[Elecraft] K1 on 12/10m (was: 10 meters on K1 - component values)

[Akinori Harry SHIBATA]

Hi, all.

I built my KFL1-2 as a 12m/10m board.

I thank Stephanie VA3UXB for his suggestions on component values.

Values of components I used are as follows:

Band 1: 24.8MHz
  C1, C5   - 100
  C2, C4   - 47
  C3       - 1
  C11, C15 - 270
  C12, C14 - 33
  C13      - 2
  C21, C23 - 68
  C22      - 150
  L9, L10  - 0.26uH (T37-6 yellow core; 8turns, 16cm)
  X1       - 32.8000MHz (fundamental)

Band 2: 28.0MHz
  C6, C10  - 82
  C7, C9   - 47
  C8       - 1
  C16, C20 - 220
  C17, C19 - 33
  C18      - 2
  C24, C26 - 68
  C25      - 150
  L11, L12 - 0.26uH (T37-6 yellow core; 8turns, 16cm)
  X2       - 36.0000MHz (fundamental)

Additional modifications as Stephanie did:

On Sun, 1 Jan 2006 12:57:13 -0500,
Stephanie Maks <va3uxb at maksystems.com> wrote:
>Subject: [Elecraft] 10 meters on K1 - component values

>#1:  220pf capacitor added to filter board, on the top side, on P2  
>between pins 7 and 8.  This could also be done on the RF board, at  
>pins 7 & 8 of J7.  I had more clearance though on the filter board.
>
>#2:  On the RF board, R11 has been changed from 82 ohms to 33 ohms,  
>to increase the gain of the Buffer.

I added 56-ohm in parallel with R11 (82 ohms).

>#3:  On the RF board, T3's turns have been compressed as tight as  
>possible.  The windings now occupy about 130 degrees of the core.   
>Experimentation showed that the tighter the windings, the higher the  
>output on 10 meters.  This did not seem to affect the other bands at  
>all, i.e. no noticable effect even down at 80 M.  Next time I feel  
>like experimenting, I might try rewinding T3 to make it even tighter.

In additon to above mods, I added a 0.001uF capacitor in parallel 
with R30 on the RF board.

My K1 got the output power as follows:
  24MHz = 7+ watts @ 13.8V
  28MHz = 4 watts @ 13.8V


VFO range must be "150kHz", not "80kHz".  The 12-meter begins from 
24.890MHz but K1 covers this band starting 24.800MHz.


Best Regards,

harry
--
Akinori Harry SHIBATA, JL3AMK http://jl3amk.net/ http://jl3amk.org/
Elecraft K1/Mod (160-10m CW 5W) & KX1 (40-20m CW 4W) + Whip Antenna
A1C#311 FISTS#15002 G-QRP#11804 NAQCC#540 QRP-ARCI#12260 RU-QRP#110