KX-1 S-meter calibration?

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KX-1 S-meter calibration?

Mike M-4
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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Re: KX-1 S-meter calibration?

Don Wilhelm-4
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
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>  
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Re: KX-1 S-meter calibration?

Mike M-4
Don -
Thanks!  That works. I didn't really understand what the manual was
saying, and I was overcorrecting.

73,
Mike, KL7MJ
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