[Elecraft] K3: Added protection for RS-232 port

[Don Wilhelm]

Pete,

I am not certain why you believe the K3 RS-232 port to be "fragile".  I 
have not seen a large number of failures identified on this reflector.
There have been quite a number of users who have had problems with USB 
to RS-232 adapters, but that is not a failure of the K3 RS-232 port.

Can you give me some examples of RS-232 port failures on the K3?

73,
Don W3FPR

Pete Smith wrote:
> I've been thinking about how one might go about adding some protection 
> for the apparently fragile (and expensive) RS-232 port on the K3.  It 
> might be possible, if the components were small enough, to add them on 
> the KIO3 I/O daughterboard, or perhaps on a little external board 
> mounted at the port.
>
> But the question is, what components?  I have seen small gas tube units, 
> but suspect that by the time the potential reaches 90 volts or so and 
> the tube flashes over, the RS-232 transceiver is probably toast anyway.  
> Would it be feasible to use fast diodes to shunt the data lines to 
> ground at .7 volts or so, or would that introduce other problems (stray 
> capacitance, etc.)?  Anything else that might make sense?
>
>