[Elecraft] KX-1 S-meter calibration?

[Don Wilhelm]

Mike,

To set the KX1 S-meter, first select DISPLAY so the S-meter bars are 
displayed.  Apply no signal for at least 30 seconds to let the capacitor 
discharge.
Then enter the menu for SIG - turn the VFO knob to set the low value.  
Start with a value of 78, then reduce it 2 numbers at a time until all 
the bars go out - now increase it by 1 and see if there are still no 
bars displayed - if so, leave it there, but if there is one bar 
illuminated (even dimly), reduce the menu number by 1 and leave it there.

If you have a signal generator that can produce a known S-9 (-73 dBm or 
50 uV) signal, connect it to the antenna jack and tune that signal on 
the KX1.  Set the KX1 for DISPLAY if it is not still in that mode and 
check the number of bars displayed.  If it is 5, that is correct.  If 
not 5, enter the menu and using the right two blue buttons, increase or 
decrease the single digit number shown.  A lower number should increase 
the number of bars illuminated while a higher number will decrease the 
number of bars.
If you have no generator, set the single digit number to 3.

If the S-meter still does not work, then check the AGC circuit.  Check 
D4 for proper orientation and check R5, R20 C53, C8 and Q9 for correct 
values and good soldering (re-flow the soldering with a hot iron - 750 
deg/F - and add just a touch of new flux).  Do you have Q9 in properly - 
the flat side should be facing away from the KX1 board - same for Q2 and Q3.

73,
Don W3FPR

Mike M wrote:
> All -
>
> I completed my KX-1 last week (still trying to make a QSO) and
> everything seems to be working properly, but I can't seem to calibrate
> the S meter.  I can get it to show two bars constantly, zero bars
> constantly, or two flashing bars constantly.  There is no change in
> bars regardless of how strong a signal it receives.
>
> I don't know if there is a hardware problem, or I just don't
> understand how to do the calibration.  Any hints?  Thanks.
>
> 73,
> Mike, KL7MJ
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