[Elecraft] Low BFO Output

[Tedd Wong]

First some history.  During the BFO test, I discovered my BFO range was low.  My upper frequency was 4917.55 and lower frequency was 4914.26.  After much consultation with Gary, I tried the various tricks such as padding C174 and C173, adding caps to the junction of X3 and X4, and even adding turns to L33.  After much prodding I finally got the range from 4917.55 to 4912.60.  So far so good.  I also got my filters aligned with Spectrogram which proved to be very easy.    Then I noticed my receiver sensitivity appeared to be very low.  (Even worse than my ICOM 706.  Now that's bad!)  Out came the XG2 to perform some MDS tests.  Following the directions from the XG2 manual for setting up the K2, inputting 1 uV, and with the AF gain at maximum, I measure .009 volts at the speaker terminals. With no input I can't even get a reading.  (Kinda hard to divide by zero.)  This led me to the signal tracing portion on the manual.  I got as far as the BFO output measurement and there I r!
 an into the problem of a very low BFO output to U6 pin 1.  The manual states .20 to .70 Vrms and I get .05 Vrms with my RF probe.  Could my super stiff crystals be the cause of such low output?  Perhaps I tried bending the crystals too much?  Would a low BFO output cause such low receiver sensitivity?  Are there some other components to suspect other than the crystals?  Incidently Elecraft is sending me another set of BFO crystals, gratis, to hopefully cure my BFO range problem without padding.  Thanks for reading.  Merry Christmas and Happy New Year to all Elecrafters.

Tedd K6OI