K2-R schematic with 6AN8 extracted by Achim Dassow. The output tube is a probably 6AN8 triode pentode. Another version of the K2-R used a 6X8, as pointed out by Bob Pease in the RS power supply. (9-14-8)

The K2-R can also be found in the RK-200 power supply, as pointed out by Achim Dassow.

Bob Pease clarifies the two versions of the K2-R in an email to me and Achim Dassow:------------------------------------------------------------

Date: Thu, 14 Aug 2008 13:25:42

Hello  to  Joe  and  Achim, 

Here  are the  schematic  and  notes  on the  Model RS.  Not to be confused  with the SR-400 or  R-300  or  R-500 (or the  6033 or the PR-15-150  or  PR-300 at lower  voltages.)  Copied  from an old 1955 Mimeographed Data Sheet. Now  just over  53  years old.

Aha.  The 6X8  is  very  similar  to the  6AN8 but in a 9-pin  bottle, it has  a  SEPARATE  pin  ( pin 1) so you can bias  the Suppressor Grid  separate  from the Cathode.  And  the  cathode is common  to both  the  triode  and  the  pentode,  at  pin 6.   See at: http://www.nj7p.org/Tube4.php?tube=6X8

The 6AN8 has  separate  connections  to the two  cathodes at pins 3  and 9,  and  the suppressor  grid is  tied  internally to pin 9.   The K2-R  for  which you  drew the  schematic  is  designed  to go with the 6AN8  and   NOT  with the 6X8.  So at one time  there  may have been  TWO  different versions of  K2-R,  one  compatible  only  with the 6X8, and  the other  only with 6AN8.

Have  fun!!    /  Best  regards. / rap