If only using a computer you do not need a TU.  There are many sound card programs for rtty. MMTTY is a very food free one.  There are other programs that decode rtty and other digital  modes.  You do need an audio interface that is just a simple circuit to isolate the computer and radio. It can be the same kind that is used for PSK31 and FT8.  You can even just put the microphone of the computer next to the radio  to receive rtty and other digital modes.  You could do the reverse to transmit but not advised as any other sound in the room would get transmitted and not be legal except maybe an FM or AM signal in the VHF bands.

If a mechanical teletype machine you will need a TU (modulator/demodulator) from the radio. 

Ralph ku4pt

From: [email protected] [mailto:[email protected]] On Behalf Of Windows XD
Sent: Sunday, July 30, 2023 6:20 PM
To: [email protected]
Subject: [GreenKeys] Terminal Unit Reccomendation

I've just learned that I will need a TU to transmit over HAM radio as well as connect to my computer and use it as a keyboard/printer/ITTY, what would be a good unit to get?