"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...
Didn't you mention once that the way it was designed, back then, was on a regular PCB using discrete transistors, resistors, etc. that were built using the same process the final IC would be using?
I guess that some parasitic inductance and capacitance couldn't have been that big of a deal, eh?
I faked my first analog IC projects because the analog chips were too expensive.
You could take a uL914 dual logic gate and make a long tailed pair diffamp out of them. As in the IC67 metal locator.
Even earlier, I took a MECL gate and used it as a linear amp.
Prior to switcap being released, companies would breadboard switched capacitor filters. Even after switcap was released, I recall one modem project I was working on where the entire chip was breadboarded. In this particular design, the DSP and uP were off the shelf items, so we only designed an analog front end.
Needless to say, we scaled up all the capacitors. I don't even recall the ratio, but probably a factor of 100.
Actually the MC1530 pre-dates "kit parts". I think I bread-boarded with 2N2222's.
But the design is all mathematically balanced... see my website for the analysis.
Not for such a design.
...Jim Thompson
And there's a MECL diff-pair I made a harmonic mixer out of, and wrote a paper about.
...Jim Thompson
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