[Elecraft] KRC2 silkscreen gotcha

[Gordon LaPoint]

I have two KRC2's, one uses the aux-bus line with a K3 and the other 
uses the RS232 with a Kenwood TS590sg. The only problems I have had are 
all self induced with programing errors!
They both work flawlessly and have for years, one drives a WX0b Six Pak, 
the other drives a MFJ RCS-20Lx switch.
Gordon - N1MGO

On 11/19/2020 16:26 PM, Paul Fletcher via Elecraft wrote:
> Hi Paul,
>
> I’ve not used it with a radio yet, this was to communicate with a PC to configure the KRC2 (though the same issue would apply to anything using RS232). The KRC2 wasn’t responding at all hence the start of fault finding and the findings I posted. As soon as the resistors were corrected everything worked as it should without issue.
>
> Hope this helps.
>
> 73 Paul M1PAF
>
>> On 19 Nov 2020, at 20:52, Paul GACEK via Elecraft <elecraft at mailman.qth.net> 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 <wes_n7ws at triconet.org <mailto:wes_n7ws at triconet.org>> 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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