[Elecraft] K3 not communicating with PC

[Lyle Johnson]

> What specifically were the details of the supposed issue with older 
> K3's?  Does the RS-232 line in the K3 reverse bias the emitter junction 
> (exceed BVebo) of that transistor?

No.

The KIO3 uses a twin-tee oscillator to generate to required negative 
voltage.  This is to eliminate the typical charge pump as a source of 
receiver noise.  About a year ago we changed the transistor used in this 
oscillator to a higher-gain device because a small number of KIO3 
modules had marginal negative voltage.

There is no degradation with time that I am aware of.

73,

Lyle KK7P (guilty of designing the KIO3 module)