[Elecraft] K3S K-line cabling

[David Aslin G3WGN]

Hi Jack, likewise great to reconnect!
Thanks for your info which together with Don's has helped clarify my thinking (see my reply to Don).
Had a play in CQWW with the 4-el Ultrabeam on a luffed-over trailer tower.  Average antenna height - 10ft.  Worked around the Caribbean and east coast and even managed an ATNO (D68).  Just shows anything radiates! 
Building up now to CQWW CW.  Really miss the NCCC fellowship! Hope to see at least some old friends at Dayton next year.
73, David G3WGN  M6O and still WJ6O


-----Original Message-----
From: Jack Brindle [mailto:jackbrindle at me.com] 
Sent: 27 October 2019 19:07
To: David Aslin G3WGN <david at aslinvc.com>
Cc: elecraft at mailman.qth.net
Subject: Re: [Elecraft] K3S K-line cabling

Hi David! Great to hear form you...

To expand a little on Don’s excellent info, The PC connection for both the KAT500 and KPA500 are mostly used for remote control and firmware update. While you can send data to them from a transceiver (usually Kenwood) to control things, for your situation, that’s not what you want to do.

As Don notes, you want to connect the AUX/IO connectors from the K3 to the KAT500, then from the KAT500 to the KPA500. The big advantage is that frequency and some control information is carried from the K3 to the KAT (using the Auxbus), which it uses to determine antenna and LC selections. The KPA communicates over the Auxbus to the K3 to tell it its status (causing K3 to set power level if that is enabled). This is the only form of serial communications that flows between the three units, and some don’t listen (the KPA) or talk (the KAT). Of course the two units are also watching the K3’s Band lines, which also goes into the selection determination. 

To summarize, the PC connections on the KAT and KPA are really useful for remote control (usually with the KPA and KAT utilities, although some control programs also use them. For what you want, the AUX IO ports need to be connected. 

Lastly, be sure to use a cable with all 15 pins connected straight through. Do NOT use a VGA cable. They play with the signals in those cables, connecting several together, which will mess things up for us.

Hope you are enjoying CQWW this weekend; we miss you in NCCC!

73!
jack, W6FB


> On Oct 27, 2019, at 9:56 AM, Don Wilhelm <donwilh at embarqmail.com> wrote:
> 
> David,
> 
> Download the latest P3 manual and look on page 5.  You will need the CBLP3Y cable.
> 
> The KAT500 and KPA500 use the AUX cables and not the serial data.  The PC connection shown in the KAT500 manual is for connection to the PC for use of the KAT500 Utility and has nothing to do with the normal serial data between the K3 and the P3.
> 
> To get the serial band data to your antenna controller, use a "Y" cable at the PC connector on the P3.
> 
> There are other ways of connecting things as shown on page 6 of the P3 manual, but you will have to connect the PC to the PC connector on the P3 and not use the internal USB to serial adapter included in the KIO3B, but you will still have the USB soundcard that is internal to the K3.
> 
> 73,
> Don W3FPR
> 
> On 10/27/2019 12:08 PM, David Aslin G3WGN wrote:
>> I have upgraded my K3 with the KIO3B interface, so my PC is now connected via the USB port on the radio.
>> My question relates to the cabling for the complete K-line: K3S 
>> KPA500 KAT500 and P3 The cabling diagrams, even in the latest KAT500 manual, show the PC connected via the PC jack on the KAT500.  As noted, my K3 with KIO3B is connected to a PC via the USB port on the radio.  Which connection should I be using?  What difference does it make?
>> I also need to get band data to my Ultrabeam antenna controller (like a Steppir).  Where should I sniff the band data and will a simple Y cable do that?
>> 73, David G3WGN  M6O
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