[Elecraft] KIO2 KIO2/100 Not working

[Don Wilhelm]

David,

Check the simple things first.  Do you have PORT turned on in the 
secondary menu?  Do you have sidetone on that K2?  If not, then that is 
the problem.
OK, you don't see a direct relationship between sidetone and computer 
communication!  It all involves the use of U6 pin 25.  It originally was 
the sidetone source, but later U6 pin 25 was changed to TXD.  If your 
sidetone source is set to U6 pin 25, the microprocessor cannot 
communicate with the computer.
The current firmware allows the user to switch the sidetone source 
between U6 pin 25 and U8 pin 4.  Enter the menu for ST L, hold EDIT to 
'edit the parameter', then tap DISPLAY until you hear sidetone.

Note that there are only 2 signal lines involved in the computer 
communication - TXD, RXD, plus signal ground.  The level conversion from 
TTL levels to RS-232 levels is the only function of the MAX1406 chip in 
the KIO2 and the KPA100 - if you have computer communication problems, 
these are the only lines to concentrate on and check.  The levels at the 
pins of the AUX connector will vary depending on conditions at the 
input, so stating any voltage at the connector pins could be in error at 
any given time.

Don't forget that the computer may also be at fault - check with another 
computer, and check the cable to the computer for breaks in the signal 
lines.

73,
Don W3FPR

David N. wrote:
> Hello All 
> My K2 K2/100 stopped working with the computer I tried just with The K2/100 and just the KI02 and still nothing. I cannot get the oscillator at 16.289 +/- 10 khz I believe the problem lies in the K2 itself I checked for bad solder joint on the Aux plug  on the control board that connects the KI02 from eith the KPA100 or the KIO2. still no luck Can anyone tell me what the voltage is on the AUX line? I do not have a scope to troubleshoot with I only have a volt meter.
> Thanks 
> David KR4OW
>   
>