I have owned several TS-440SAT's over the years, and have found them to be very rugged. Reliability was a problem over time with dry joints and shorts caused when sealant adsorbed moisture giving rise to instability. It is, without doubt, very poorly filtered against RF pickup, and must always be connected to a very good earth system. That on its own is not enough, as internal filtering and decoupling are required throughout the rig. The necessary mods are easily found on the internet and are an absolutely required step in transforming this rig into great performer, a labor of love for sure!
The TS-440 Yahoo Group contains a wealth of information and experienced assistance, membership is strongly recommended. I use my 440 mostly for digimodes, the cooling fan mod is mandatory here. My current 440 is fully loaded with Kenwood 1.8KHZ SSB and 270Hz CW filters, my Timewave 599zx provides additional SSB filtering and doubles as an excellent modem for PSK31 and RTTY, and my Datong FL3 multimode filter works well on phone, the manual and auto notch way better than the built in notch filter, even when modified. The Datong itself needs the cutoff frequencies lowered by modification to improve the performance, easily done. The use of Inrad filters will deliver superior selectivity performance over standard Kenwood filters and are recommended. The built in antenna matching unit works well, within tolerance, for band edge matching, but the factory components need replacing with more rugged equivalents to avoid common failures. The SGC QMS-37 mobile auto matching unit works extremely well with a variety of antennas, when properly grounded, giving complete and reliable all band coverage at 100w SSB. The RX audio is not helped by the cheap internal speaker, a good quality replacement or external SGC digital filtered speaker for mobile use works very well. TX audio has brought many complimentary remarks, especially when the better quality Murata filter was fitted. The built in excuse for a speech processor leaves a lot to be desired, here the Datong RF speech clipper works very well for DX as does the latest TenTec offering. The AOR digital voice unit takes TRX audio to another level when communicating with similar equipment, the shape of rigs to come!
So, now that the handfuls of ripped out hair have grown back and my 440 works to my satisfaction, I would recommend this tough little rig to anyone.
Got this one for $50.
It had the all dots in the display issue.
I spend 15 hrs cleaning the VCO, replaced a varicap. And resoldered 20 + cold solderjoints + 150 suspects. These where on all the boards.
It now works to original specs, I'm stoked.
Nothing wrong with this machine.