In fact, for any non-trivial transistor or op-amp circuit you Google for, most of the designs you get are incredibly dated. And now, AI answers are reinforcing the same biases, so I guess we're gonna be stuck here for a long while.
In that way an LLM could make electronics design a lot better and not based on historical accidents as it can do a lot of testing and characterization that few people would do today.
I'm excited to set up my electronics workbench with a bus pirate and my cheap scope to do a little bit of reverse engineering.
A current amplifier is a current amplifier, there's not a lot of complexity until you start worrying about stuff like base capacitance and whatnot.
So, sure, "at the right time" is correct, but really any good/cheap/available BJT that arrived at that time would have won.
[1] Op-amps are even more generically jellybean-like.
I ended up with the exact same ultimate performance and a higher cost and supply chain risk.
I don't laugh at 741s anymore. (At least, not until I've looked at the rest of the schematic.)
The European part numbers provided much more information than the American part numbers.
JEDEC 2Nxxxx just told you that this is some kind of transistor or thyristor, instead of being a diode like 1Nxxxx.
BC told you that this is a silicon small-power audio-frequency transistor.
There were separate codes for other materials and for many other kinds of transistors, diodes and thyristors (for example AD = germanium high-power audio-frequency transistor, BF/BL = Si low/high-power RF transistors, BS/BU = Si low/high-power switching transistors, BR/BT = Si low/high-power thyristors, BA/BY = Si low/high-power rectifiers, BB = Si varicaps, and many others).
Motorola and some other US companies, like Texas Instruments and Fairchild, entered the transistor market very early, when they defined types like 2N2222, which became industry standards.
However, because these devices were defined early, they had rather poor characteristics. When European companies like Philips, Siemens, Thomson, SGS-ATES entered the market later, they defined transistors and other devices with improved characteristics.
Because of this, in Europe the devices with European part numbers, like BC337, were generally preferred, because they provided better analog performance, e.g. lower noise and higher bandwidth.
However nowadays this has become mostly irrelevant, because a legacy transistor vendor makes only a small number of different kinds of transistors, distinguished mainly by die size, because bigger sizes are needed to handle bigger currents. Then the transistors are packaged and marked with any of the legacy part numbers, depending on what part number the customer orders.
So while old transistors may have quite different characteristics depending on the part name, many modern transistors behave the same, regardless how they are marked.
BC breaks down as a silicon device, with no heater voltage, and a "triode".
If it was germanium, it would be AC <something>.
So BC548 is a silicon "triode", AC128 is a germanium "triode", and PC97 is a triode with a 300mA-rated heater (P is series connected with other valves, 300mA) in a B7G base (the 9).
"BF" might be an RF transistor although "F" was really used to mean a pentode in valves.
And those dual NPNs used in expo converters in synths might be accurately enough labeled as BCC548, similar to the ubiquitous ECC83 dual triode.
You also see this with diodes, were AA119 is a germanium small-signal diode, and BY127 is a silicon high(-ish) power rectifier diode, for example.
Oooh that's what it means!
But yes the European code makes (a bit) more sense
Though I never used a BS/BU code, only BD and the TIP series which might be a proprietary code
(and I think you had it up to 546 with an ever higher voltage)
$60 per transistor?? The military is getting ripped off by its suppliers.
Even the DigiKey price is nuts, you can get functionally identical transistors from China for less than a penny each.
You shouldn't have to think very hard about why the military does not want to buy parts from China.
The problem with Chinese semiconductors isn't performance or meeting specs, at least not these days. It's counterfeits, life expectancy of the source companies, and the obvious risk of basing your supply chain on a foreign political actor that can leverage this dependency against you.
This is why quadcopter drones, built using uncertified consumer parts, are cheaper than the missiles to shoot them down.
Sure, they can't buy it from China, but China and its allies can. This is a problem for the US.
https://www.digikey.com/en/products/detail/shenzhen-slkormic...
When they are not, that is when the design engineer earns their pay.
So there are TONS of pin-compatible-ish parts from different manufacturers that have related specs with a ton of variation.
https://www.digikey.com/en/products/detail/diotec-semiconduc...
