[Elecraft] K1 deaf after KNB1 installation

[Byron Servies]

On Dec 25, 2009, at 2:14 PM, Mike Morrow wrote:

> Seriously, though, I'll assume that you had to install the RF board J1
> connector as part of your KNB1 installation process.  In other words,
> the J1 connector was not in place earlier when your K1 was working.

This occurred to me on the way to a Christmas Eve party and I kept it in mind but took a some time off from the problem to enjoy Christmas.

After carefully inspecting all the parts for bridges today, cleaning up a few flux spots, etc., and taking some high resolution photos with a macro lens and my D200 (ala QST) I thought I would have to go the RF probe route.  I re-installed the KNB1 and KAT1 to wait for tomorrow.

The football was so bad tonight, however, I decided to take another look and then build the RF probe in the manual in preparation.  As I took the K1 apart again, I was placing the KAT1 back in it's bag (I like to keep the boards and all their parts in the original marked bags when not in the K1 itself), I noticed the jumper that I removed from the KFL1-4 when installing the KAT1 and immediately slumped in my chair.

Sure enough, that was it.  I had removed the KAT1 and moved the RF-DET jumper to K1, but I had not replaced the J2 jumper between pins 2 and 10!  This jumper connects the antenna to the input of the low pass filters on the KFL1-4.  When listening for a signal, it really helps to have some RF from the antenna going in to the receiver!

Once installed, the N-GEN and X2 signals (even the 1uV signal) are loud and clear.  Good thing, too, because I did something wrong with the probe and my DMM is not reading!

Anyway, tomorrow I can thoroughly re-calibrate my K1; both RX and TX.

Thanks for the ideas,

Byron KI6NUL
p.s.  I am using Signal Scope on my iPod touch to monitor the waveforms.  It seems to do a pretty good job.