[Elecraft] KIO2 not working

[W3FPR - Don Wilhelm]

James,

All those voltages look OK to me.  The voltage on pin 11 is dependent on the
state of the signal at pin 6.  If you wish to test it, pull pin 6 to a
negative level (jumper from pin 8 to 6) and you should see pin 11 go to 5
volts - a positive voltage on pin 6 should produce a 0 volt signal on pin
11.  The reason you see zero volts there now is that the chip is
interpreting the floating state of RXD at pin 6 as a positive voltage - all
that is OK because voltages between -3 and +3 volts on the RS-232 signals
are in a region of uncertainty.

Your problem likely lies with an unsoldered connection somewhere or a broken
inductor - check the miniature inductors for continuity.  You had previously
reported 0 volts on pin 2 of the 9 pin connector, but you have -9.85 volts
on pin 5 of U1 - the only series element between those points is an inductor
and it is likely the path is open if the voltages at the two points are
substantially different.

73,
Don W3FPR

> -----Original Message-----

>
> Alright, I followed the steps for "No (-) supply at U1-8" and this is
> what I got:
>
> The oscillator was oscillating at 16.292 mhz
>
> I took the voltage readings of U1.
> Pin 1 = 12.32
> Pin 2 = 0
> Pin 3 = 11.80
> Pin 4 = 0
> Pin 5 = -9.85
> Pin 6 = 0
> Pin 7 = 11.79
> Pin 8 = -9.85
> Pin 9 = 0
> Pin 10 = 0
> Pin 11 = 0 (This is supposed to have 5?)
> Pin 12 = 5.06
> Pin 13 = 4.8
> Pin 14 = 0
> Pin 15 = 4.81
> Pin 16 = 4.81
>
> The serial port is enabled in the menu.
>
>
>
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