[Elecraft] K3/KPA500 question

[Bob Wilson, N6TV]

On Tue, Apr 27, 2021 at 8:34 PM Andy Durbin <a.durbin at msn.com> wrote:

> "It's not clear why this feature of the KPA500 is a "PITA," since the
> majority of users want the rig and the amp. to always be locked to the same
> band.  "
>
> And that is exactly why the band buttons are a PITA - If pressed they
> would ensure that my KPA500 is NOT on the same band as my transmitter.
>

Well, a few milliseconds after you transmit, the KPA500's frequency counter
will automatically switch the KPA500 back to the right band.


> if I want to select bands, I would do it with the TS-590 band buttons
> which each provide a 3 deep frequency/mode stack.
> I don't need any help.  I have effectively defeated the KPA500 band
> buttons but I only added that code after I realized the risk they presented.
>

OK, but for others who may be curious, the KPA500 can automatically track
the band of TS-590S with no computer and no custom code required.  Just a
connect a straight serial cable from the KPA500 *XCVR (RS232)* jack to the
TS-590S *COM* port, and set the KPA500 MENU as follows:

RADIO to SERIAL
RS232X to the baud rate of the TS-590S COM port
SER POLL ON if the TS-590S is the only device connected to the TS-590S COM
PORT
-or-
SER POLL OFF if some other device like an RS232 band decoder is polling the
radio on the TS-590S COM port, in which case both KPA500 and the device can
be connected in parallel to the TS-590S COM port via an RS-232 Y-Cable or
S-BOX.  SER POLL OFF uses a relay to open the TXD pin of the KPA500 RS232
connector, so the usual problems caused by connecting two RS232 devices in
parallel are no problem.


Now the KPA500 will automatically track the band of the TS-590S, as will
an RS232 band decoder or similar.

73,
Bob, N6TV
https://bit.ly/S-BOX