S-meter alignment

[Evert Bakker (PA2KW)]

Hi all,

May be I'm to critical but lets try once more. After finishing the AGC
Threshold setting, the next alignment is the S-meter. When completing
the last CAL-S-HI step, and setting the RF Gain potentiometer back to
full CCW, only led nr. 9 lits and not nr 10. Trying to correct this I
pressed the menu button and immediately led nr 9 goes off and led nr. 8
lits (Huh??). Rotating the VFO knob to search for the CAL mode, led nr 8
switched off and led nr 10 comes on again.



To be short, I tried many times to get the required result but there
seems to be an instability somewhere in the circuit. I checked the
supply voltage (13.8V) and the two regulators on the Control Board to
see if they were producing accesive noise at the outputs, but they
looked ok (less than 2 mV noise and limited by the scoop, Tek 2465B).

Has anybody out there a slightest idea what I'm doing wrong (or even worse)?

Evert, PA2KW

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[Don Wilhelm-3]

Evert,

I don't think you are doing anything wrong - but the input circuit that
drive the AGC mixer is not yet constructed, and the open signal line may
just be picking up local noise.

The best advice I can give on the S-meter alignment is - Just set it
approximately now, then re-do it after completing the receiver (next
assembly process).  I too have observed that it seems a bit unstable at the
point of construction where you are insructed to set it.  While this place
in the manual is the best place to become familiar with the menu items, I do
not believe it is the best place for 'final' adjustments - better to wait
until you have the K2 completed and then repeat the settings for AGC
Threshold, CAL S Lo and CAL S Hi.

73,
Don W3FPR

> -----Original Message-----
>
> May be I'm to critical but lets try once more. After finishing the AGC
> Threshold setting, the next alignment is the S-meter. When completing
> the last CAL-S-HI step, and setting the RF Gain potentiometer back to
> full CCW, only led nr. 9 lits and not nr 10. Trying to correct this I
> pressed the menu button and immediately led nr 9 goes off and led nr. 8
> lits (Huh??). Rotating the VFO knob to search for the CAL mode, led nr 8
> switched off and led nr 10 comes on again.
>
>
>
> To be short, I tried many times to get the required result but there
> seems to be an instability somewhere in the circuit. I checked the
> supply voltage (13.8V) and the two regulators on the Control Board to
> see if they were producing accesive noise at the outputs, but they
> looked ok (less than 2 mV noise and limited by the scoop, Tek 2465B).
>
> Has anybody out there a slightest idea what I'm doing wrong (or
> even worse)?
>
> Evert, PA2KW
>
>

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