[Elecraft] K2 with FT8 at .1 Watt of Power

[Don Wilhelm]

Denny,

If you have the base K2 only, then it is likely accurate, even more so 
with the KAT2.

I repaired a lot of K2s, but never thought to measure the accuracy at 
those low power levels even though I do have accurate low power 
measuring tools.  The major limiting factor will be the forward voltage 
drop of the 1N5711 diodes.

If you have an oscilloscope with a 10X probe and a 50 ohm dummy load, 
you can check your own K2.  Measure the RF voltage across the dummy 
load.  Power = Vp-p squared divided by 400 for a 50 ohm load. (the 
'scope will display the peak to peak voltage, no need to go through a 
lot of conversions.

73,
Don W3FPR

On 8/26/2020 3:02 PM, Wb9msm wrote:
> Hi All -
> 
> I am really enjoying my K2/100 very much.  It really is a nice radio.  I
> recently got my WAS endorsement sticker for QRP.  It was a great time
> chasing the states around the bands.  I operated my K2 in the range of 4.5
> Watts.  There was a bit of power creep up and down from that but minimal at
> best.  Just the other night I decided to try making contacts on FT8 with
> only .1 Watt(100 milliwatts)  and was really impressed that I was making
> contacts with that low of power.  I do not have an actual wattmeter that
> will measure that low of power.  Can anyone tell me if the .1 Watt setting
> on the K2 is in the ballpark of that amount of power.  This radio really has
> been impressing me with all of its capabilities.  I am continually amazed at
> what it does!  I am using an old RigBlaster which interfaces with my ACER
> Aspire perfectly for FT8.  I could not be happier to say the least. If
> anyone can share their experience with this power output question I have I
> would appreciate your comments.  Thanks and 73,  Denny WB9MSM  P.S. I am
> thinking of going for QRPp WAS.