Saturday, October 8, 2011

Setting up DVK via USB for TS-590

Digital voice keyer (DVK or DVP, digital voice processor) is a mandatory part of SSB contesting.
TS-590's USB audio I/F eliminates the need for an extra analog audio I/F for digital modes and DVK operation, which is a good news. We will be freed from worries like audio isolation, hum etc. However, setting it up is not so straightforward. Here's how.

  • (Optional) Install the Virtual COM Port Driver if you want to use CAT as well.
  • Hook up TS-590 with a PC using a USB cable. Generic USB audio driver is then automatically installed.
    • Please remember that Kenwood-supplied ARUA-10 (USB Audio Controller) software is NOT required for this operation. It's intended for audio routing within a PC and used for other purposes like remote control.
  • Set Menu 63 Audio input line selection for data communication to USB.
    • This is confusing because Kenwood likes to use the word 'data' for any audio communication through the back ports (USB or ACC2) while you can actually pass anything like voice.
Initially I thought this was enough and I'm ready to go for DVK. PTT can be triggered through CAT. On testing, reception was OK but there was no audio transmission even though PC Audio OUT is correctly set to USB Audio CODEC. Why?

4.2. Setting Transmission Methods for Audio Input to the Rear Terminal  
The [SEND] keys on the PTT of the microphone connected to the TS-590S, and on the TS-590S control panel, are the method for transmitting audio input to the microphone connected to the TS-590S, so even if these operations are implemented, audio entered as audio signals from USB cannot be transmitted.
 It continues (abridged):
To transmit audio input as audio signals from the USB, select one of the following methods.
● Transmitting using the ARCP-590  
● Use the ACC2 Connector’s PKS port to transmit. 
This setting allows you to transmit audio received by the rear terminal by setting the PKS port in the ACC2 Connector on the back of the TS-590S to “Low.” 
● Use the PF key assigned to the DATA SEND function to transmit.
By assigning the PF key to the DATA SEND function, the PF key can be used to transmit audio received by the rear terminal.
Apparently, Kenwood separated Data PTT from Mic PTT for some reason. I don't know why this was done. As a fail-safe method? And what PKS stands for? PacKet Send, perhaps?

Now I'm not going to use ARCP-590 and the PF key thing is impractical, so we have only one option to choose - PKS keying. However, homebrewing a COM-ACC2(PKS) cable (perhaps with an opto-isolator) only for this purpose and hooking it up using a USB-COM converter is not nice. It will spoil the beauty of single USB connection so much.
Postscript: Ian G3NRW has taught me that each of the two methods of PTT (mic and data) mutes the other audio path, thus to avoid mixing up unwanted audio. This now perfectly makes sense to me.
Keying the PKS
I've found two other options to key the PKS without the need for a dedicated ACC2 cable. You need either one not the both.
(1) Use Data VOX.
    • Set Menu 69 VOX operation with data input to ON.
      • This VOX properly triggers PKS, which usual mic VOX won't.
    • Problem with this method is that any PC sound may trigger the VOX and will be transmitted, such as beeps and Windows startup sound.
(2) Assign PKS to DB9 port.
    • This is not in the Menu. By powering on while holding on FM/AM you will momentarily see the message 'PSQ/PKS' in the display. Now PKS is assigned to pin 7 of the DB9 back port which you can trigger using RTS from PC software, much the same way as usual PTT. See TS-590 Instruction Manual for details.
    • With this method unnecessary transmission is less likely but we need a second cable between the PC, which is a little undesirable.
Either way, DON'T trigger the usual (mic) PTT too. It will mute the back port audio (USB/ACC2) even if you use Data VOX or PKS. In most control software, 'PTT via CAT' must be DISABLED.
There is a PC control command that triggers the PKS (data PTT) instead of mic PTT. So if software properly supports this for DVK function, then we can achieve real 'single USB cable DVK'.
Anyway now you are ready to go for DVK. I have tested this with N1MM and TR4W and it worked great!