[Elecraft] KX1 Power Measurements by band

[Phil Wheeler]

DYARNES@aol.com wrote:

>Add me to the list of those experiencing low power output.  I was getting 
>under 2 watts on 40, and just over 2 watts on 30 and 20.  Gary suggested I 
>increase R30 to 27 ohms and decrease R11 to between 3.3 ohms and 5.6 ohms (after 
>first suggesting I check the toroids, etc.).  I made the above changes and my 
>power out went to about 2.5 on 40, and just over 3 watts on 30 and 20.  I had 
>been behind in monitoring the reflector, and now I see the other comments about 
>low power.  I had gathered from my exchanges with Gary that I wasn't the only 
>one with this problem.  So, I guess I will dig back in and up the value for R30 
>a bit more.  Thanks to the NorCal resistor kit, I have a nice supply.  Then, 
>hopefully, squeezing the turns on L2 will be necessary (it wasn't before 
>obviously).  My guess is, though, that I still won't get to the power levels that 
>Ron and Phil are reporting.  We'll see.
>

R30 is a bear to replace at the end, Dave -- as I found out.  It's pads 
are under the PA and close to other components (making sucking harder).  
I went for 36 ohms because that's what I found.  Forgot I have the 
NorCal resistor kit ... hmmm, but where.

With 36 ohms, I can reduce power by moving R4 a tad CCW (a touchy 
adjustment).  But I will likely leave it full CW.

I'll report on my transformer experiments (first project of the day), 
before doing the atu.

>
>I am also noticing the lack of audio output that others mentioned, although 
>on 40 it seems pretty good.  It's just on 30 and 20 that it seems a little 
>"light".  But the RX doesn't seem to miss much sensitivity wise.  Pretty darn good 
>RX design I'd say.  Everything else seems to be working like a charm!
>

Seemed like plenty of audio and signals (a contest) on 40 last night.  
By the time I resolved my 30 m problem that band was really pretty dead 
-- hope it was the band and not the rig!  Tonight I will know more based 
on 10 MHz WWV and 31 m SWBC.

In the midday yesterday there were lots of strong stations on 20 m CW 
and plenty of audio when listening to 20 m SSB.  But definitely less 
than on 40.  I do wonder if a resistor change on the LM386 might be in 
order.  A consideratioon for "later" :-)

I did get one surprise.  When going to USB the fast tuning rate is 5 
KHz.  But it starts from where you were when it was initiated.  So you 
can get  9563, 9568, etc. instead of syncing up at 9560, 9565, etc. if 
you do not initiate it at 9560 or some such.  But I've spent little time 
with the rig, so than may be a cockpit problem.

73, Phil