[Elecraft] K2 receive volume

[Bill Tippett]

ZL1TW wrote:
 >I have read the thread about the lack of volume in the K2 that some chaps 
have reported, and personally I find it hard to imagine any problem in that 
area.

         I agree Ron.  On my #4119, normal AF Gain into both
a Heil Pro-set and Radio Shack PRO-50MX is at 9 o'clock and
normal for the internal speaker is at 10 o'clock.  12 o'clock on
both is quite uncomfortable to my ears with either headphones
or the internal speaker.  Max at 5 o'clock is actually near the
threshold of pain using headphone and sounds like it may be
near the distortion point for the internal speaker.

         Perhaps there are some differences in how our AGC
Threshold is set.  Mine is set to 3.70 volts versus the 3.80
default suggested in Elecraft's alignment procedure.  I set
mine using #1 in the following application note:

http://www.elecraft.com/Apps/RX_Gain_application_note.htm


1. If the AGC circuit is limiting the receiver's output even on very 
low-level signals, you can change the resting AGC threshold. First, switch 
to a band that has VERY low atmospheric noise (and no indication on the 
S-meter). Then turn the AGC OFF (by holding the PRE/ATT and AGC buttons 
together). If the noise is significantly louder when AGC is OFF, the K2 may 
be turning on the AGC too quickly. The threshold can be changed by making 
R1 on the control board smaller. Try putting in a pot at R1 and see where 
you need to set it to get the AGC threshold you prefer. The value should 
not be reduced by more than about 30%. If you choose a new resistor, you'll 
have to reset CAL S HI and CAL S LO to recalibrate the S-meter, and the 
numbers for S HI and S LO will be very different from the defaults. Values 
of R1 that are too small may result in an inability to set up the S-meter 
correctly.

                                 73,  Bill  W4ZV