I used my TS50 with an original RigBlaster Interface for many years.
One thing you will note is that the TS50 doesn't have any ALC indication, which you
would normally rely upon when adjusting TX audio for Digi-modes. PSK31 in particular
is picky about the audio levels.
The trick to survive without the ALC indication is to follow what I call the 50:50:50 rule.
1) Set the power output on the TS50 to M which is 50 watts (ie 50% of maximum power). You need to do this as PSK31 is essentially 100% duty cycle on TX. (Be nice to
your PA transistors!)
2) Adjust the soundcard TX level slider so that it is not more than half way (ideally it should be a bit less to give you some room for adjustment). Most computer
soundcards produce very poor output if overdriven. This is the source of most IMD.
3) Adjust the TX audio level on your interface box (there should be an adjustment) so that that rig is showing 50% of the power that you have selected (i.e about 25W) on peaks in tune mode in PSK31. You should now be able to make minor adjustments with the software slider without
overdriving anything.
So 50% of total power (50w), software TX slider level at no more than 50% and adjust interface so that peak output in PSK31 Tune mode does't exceed 25W (ie 50% of the selected 50W).
If you follow these simple "rules" you should get good IMD reports on PSK31 and you should
have plenty of power to make lot of QSOs.
Michael VE3WMB
P.S. I now use a SignalLink USB (which I really like) with a couple of different rigs (the TS-50
has been relegated to backup rig status). What like about the SignalLink USB is that it is in itself a decent external USB soundcard, but it is also very convenient to have access to TX and RX audio controls on the front of the box without have to fiddle with slider controls in software.
I see a couple of hams online are using the Signalink USB with the old (but very good) Kenwood TS-50.
I wonder if anyone here has direct experience of this or other interfaces with this old time rig? I look at the manuals, listen to the moans about wrong diagrams, the cables that do or don't come with the unit, and quickly give up trying to figure out what might actually be a simple PSK31 solution (if such a thing exists!) I'm rather amazed at the contacts made already with manual keying of the mic, but it's a bit tricky typing and keying at the same time, hence the need for an interface!
Any help, advice or experience greatly appreciated (don't tell me I can build one - I'm about as useful as a 'p' in pneumonia with electronics; I just like communicating!)
Thanks,
J.