Does the SignaLink USB support FSK?
None of our SignaLink products support FSK operation. However, except among a small group of “FSK purists”, this is not an issue because FSK is no longer the preferred method of operating RTTY. FSK used to be preferred because radios we’re not very linear in operation on Transmit, and the only way to access your “good” RTTY filter was with the radio set to the RTTY mode. Today’s modern radios provide excellent AFSK performance in both Transmit and Receive, and most provide complete control over all filtering, so you can still select the “good” RTTY filter while in a digital AFSK mode. AFSK is also preferred over FSK because every other modern digital mode (PSK31, MT63, SSTV, etc.) uses AFSK, and on most radios, switching to FSK would require a completely different cable connection.
