[Elecraft] "K3 VFO A not responding" message

[Paul M Dunphy]

On 11/27/2012 12:09 AM, RLVZ at aol.com wrote:
> Hi Guys,
>   
> I've been a happy K3 owner for aprx. 3 years.  Regardless  which CPU I use,
> I've always had an occassional problem receiving the error  message "VFO A
> not responding".  When this happens  while "running" during a contest it
> presents a serious problem as the  computer and radio lock up for aprx. 30
> seconds.
>   
> During this 3 year span, I've operated with a dozen  different Windows XP
> and Windows 7 computers, always using N1MM Logging  Software.  I've operated
> from several different QTH's and have the  same problem.  I always connect
> via a Serial Port  regardless of which CPU I use and have not tried a USB  to
> Serial Adapter.  During the past few months, this problem has  really
> increased, such as: during last weekends CQWW  Test, I got the dreaded "VFO A not
> responding" message and computer lock-up  at least once every hour.  By the
> way, I do not have a 2nd  receiver in the K3 so I cannot say if I'd have
> the same problem with VFO  B.
>   
> I'd be grateful for ideas on how to eliminate the "VFO A not  responding"
> problem.
>   
> Thanks & 73,
>   
> Dick- K9OM
>

     Just a guess, and a poor one because you have used multiple 
computers, but what about RFI?  Try reducing the baud rate down one 
interval and/or putting a RF choke on the serial cable.  It's not likely 
that, but I can't think of anything else and it sure sounds like a 
communications problem.  Are you driving an amp?

73, Paul VE1DX