In th old days alot o shops used them. I avoided it because I could usuall get te OEM for less. The 123 and 159 for exa,ple were just 2N3904 and 6. I used to joke that you pay more for the bag than the part.
Actually NTE was not first. Their "line" was the same as ECG which was Sylv ania, ECG stood for Electronics Components Group while NTE stood for Nu Ton e Electronics. Another cheap brand using the same cross reference was ERS, and those were not even as good as the others.
And none of them ever made a part. They simply remarked them, and sometimes didn't even do that. The SK line sold by RCA was actually better quality, and of course RCA mad/makes some semiconductors. I imagine they have access to better ones and can control the quality better. They used a totally dif ferent set of numbers though.
In my work, I got to the point where I didn't even bother with part numbers . the application told me what was needed, and for those who say that ain't kosher, I remind you that most shops used ECGs or NTEs which was much wors e.
My system was better. For example 2SC1887 replaces 2SC1885 for most line oi utput in RCA NTSC sets of certain years. They are identical except the 1887 is a bit beefier. So I can buy 20 of those and get the discount instead of buying ten 1885s and ten 1887s. Upgrading a line output transistor in the US has been perfectly kosher since about 1976 when it became illegal for th e safety of the set to depend on the failure of a seiconductor device. Befo re then they counted on the transistor failing to keep the HV should certai n faults occur which would ake it rise to undesirable levels.
Same with the 2SC1881 replacing the 1879, they are slightly different than the 1885/7, but the same as each other. And then in audio there were the po pular pairs to blow the 2SC3280 and 2SA1301. Well of course I gave them 2SC
3281 and 2SA1302.
Certain transistors are critical though, bias transistors in amps I like to stick with the original if at all possible, in fact oin most audio when it comes to the audio chain itself. When it comes to voltage regulators, rela y drivers etc., it really doesn't matter. But for transistors that actually amplify audio or video, you want the specs really close. That means lookin g at the spec sheet.
I bought the books in the old days, not I just get them online. I have very little problems finding most replacement parts for old stuff. Alot of peop le like me started doing the same thing and that pretty much marginalized t hese replacement lines. And now, lately I needed an FM IC for a Technics re ceiver and has no choice but to use an NTE, and the thing didn't work right .
No choice at all. I have stayed away from those thing if possible for at le ast twenty years.