Well, if that is what he is asking, I can only respond by saying you should be using current manufacture from licensed distributors.
Thanks, I don't use those brands, so I am at a loss when it comes to judging them. It sounds like you are saying that the Mospec devices would be the best bet if you had to go that route.
-Chris
Thanks, I don't use those brands, so I am at a loss when it comes to judging them. It sounds like you are saying that the Mospec devices would be the best bet if you had to go that route.
-Chris
Problem is you can’t get everything from suppliers such as Mospec, Central, or Solid State. They offer a lot of generics, but no dice on Japanese types. If you need something specialized like a MT200 LAPT you really *are* SOL unless you need a couple of the mismatched types still in stock at Profusion or Digikey. Good luck getting a complementary pair. TO-3 ring emitters? Heaven help you if that’s what you absolutely *need*. Go get your DeLorean now and make sure you have enough plutonium.
Most of the time for new DIY projects and the majority of repair work you can just one of the 15 or so complementary pairs you can still get in current production and don’t even have to resort to second sources. Not always possible commercially, and exact matches may not always be found for repairs. Retrofitting case types or extra parallel pairs may be required. Such may be a kluge, but it may be that or no amp at all. I guess it’s six of one half dozen of the other if you need something generic TO-3 you *can* get from a second source supplier. Whether to use it, or stick in an ON Semi MJ15024 and be done with it. You can make a case for either.
Most of the time for new DIY projects and the majority of repair work you can just one of the 15 or so complementary pairs you can still get in current production and don’t even have to resort to second sources. Not always possible commercially, and exact matches may not always be found for repairs. Retrofitting case types or extra parallel pairs may be required. Such may be a kluge, but it may be that or no amp at all. I guess it’s six of one half dozen of the other if you need something generic TO-3 you *can* get from a second source supplier. Whether to use it, or stick in an ON Semi MJ15024 and be done with it. You can make a case for either.
Those do not appear to be real - sorry. Yes, you can see the sanding marks on top,and the bottom finish is completely wrong, as are the lead insulators.
The question now becomes, are they reasonably fakes or not? Can you measure the capacitance E-B and C-B? Compare to measurements earlier in the thread. Or, you can pop the top off one to see what it really is.
-Chris
The question now becomes, are they reasonably fakes or not? Can you measure the capacitance E-B and C-B? Compare to measurements earlier in the thread. Or, you can pop the top off one to see what it really is.
-Chris
Base-emitter capacitance will be at least 4500 pF with these types. Any “real” transistor, even a 2N3055 will be hard for you to pop the top off of. If it comes off easy it’s no good. Even if the die were ok, there could be contamination issues which could cause early failure. That’s why they put on the white goop, but it’s only partially effective. The visible ring from the bottom is a giveaway that the seal is probably not done properly. Some manufacturers parts DO look like that from the bottom, but ON (and older Motorola) never did. Even then, the tops would not just pop off with a pair of pliers.
The only real ones labeled “MEXICO” instead of “MEX” are some early Motorola ones - with the domed top hats from the late 1980’s. I wonder why you don’t see any of those being passed off as fakes. I do buy old vintage Motorola types when I can find them cheap. But never gotten burned by an older style package - so far they’ve all turned out to be real. Mostly the aluminum ones before they started using an origin code. And of course I always test purchase first. I have seen some spec fall outs in a batch (low Hfe, leaky, etc) but look just like the good ones inside.
The only real ones labeled “MEXICO” instead of “MEX” are some early Motorola ones - with the domed top hats from the late 1980’s. I wonder why you don’t see any of those being passed off as fakes. I do buy old vintage Motorola types when I can find them cheap. But never gotten burned by an older style package - so far they’ve all turned out to be real. Mostly the aluminum ones before they started using an origin code. And of course I always test purchase first. I have seen some spec fall outs in a batch (low Hfe, leaky, etc) but look just like the good ones inside.
Hi.I have measured my Original MJ15004 and it is 11,85grammes and this fake looking MJ15003 measures 11,8grammes with my precision weight scaler.
And i have DER EE DE5000 LCR meter.Can i measure with this?At which frequency?Thanks
These are 100% authentic transistors .
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Not a transistor but a voltage regulator. On many transistors I know at what I have to look at but at this one I'm not sure. I've got this one in a regular kit but when I examined it closer I got some doubts if it's genuine or not.
I've made a few pictures of it but it is hard to see on them what makes me suspicious,
the surface looks not flat but seems to have waves on it. It feels flat though. To show it more clearly, I've edited the last picture. I know, maybe I'm just paranoid right now but I'd like to be sure because a replacement from china would take too long for my project (preamp) if I had to order possibly damaged parts on the preamp.
I've made a few pictures of it but it is hard to see on them what makes me suspicious,
the surface looks not flat but seems to have waves on it. It feels flat though. To show it more clearly, I've edited the last picture. I know, maybe I'm just paranoid right now but I'd like to be sure because a replacement from china would take too long for my project (preamp) if I had to order possibly damaged parts on the preamp.
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