[TenTec] Remote tuning knob/encoder for Omni 6

[Barry N1EU]

Can anybody provide little info on the following:

1. How was the 301R remote tuning knob connected to the Omni 6?  I believe
it connects to unused pins on the DB25 serial port connector, but was a "Y"
cable used or did the 301R connect between the computer and Omni 6?

2. Reportedly the 302R remote encoder can be connected to the Omni 6.  Can
anybody provide connection info?

3. What page/section of the Omni 6 manual shows the DB25 connector?

Thanks & 73,
Barry N1EU