[Elecraft] help on alignment and test, part II

[W3FPR - Don Wilhelm]

LLoyd,

How old is your K2 kit?  Take a look at the MPS5179s on the Control Board at
Q9 and Q10 - if they are blue (rather than black), they are the cause of
your problem.  Elecraft will supply replacements for you if they are the
blue-faced ones.  In the meantime, you can use 2N2222s in their place if you
want to get up and running quickly (borrow the 2 2N2222s from the later part
of the RF board aseembly).

Other than the above 2N5179 problem or an improperly constructed counter
probe, I can't think of any reason you should not see proper readings on the
CAL FCTR display.  Check the connection of your probe to the Control Board -
the shield should be closest to the left side panel - should you have it
backwards, it will behave as you have described.

73,
Don W3FPR

> -----Original Message-----
>
>  OK, I got to p.60. Plugged in the freq. probe, got it
> to TP3, did the CAL thing, and got 0000.00. Tried to
> measure with my DMM's freq counter with that still
> connected...and while doing this, the K2 read about
> 10.96 something, changing rapidly. Disconnected the
> DMM from TP#, the K2 read 00000.00 again. The DMM,
> meanwhile, read 12.01 at TP3.
>
>   I tried the VCO test at TP1, got 0000.00. Went to
> troubleshooting, using my RF probe, checked the
> Reference Oscillator output, got 0.767 Vrms. VCO
> output = 0.418 Vrms. VCO Buffer output = 0.677 Vrms.
> All seemed good!
>
>   TP2 showed something, didn't write it down, but it
> was, like, 4912 or something...showed my
> carefully-built probe was working, I suppose.
>
>
>   Then I checked some voltages, and found some wacky
> stuff. On U4, pin 5 was zero. pin 7 was 5V. pin 8
> showed rapid variation. Others were ok.
>
>   On U5, pin 1 was 5V, and pin 2 was zero V!!! others
> were ok. Yow!
>
>    on U1, pins 9 and 10 showed rapid variation, others
> were ok. U2, U3, U6, U8, U11 and U12 were all ok.
>
>   Q17 had a D of 1.637, others ok. Q18 had S of 1.615
> and D of 7.92.
>
>    That's all I had time to check...hopefully, it's
> enough for someone to suggest what to look for.
>
>   Thanks!
>
>    LL/K3ESE
>