I just acquired an IC-706mkll (new to me) and have lots to learn. It does have the cw filter installed. Since I really do not do alot of cw work was wondering if it will be useful. Am wanting to get into digital modes in near future. So would it be best to keep it or swap out for the ssb one?
Which one? IIRC, there were two possible options. I have the 500 hz one and wish I had the 350 hz unit. Because my hearing (decoding) of the code needs all the help it can get.
The 706 is a decent CW machine, better with one of the filters. 500 Hz will probably be OK for you, but 350 would be better for contesting or DX hunting. For digital modes, the standard SSB width should do fine - the digital modes have their own software filters. I don't remember if you can turn the AGC off on 706, but if you can, that will help with the digital modes. The only concern about the digi modes is heat. I would hold the power down to 20-25 watts or even less. To do that, turn the RF OUT all the way up, and adjust the audio drive to the transmitter from the computer.
For digi modes like the popular FT8, the rig has to be in "SSB" mode. I don't think the IC-706 family allows selecting the narrow CW filter while the rig's switched to SSB. Maybe it does, I don't remember and it's been years since I used one. In any case, you don't need to "swap out" the narrow CW filter for an SSB filter, as the Icom came with a good SSB filter to begin with! If you find yourself never using CW, you might consider removing that filter and simply selling it. Might bring $100 or so assuming it works fine; I don't think Icom sells these anymore, and only see SSB filters for the IC-706 on the INRAD website, so maybe they don't sell the narrow CW filter for that rig anymore, either.
For digital modes like FT8 and PSK31, you'll be in upper sideband (lower sideband for AFSK RTTY) and you'll want the widest filter you have--at least 3Khz.
On RTTY with that radio both the 500Hz and 350Hz filters would be fine. There are few comments about that radio and RTTY at https://www.aa5au.com/rtty/rtty-radios/
