Well I have a negative voltage on U2 pin8 but it is 3 volts higher than
the manual. Probably not an issue
Rich
On 11/19/2020 16:58 PM, Paul Fletcher wrote:
The circuit diagram and the parts placement in the manual are correct.
On mine it was the silkscreen for R12 and R13 that was reversed. Let
Jack do some digging as it’s possible (from his comments) that this
doesn’t affect all boards. Mine only arrived a few days ago. The easy
way to check if there is an issue is to check there is the correct
negative voltage on pin 8 of U2. Mine was almost 0V before swapping
the resistors.
On 19 Nov 2020, at 21:41, Rich <[email protected]
<mailto:[email protected]>> wrote:
Thanks for the info. Could you post the correct value of R12 and R13?
Mine was back at Elecraft way back. I want to make sure it is
already not corrected
Based on your info R12 should be 47ohm, correct?
Thanks
Rich
On 11/19/2020 15:52 PM, Paul GACEK via Elecraft wrote:
Hi Paul
Thanks for the heads up.
I had some communication issues with my KRC2 in that it worked like
a champ with my K2 but not so with my KX3.
I’m going to crack open my krc2 shortly and see what values I have
in those two resistor locations.
What radio where you using with the KRC2?
Paul
W6PNG/M0SNA
www.nomadic.blog <http://www.nomadic.blog>
On Nov 19, 2020, at 12:47 PM, Wes <[email protected]> wrote:
Thanks. I've owned one of these for years and as I recall, it's
always been a problem so it's been resigned to the junk box.
Maybe I can resurrect it to make it useful for something.
Wes N7WS
On 11/19/2020 12:58 PM, Paul Fletcher via Elecraft wrote:
FAO anyone who's had issues getting the serial comms working on a
KRC2:
R12 and R13 are transposed on the silkscreen on the PCB. I fell
foul of this
when I recently built my KRC2 and it wouldn't communicate. After
quick probe
around it was evident there was no negative voltage to the RS232
driver, U2.
A little further probing revealed no 12V present at R13 but there
was at
R12. It was then I realised the component layout in the manual is
different
to that marked on the PCB. A quick swap of resistors and
everything works as
it should.
I've re-read the errata and the manual and there is no reference
to this
issue. Apologies if it's been flagged up on here already but I
couldn't find
anyone pointing this out though there do seem to be a few people
with serial
comms issues with the KRC2.
Hopefully this is of assistance to someone.
73 Paul M1PAF
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