Not very many T0264 even today.
But yes On Semi seems to still be making the larger packages.
T0264 package listed as MJL
MJL3281AG
MJL1302AG
30 MHz fT 200 Watt
MJL4281AG
MJL4302AG
35MHz fT 230 Watt
Been curious to try out NTE M200 packages
NTE 92
NTE 93
But yes On Semi seems to still be making the larger packages.
T0264 package listed as MJL
MJL3281AG
MJL1302AG
30 MHz fT 200 Watt
MJL4281AG
MJL4302AG
35MHz fT 230 Watt
Been curious to try out NTE M200 packages
NTE 92
NTE 93
Do you know the typical junction to case and case to heatsink thermal resistances for these MT-200's?
Best regards!
Best regards!
0.625 C/W, same as any other plastic case 200 W device.
NTE buys them from wherever they can. Since they can’t get them from Sanken anymore, they are forced to use the same potentially disreputable clones/fakes that the rest of us are.
On Semi seems to be the last hold out for the TO-264. I think even Toshiba wants to get rid of it. On might even phase it out eventually. They are taking their time entirely phasing out the metal can, though, so there is hope.
NTE buys them from wherever they can. Since they can’t get them from Sanken anymore, they are forced to use the same potentially disreputable clones/fakes that the rest of us are.
On Semi seems to be the last hold out for the TO-264. I think even Toshiba wants to get rid of it. On might even phase it out eventually. They are taking their time entirely phasing out the metal can, though, so there is hope.
This was a very useful thread. Can you confirm what transistors you used, and how you mounted them?
Well for the Yamaha I used MJL1302/3281 and I just drilled and tapped new M3 holes into thr heatsink.
I have another thread here somewhere when I did the same to a Kyrocera A-910. Due to the way the originals were mounted to the heatsink the general consensus was that the smaller NJW1302/3281 were a better fit. I also drilled and tapped for those as well, but doing it over again I think using the original holes and a small bar to clamp the outputs would have been better.
Here are some pics from all that
That amp runs pretty warm, but has been going strong for several months now. Sounds as great as it always has too.
Next time I’m going to try some other devices, like the NJW21193/21194 since I have a few dozen of them, as well as the 2SA1943/2SC5200. I’m certain any of them would work in this situation depending on the exact devices you’re replacing.
I’d say that if you have the room that the TO264 is the safer choice, though in two instances where I used the smaller TO3-P there hasn’t been an issue at all, so maybe they’re fine.
Dan
