[Elecraft] K2/100 #4684

[R. Kevin Stover]

Hi all.

I've completed test and alignment part II but have found a few worrisome 
things.
All of the resistance checks except RF board U6, pin 8, to ground are 
where they are supposed to be.
U6, pin 8 measures about 48 Ohms, much less than it should be.

When I do the test and alignment I get these numbers.

PLL Oscillator Range - 9.81 kHz

VCO voltage readings.
3500  2.16   4000  6.00
7000  1.61  7300  3.16
10K   2.64   10.15K  3.13
14K   2.42   15K   4.05
21K   2.12    21.45K  3.14
24.8K  4.00   25K   4.38
28K    3.37    28.8K   4.23

BFO High Freq   4917.13
BFO Low Freq   4912.43
Range   4.70 kHz

BFO Alignment goes well and set to the book bandwidth and BFO figures.

VFO Linearization passes.

I.F. Amplifier Alignment takes between 1.75 and 2 turns down into L34.

40m Band pass Filter Alignment. This is where things get strange.
I hear no rise in signal/noise when I connect the antenna and I need to 
really crank the AF gain up to hear anything through 8 Ohm headphones.
L1 and L2 are down almost to the stops in their cans. I can't discern 
any real peak in signal.

Your input would be appreciated as to the cause of the low U6, pin8 
reading and the other problems.

Thanks for your input.

-- 
R. Kevin Stover
AC0H