[Elecraft] Difficulty with K3 Utility RS232 Interface

[Iain MacDonnell - N6ML]

Hi Craig,

This is a guess, but I suspect that your current firmware is too old to
support saving its configuration with the up-to-date K3 Utility - it's
probably trying to use some command that doesn't exist in that firmware,
to read some configuration.

It sounds like your RS232 setup is working fine. If it was me, I'd "bite
the bullet" and go ahead with the firmware update... but you may be less
adventurous ;)

     ~Iain / N6ML



Craig D. Smith wrote:
> I am trying to do a "configuration save" with the latest released K3
> utility.  I'm using a straight-thru 6 foot RS232 connection and get an error
> message saying "K3 Get command failed to return the expected response after
> several attempts".  I posted a help request on the reflector about this a
> week or so ago, and Dick Dievendorff was kind enough to respond with some
> possible ways to remedy the problem.  He suggested that it was possibly a
> bad cable.  I bought a new cable, and it behaves identically.  BTW, both
> cables look fine with a continuity check.  Straight-thru in each of the 9
> pins and the shells.  He also sent me a couple of non-released versions of
> the K3 Utility, thinking that they might help the situation.  Unfortunately,
> they behaved similarly.  So I'm ready to move past the cable and software
> and look at the hardware.
> 
> I've tried the obvious things like reseating the RS232 connectors.  Also, I
> get the same message when running the I/F at each of the 4 speeds.  This
> same RS232 I/F to the K3 works flawlessly with the K3 Utility in terms of
> reading and changing filter parameters and CW memory bank contents.  It also
> works perfectly for rig control/logging with both N3FJP and N1MM contest
> software.  I have had absolutely no problems with noise from the computer or
> with RF in the shack.  The K3 is SN 608, so has over a year under its belt
> with never any other RS232 I/F problem.  I've also used this same I/F
> several months ago to do a configuration save and install new K3 firmware.
> It worked just fine then.  
> 
> The present situation is that I'm running version 2.02 firmware and would
> very much like to update it to version 3.11 so that I can have access to
> some of the latest features.  But I'm hesitant to try a firmware install if
> the RS232 I/F is "flakey".  The last thing I want is to have the K3 totally
> inoperable due to a botched attempt at a firmware upgrade.
> 
> I saw that there was a mod in the modification list that removes the 100 uH
> inductor from the RS232 return line.  Thought this was worth a try, so
> jumpered out the inductor.  Unfortunately no change in the situation.  While
> I had the RS232, ACC I/O board out of the K3, I checked to see if there was
> anything else obvious there.  Nothing definitive, but a couple of things to
> note:
> 
> The RS232 Application note states that "Do not use the metal shell of the
> RS232 or ACC connectors for chassis ground.  They are normally isolated from
> the chassis."  On my board, the RS232 connector shell is isolated and the
> ACC connector shell is tied to frame ground.  Is this normal?  What is the
> reason for wanting the shells isolated?  Can this contribute to the problem
> I'm having?
> 
> There is a deviance between the latest K3 schematic and my RS232 hardware.
> On both the RXD out and TXD in lines, my hardware has a 220 ohm resistor in
> series with the inductors.  No resistors are shown in the schematic.  Please
> clarify.
> 
> Unfortunately, I have no other computer here with RS232, so can't try
> changing computers.  
> 
> What should I try next ?????
> 
> I'm copying the reflector in case anyone else would like to offer
> suggestions.
> 
> 
>  Thanks and 73
>                       .... Craig AC0DS
> 
> 
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html