[Elecraft] No RF on TUNE - K2 Alignment

Woody [email protected]
Sun Apr 28 10:05:01 2002


Hello All,

I am in the process of putting my K2 together and ran into a problem
and need some advice... 

Assembly & Test went well until Page 72 -Alignment/Test
III - 40M align.  When went to TUNE, got no RF out.  Below is a list
of symptoms and observations.   Also , there are three links to jpg
images of schematics (segments of) with voltage readings.

Can you suggest corrective action?  Any comments welcome!

1)  Hearing Rx signals on 80M, 40M, and 15M.  Only a *very* low level
white noise on other bands.  (NOTE: Pre final alignment, FWIW) 

2) TP2 - BFO test, pg 59 -  4913 kHz present in FCTR mode.
  
2a) NOTE:  Monitoring TP2 with scope, signal goes away when leaving
FCTR
mode (to Rx frq DISPLAY).  
TP2 signal not present during tune (by scope). See item 5...  

3) Power control (Not in Tune, but normal Display) is stable and
easily set to "2".  When in TUNE, unstable reading - jumping between
14 -17.

4) S- meter working OK in Rx.  When in TUNE, highest bar lit
continuously while lower bars flashing from Zero -> up randomly - like
noisy.

The following observations are denoted on schematic segment links
below...

5) TUNE or Rx:  No +V on drain of Q24 (V ALC)

6) V RFDET goes to just over 5 volts when TUNE actuated (AUX I/O - 10)
-No RF out.

****More detailed voltage measurements are shown on the schematic
segments.  HELP!

Control board:
http://woodycache.home.att.net/control.jpg

RF board 1: 
http://woodycache.home.att.net/rf2.jpg

RF board 2:
http://woodycache.home.att.net/rf3.jpg

Thanks Much!
Woody, WB4QXE
-- 
My website: http://woody.white.home.att.net/
WB4QXE - Homebrew Ham/Electronics Projects & 
eclectic Scanning Electron Microscope Images