On 6/3/17 8:26 PM, Hal Murray wrote:
jim...@earthlink.net said:
I guess the regen receiver must have had some gain at 1 MHz. I found an old
GE datasheet that gives the ft of 0.6 MHz. (and the hfe wasn't bad, 20, at
DC, probably)
But you sure weren't building a 5MHz or 10 MHz oscillator with a 2N107 or a
CK722. Or the 2N170 NPN, which I am surprised to find you can still buy
(and cheaper, in constant dollars, than originally).
Free to good home:
RCA Transistor Manual, SC-10, 1962, $1.50, 300 pages
3/4 of it is Technical Data. Many 1/2 page. Some more than a page.
Lots of germanium. Nothing on the 2N170 or CK722.
GE Transistor Manual, 6th ed, 1962, $2, 440 pages
Nothing resembling a data sheet. There are several tables with parameters.
The Use column for the 2N170 says IF => Intermediate Frequency Amplifier.
the CK722 was a Raytheon part, I believe.
The 2N170 was apparently hot stuff. Slightly before my time (2N404 and
2N1613 were my childhood devices, and amazingly, they're still being
made, although I suspect not on the same fab lines)
Yep, IF, as in 455 kHz (or back then, 455 kc). No FM strip at 10.7 MHz
or TV at 4.5 MHz in 1962.
http://n4trb.com/AmateurRadio/SemiconductorHistory/GE_2N170_NPN_Junction_Transistor.pdf
gives performance *at 455 kHz*.. 24dB gain. People probably thought
they had died and gone to heaven.
There is a chapter on Radio Receiver and Tuner Circuits and another on Basic
Computer Circuits.
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