[Elecraft] Three Questions?

[Tom Hammond NØSS]

>1. Is there a way to "turn off" the KAT2, in case one would want to use an 
>external tuner?

Sure.  MENU | ATU | CAL P (or CAL S)  should do it.

>2. How many mods for SSB are actually recommended by Elecraft?

The 2nd Xfil SSB Mod certainly is.

Other mods not necessarily 'recommended', but probably worthwhile to consider:

   If you have marginal-to-low mic gain, change KSB2-R14 from 1K to 10K.
   ___

   Here's a mod from KI6WX which helps flatten the response of the
   2nd Xfil a bit more. I have installed it in my K2 and it has
   produced a somewhat flatter passband when using my OP1 filter
   on SSB receive.

   Quoting KI6WX:

   The change may be installed with the following steps:

   1. Install the 2nd Xfil Mod described in
   http://www.elecraft.com/Apps/new_fil_docs/k2_2nd_xfil_ssb_mod.pdf

   2. Replace the 120pF capacitor in the above mod with a 100pF
   capacitor

   3. Install a 5.6k resistor from pin 1 of U11 to pin 2 of U11 on
   the RF board

   4. Check the adjustment of L34. In CW mode, tune to the weak
   birdie heard at 7 MHz. Set the filter bandwidth to 0.1 kHz and
   tune L34 for maximum signal relative to the background noise.

   Your K2 now has a much flatter response when receiving SSB
   signals through the OP1 filter.

>3. This is a repeat. Exactly what is the recommended voltage, etc. for 
>keeping the internal battery charged in the K2?

14.1 to 14.3 VDC. 14.3 VDC is probably the better choice.

73,

Tom Hammond   N0SS