[Elecraft] K2 Over Current High Power 40 Meters.

[Don Wilhelm]

Johnny,

You have a Power Control problem - alignment is not going to fix it, and 
you will have to correct it and have proper power control before any of 
the alignment results make sense.

Since you indicate that the problem exists with only the base K2, that 
is the place to start troubleshooting.  Do not connect the KPA100 - it 
must be physically removed.

Set the power to about 2 watts, but monitor the actual power with an 
external wattmeter and drive a dummy load.
Then do a TUNE while monitoring the VRFDET signal.  It is easiest to 
probe at Control Board P4 pin 10.  Limit the time for a TUNE to 15 to 20 
seconds if the actual power is going to maximum (it may be as high as 19 
watts).
If the DC voltage on VRFDET is near zero, the RF Detector is not working 
for some reason - replace RF Board D19 and try again.  If still no 
voltage on VRFDET, reflow the soldering on RF board R66, R67, R68, R69 
and C77.

Should you find a DC voltage that is above 3.5 volts, D19 is working 
fine, but the MCU is not responding.  The most likely problem is that 
the MCU (Control Board U6) has a damaged input at pin 2.  In that case, 
it has to be replaced.
Here things may get a little complicated depending on the level of your 
current MCU.  If it is 2.04P or 2.04r, you can order FW-K2MCU and simply 
replace U6.  If it is less than that, you must order FW-K2MCIO and 
replace both CB U6 and RF Board U1.

So hope the problem is D19, that is inexpensive, but the firmware is 
expensive.

73,
Don W3FPR

On 5/28/2019 7:39 AM, Johnny Matlock wrote:
> Gm Group
> I connected a newly acquitted “twin” Amp and Tuner in a separate enclosure
> setup this weekend.
> 
> While bench testing with a dummy load  I noticed that I would get high a
> current message if the power setting was turned over midway, and the amp
> was trying to produce more than 100 watts!
> 
> 
> I disconnected the Amp and Tuner, continued to test the bare K2.
> 
> On 40 meters my power setting  wasn’t tracking the actual output.
> The actual power out was a lot higher than the radio’s setting.
> 
> I downloaded the calibration instructions and continued testing.
> 
> When I Set the power to 2 watts and attempt to peak the 40 meter coils,
> The power goes up to over 10 watts?
> 
> I pulled the lids and looked at the connections around the 40 meter coils,
> also I did a reflow on the connections in that area.
> 
> 
> I’m trying to understand the cal instructions?
> 
> If you set the control at 2 watts and peak the two coils, and the power is
> higher, how will it track accurately?
> 
> I’m trying to decide if I have a problem
> With my Radio, or am I just not understanding the calibration instructions??
> 
> I went to Don’s website and downloaded his condensed instructions, but I
> was too tired to give them a try!!
>