other K3 when connected to either Acom is just fine.
The power reading on the Acom connected to the “good” K3 is as it should be
– constant.  Additionally, the power output reading on the K3 RF power scale
overshoots the selected power and then comes back down to the power
selected.  It is just not as noticeable as the Acom RED Leds.

 

I went through all the memory settings on both K3s and they are identical.
I did calibrations on both K3s at 5w and 50w and the problem stays with the
suspect K3.  

 

Both K3s are at the following uCode levels:    4.60 / d1 = 2.8 / d2 = 2.8 /
FL 1.15

Ø  Yes, I did a u-code reload

 

Both K3s have all the same updates installed

The suspect K3 is serial number:  1193

The working K3 is serial number: 1062

 

 

Anyone have any suggestions?

 

Thanks and 73,

 

Bruce – N1LN