K2 #7446 is alive and made my first QSO

[Stan AE7UT]

Just finished aligning my K2 last night.
Made a nice QSO 1,000 miles away on 5 watts.
It was great getting a 599 report on my new K2.

One thing that seems a little different is the volume I'm getting.
I have a K2 someone else build that is fully loaded.  It is much louder
on receive than this one.  I have the RF gain all the way up and the AF
gain 3/4 of the way up to get a good volume.
Is that normal for a "base" K2?

73
Stan AE7UT

[Don Wilhelm-4]

Stan,

That is *not* normal unless the bands are totally dead and there is
little atmospheric noise.
You should easily hear the receiver internal noise with that high AF
gain setting.  A normal AF gain setting is a 9 to 11 o'clock position.

Take a look at transformer T7 - the red winding should be closest to U12
- it is sometimes mounted backwards.
Double check the position of the D40 and D41 diodes soldered on the
bottom of the RF board.

If those checks do not reveal anything incorrect, you may have to do
some Receive Signal Tracing as detailed in Appendix E of the manual.  
For that, you will need a strong signal generator - the XG3 set for 0
dBm is greater than the 0.14 volts input asked for by the manual, so a
potentiometer (200 to 500 ohms) across the generator may be necessary,
or use a 3 dB attenuator.
If you do not have the XG3 or other suitable RF generator, you can build
the simple crystal oscillator from the circuit shown in the manual.

Note when Signal Tracing, when you get to the check at the output of
U12, you will not be able to achieve that saturation level unless you
lift one end of the D40 and D41 diode pair.  The 'expected values' in
the manual were generated before those diodes were added to the design.

73,
Don W3FPR

On 7/20/2013 2:33 PM, Stan AE7UT wrote:

> Just finished aligning my K2 last night.
> Made a nice QSO 1,000 miles away on 5 watts.
> It was great getting a 599 report on my new K2.
>
> One thing that seems a little different is the volume I'm getting.
> I have a K2 someone else build that is fully loaded.  It is much louder
> on receive than this one.  I have the RF gain all the way up and the AF
> gain 3/4 of the way up to get a good volume.
> Is that normal for a "base" K2?
>

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[ok1rr]

Just finished the assembly but there is no RX output. There is noise,
DSP and filters seems OK but no signal, sometimes birdies. It seems like
a receiver without VFO signal. Any ideas?

73,
Martin, OK1RR
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[Mike K8CN]

Martin,

I presume you have also finished building a K2 since you posted in response to Stan, AE7UT's earlier comment about his K2's receive sensitivity?

Did you perform all of the preliminary alignment steps in the "Alignment and Test, Part II" that should yield a working 40 meter receiver?

Please clarify where you are in the overall test procedures for the K2.

Thanks, and 73,
Mike, K8CN

[Stan AE7UT]

Don thanks so much for your quick reply and help.
I went through all your suggestions and all looked great.
I then looked in Appendix E as you suggested and went through those steps.

Under problem #100 it says to check for missing audio filter options or the bypass jumpers.
I re-soldered the jumpers and all is well.  Very loud audio now even seems better than my other K2.

Now on to the filter alignment.  I build an Elecraft wide band noise generator last night and I'm looking forward to learning how to get those filters set up.

Thanks so much.

73
Stan AE7UT

[Don Wilhelm-4]

Stan,

If you have not already, check out the K2 Dial Calibration article on my
website.  Part 3 covers the filters.
If you need a copy of Spectrogram, look for a link near the bottom of my
home page.

73,
Don W3FPR

On 7/21/2013 3:22 AM, Stan AE7UT wrote:

> Don thanks so much for your quick reply and help.
> I went through all your suggestions and all looked great.
> I then looked in Appendix E as you suggested and went through those steps.
>
> Under problem #100 it says to check for missing audio filter options or the
> bypass jumpers.
> I re-soldered the jumpers and all is well.  Very loud audio now even seems
> better than my other K2.
>
> Now on to the filter alignment.  I build an Elecraft wide band noise
> generator last night and I'm looking forward to learning how to get those
> filters set up.
>
> Thanks so much.
>
> 73
> Stan AE7UT
>
>
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/K2-7446-is-alive-and-made-my-first-QSO-tp7576940p7576953.html
> Sent from the Elecraft mailing list archive at Nabble.com.
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>
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> Please help support this email list: http://www.qsl.net/donate.html
>

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[Stan AE7UT]

Thanks for the links and your great web site Don.
I got it all dialed in last night and it's working FB.
Made another CW contact to the East Coast so transmit is working great.
The receive seems as good as my K3 if not better.

73
Stan AE7UT