[k1] The puzzle of my new K1...

[John H Farmer]

Hello Group,

I'm pleased to announce that K1 #2822 is born - after a long gestation.

I had couple of hitches along the way, which I thought might be interesting
to report:

I got as far as the end of RF board Part 1 in the build and came to page 36
of the manual where I power up for the first time.  Powered up, but the LED
test and start up routine failed and the rig "hung" with the yellow ATTN LED
glowing and the LCD blank, no relay clicking heard.  To cut a long story
short, a bit of sniffing around showed there was no voltage on the 6A line
due to an open RFC6 on the bottom of the RF board.  This was removed.  The
leads were intact, it was just open circuit when I put the ohmmeter across
it.  I replaced it and the 6A line voltages were then correct.  Problem was,
the rig still wouldn't start.  Same symptom with no LED test on power up:
just the single yellow ATTN LED and a blank LCD.    Occasionally, if I very
rapidly cycled the power on and off, the initialisation routine would
progress, the LED test would complete normally and the rig would come alive.
But only until the next power down.  Then I was back to a dead rig.  And
this trick only worked sometimes.  So I sent off an email to Elecraft.

Gary, at Elecraft support, was great and has the patience of a saint.  With
his help, I discovered that the 6r/aux line voltage was low,  consistently
sitting at 288mV, measured at Pin 8 on the MCU. There was continuity along
the 6r/aux line onto the RF board, through the connector,  and no shorts to
ground.  Gary's theory was that there was a problem with the MCU.  He
shipped out a replacement and I installed it, but the problem wasn't fixed.
Big disappointment.  Plugged the new MCU in, powered up, but same low 6r/aux
line voltage.  I went over that front panel at least 10 times, rechecked
every part, re-flowed every accessible solder joint.  (Fortunately, MCU Pin
1 and Pin 8 are all accessible).  No obvious problems there, but no working
rig either.

So, in frustration, I went on and completed the rest of the RF board.  I
just installed the parts, thinking I'd reached the end of my know how and
would need to send the K1 off to Elecraft.  I got to the end of the RF board
build, powered up and guess what - it started up normally.  I couldn't
believe it, because I'd done nothing at all to the FP board during the build
of the RF board.  Now the 6r/aux line voltages were all normal:  5.94V at
the MCU.  All perfect.  

The calibration and alignment procedures were a breeze. I put in the KAT1
and adjusted that.  It all works perfectly.  And what a great little rig it
is.  Probably the most sensitive CW rig I've had, fun to use and it looks so
cute sitting here on my desk.

So that's my story.  It puzzles me still what all this was about.  I'm
hoping the problem has gone for good.  Time will tell...

73 and thanks for listening,

John
VK7JB


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