[Elecraft] [K2} K2-100 Test and Alignment Issues
John Oglesby
oglesby91 at gmail.com
Tue Jan 28 15:31:42 EST 2014
Bill - I had this exact problem on my K2/100 during testing. Changing
C1 varied the power output, but the SWR was fixed at 9.9-1. The problem
was a short between the output of the two op-amps U5A and U5B that
amplify and buffer the forward and reflected voltages before they go to
the processor. There are two resistors on the outputs that are very
close to each other and the pads were shorted so the processor saw the
same voltage for forward and reflected - ergo SWR of 9.9-1. And the
voltage varied with the C1 setting as the bridge went in and out of
balance - ergo the varying power indication. Totally a build error.
When I folded over the resistor leads, they ended up looking like they
were on a single pad. I think if you look at that area you will find
the problem.
Good Luck.
73
John
N9RE
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