[Elecraft] KPA500 not responding to K3

[Ben Collins-Sussman]

Folks, the K3 has two serial ports:  a standard RS232 for talking to a
computer, and an 'ACC' port for talking to the amp.  Same situation with
the KPA500:  an RS232, and an AUX port.

On both devices, the speed of the RS232 port is changeable.  But those
ports aren't being used at all!  The ACC on the radio is connecting to the
AUX on the amp.  And those are not configurable ports.

Just upgraded the KAT500 from firmware 1.41 to the latest 1.67, as
recommended by W0MU.  Saw the "optimize for kpa500" button and did the
deed.  (All it seemed to do was automatically put 1500 in the max-watts
box.)   Regardless, it didn't seem to fix anything.  Still no communication
at all between radio and amp, with tuner as the middleman.

I'll try N6ML's test next, which is a great idea -- just connect the K3
directly to the amp, leaving the tuner out...



On Fri, May 2, 2014 at 12:03 AM, W0MU Mike Fatchett <w0mu at w0mu.com> wrote:

>  I just got a KAT500 a couple of weeks ago and was talking with Eric.
> The Beta's which might have been released to live by now had many changes
> that would make the the three device all get along much better.
>
> I am pretty sure you need to set the baud rate on the KPA500 and the K3 to
> the same rate.  Ie 38400.
>
> You will need to get the usb-serial cable to do the updates.
>
> The KAT 500 acts as a type of Y or WYE for the 15 pin cable.
>
> You should have got a the pc interface cable with the KAT500.
> Download the current utility and then download version 1.67
>
> Under configuration you should see a big button that says Optimize for
> KPA-500.
>
> Push it!
>
> I was told to put 1500  in the maximum watts box.
>
> save it and see what happens.
>
> The KPA 500 should switch to the right band on rf.  It is strange that it
> will not amplify.
>
>
>  On 5/1/2014 10:43 PM, Ben Collins-Sussman wrote:
>
>  On Thu, May 1, 2014 at 11:32 PM, W0MU Mike Fatchett <w0mu at w0mu.com>wrote:
>
>> Go download the latest beta versions of the firmware and the associated
>> utility programs.
>>
>
>  The K3 is new and has the latest official 4.38 firmware.  The KPA500 is
> about a year old and running firmware 1.23.
> I don't have a usb-serial cable yet, though I can grab one tomorrow at the
> store;  is there a specific bug fixed in some beta firmware release?
>
>
>>
>> Have you set the baud rate in the K3 to that of the amp?
>>
>
>  I see nothing in either manual about the K3 or amp having configurable
> baud rates to communicate with each other.  Do you have details?
>
>
>>
>> When the amp is moved from standby to Operate you should see a message in
>> the K3 that says KPA500.
>>
>
>  I see nothing at all.  This is a 3rd example, I suppose, of the total
> lack of communication between K3 and KPA500.
> Again, keep in mind that the K3 isn't *directly* connected to the KPA500.
>  They're actually both connected to the KAT500 tuner, as the diagrams
> specify.
>
>
>
>>
>> I would check the firmware.  I know there is a special button you push on
>> the KAT500 that optimizes operation with the KPA500.
>>
>
>  I see nothing about this in the KAT500 manual, but will look again.
> The connection between tuner and amp has always worked; I haven't touched
> that special DB15 cable at all.  However, perhaps the new DB15 cable that
> arrived with the K3 is physically defective?  I'm digging for hypotheses.
>  :-)
>
>
>