[Elecraft] K3 not communicating with PC

[David Gilbert]

That would be almost at the bottom of any list of potential problems I 
would suspect.  The only gradual degradation mode I can think of for any 
low power transistor, plastic encapsulated or otherwise, built in the 
last 30 years by any reputable manufacturer occurs when the base-emitter 
junction gets repeatedly and significantly reverse biased.

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?

73, Dave   AB7E


Roger Dallimore wrote:
> I'm going to examine the transistor on the IO board. Apparently the 
> plastic transistors can degrade over time on older K3's and the voltage 
> drops under load to the RS232.  Thanks to K1WHS for this suggestion.
>
>