[Elecraft] K2 K2/100 post FD review

[Don Wilhelm]

Mike,

Congratulations on finishing the K2/100.

On the power output variation, that is not normal.
First check the voltage delivered to the K2 while in transmit.
You should do that by tapping DISPLAY and scrolling to the voltage 
display.  Your power source should provide at least 13.8 volts, but 
higher (up to 15 volts) is better.  If the voltage shown by the K2 
display during transmit is less than 12.6, make certain all power cable 
connections are tight.

If the power supply voltage is not the problem, then remove the KPA100 
from the base K2 and realign the bandpass filters.  Connect a dummy load 
to the base K2 BNC ANT jack.  After that, check the maximum power from 
the base K2 - you should have at least 10 watts on each band.  Record 
the power for each band.

Using a dummy load takes away any question about your antennas.  Always 
check into a dummy load - with an in-line wattmeter if necessary.

The other possibility is that you have a problem in the Low Pass Filter 
in the KPA100.  To check for that, re-install the KPA100, but power the 
base K2 from the coaxial power jack (no power to the KPA100 - connect 
the dummy load to the SO2339 jack on the KPA100.
Again check the maximum power on each band from the base K2.  It should 
be no more than 5% less than you found with the base K2 only.
If there is a substantial difference in power, then check the KPA100 Low 
Pass Filter - particularly checking the number of turns on the toroids.

73,
Don W3FPR


On 6/28/2020 4:04 PM, NJMike wrote:
> 
> I did notice a variation on the power output on different bands:
> 
> 80m - 100w
> 40m - 100w
> 20m - 80w
> 15m - 50w
> 10m - 30w
> 
> SWR was never above 1.3-1.
> 
> Does that sound normal?
>