Why are transistors called "Q"?

From: jpero_at_sympatico.ca <(jpero_at_sympatico.ca)>
Date: Fri Feb 25 20:51:17 2005

John Honniball wrote:

> > "T" was taken (Transformer). That was also a problem when tubes began
> > being used. I think they use X for tubes, don't they?
> >
> > Q" is quality factor, related to gain, but the gain of a transistor is
> > b (beta) isn't it?

To muddy the tea, some makers are starting to use non-standard
location markers:

Philips uses 4 digit numbers, no letters. So you get real tedious
trying to find 1537 location in 1,000 part circuit board in about 15
minutes and no logical area, they're scattered all over. Grrr.

After French took over the RCA, they started putting weird location
marks: It goes like this: LL005 for fly, TL00x for transistor in
horizontal, TV00x for video transistor amps. So on. Totally
confusing because the lettered is even longer than the old system
was and even transformers got the LL also. The ICs didn't get the U
either, I think it is IVxxx, IPxxx etc, also can use other letters as

I miss old system! RCA used to use logical way to locate the parts:
for example:

T,Q, C, etc D are standard component types and is respented as y,
that's easy.

y143xx is horizontal driver circuit area, numbered by xx, sometimes
xxx if the part count is large which is not that case.

y144xx is for actual horizontal circuit.

y141xx is for power supply area (hot side)

So on. That's so sensible.

Again, I wondered about that "Q" too. :-)


Received on Fri Feb 25 2005 - 20:51:17 GMT

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