You can also find the TS570D and TS570S on the used market. The 
difference is that the S has 6 meters, while the D stops at 10 meters.

Like the TS480, you will need to have a CW filter installed in a 570 if 
you use it for CW. This is because without the filter, the AGC will 
respond to a signal that is outside the audio passband in the CW 
position, and will drive you absolutely nuts without the filter.

I have owned a TS570S since 1997, and bought a second one a year later. 
I still have both of them.

Speech chips and filters for the 570 are pretty easy to find, although 
the used filters are almost as expensive as new ones.


There are no extra filter options for the TS590, they are all included, 
and are fully adjustable from the front panel.

Be careful about a used TS440. While they are good, they have some PLL 
and display problems that surface as they age. There are a few places 
that will still re-build the PLL circuits when they become troublesome, 
but the Avvid website says the parts to fix the display are no longer 
available.

Of course, if you are totally blind, the display won't be an issue, but 
when either of the PLL circuits begin acting up, the TS440 is useless 
until it is repaired.

-- 
Mike Duke, K5XU