[Elecraft] No ears , k2#5315

[Don Wilhelm]

Roger,

If the S-meter is lively, most likely the stages through the IF amplifier
are probably good.  Be certain you see an increase in the S-meter when the
Pre-Amp is turned on and a decrease when the Attenuator is turned on -
expect about a 1 or 2 LED bar difference in both cases.  Your voltage at the
AGC Threshold of 3.78 volts is not an indicator of a problem at this point.

Did you pre-set the BFO frequencies to the values shown on page 89?  If not,
that alone may be your problem.

If you have set the BFOs and still have inadequate audio, the problem can be
in the 2nd Xtal Filter, or the Product Detector, or the Mute or AF Amp
stages.  Check the DC voltages for these stages and compare to the DC
voltage chart in Appendix F as a first step - you should measure DC Voltages
within 10% of the value shown in the chart.

If the DC Voltages are OK, check all the signal paths from the 2nd Xtal
Filter through the AF Amp for good solder connections - the signal paths
include all 3 boards and their connectors because the AF Gain control is
located on the Front Panel.  Use the schematic as a guide in identifying the
signal paths.

The sidetone is injected into the audio amp IC at a separate pin from the
audio, so that indicates only that the Audio IC is capable of producing some
sound.

73,
Don W3FPR

> -----Original Message-----
>
> I'm building K2 #5315, everything went well upto page 64 where I
> should do
> the IF amplifier alignment.
> It appears that there is no audio at all ( beter say very very weak ).
> I cheked the earphones by hitting the SPOT , which was ok.
> But I can not hear the 7000 internal signal at all.
>
> When I tune my VFO there is definitely a signal  and the S-meter
> runs very
> well, especially above  7100 where all of those commercial staions are.
>
> Checked the agc  . I got 3.78 V on U2 pin 5 , that is fully CCW R1.
> AF gain pot is approx 5 k , Rp6 (7-8 ) is 5K , R1 is 50K
>
> checked 8R , D6 is 7.73 V and D7 is 0 V
>
> All looks ok , anyone any suggestion ?
>
> Cheers
> Roger
> OE6MSF
>
>