Kazizilkree I used my time as a student as an example because it happened to be where I first saw an HC device. Balanced mixers had advantage. You moved further into the hobby and learned where you could substitute parts, you came to know the familiar solid state devices so you knew that diode was germanium and needed germanium, but that small signal bipolar transistor in an audio darasheet could be just about any small signal transistor, so long as it was NPN, and even then a PNP could often work as long as you made adjustments. Datasheet pdf. Equivalent They wanted to use what they had, or what they could scrounge.
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Monos Another example would be lm But there do appear to be some parts that I would try to sub for the in an old receiver design: Datasbeet is exactly what I suspected. In general, they still keep the same functionality and numbering-scheme. And connectors seem to be not a focus of theirs in the way semiconductors are. Datwsheet I specify a transistor with a low price and an equivalent substitute I can be sure that my employer will be able to buy that part well datashret the future.
I repaired a big brand audio Amp late last year. Which exactly are the parts that have superseded the 74HC? As a mixer with LO input: This is probably leftover from my war years: Get a 1N82 if you wanted better frequency response, thy were found in UHF tv tuners. In some cases, part numbers become descriptors rather than absolutes. Because radios are now becoming all microprocessor and nothing else, does that mean that someone should stop designing mixers using transistors?
Not all markets are like this. The other camp wanted cheap. I think TI has it right and they recognized where they needed to be with things. BF, unless my memory fails me. The most expensive single chip I use today is the AD Not perfect, but acceptable for a lot of uses. Those people probably bought the kit if it was available.
The second gate also made it easy to control the gain when used as an RF amplifier. And people wonder why I hoard old analogue TV tuners. Others would use the same device, because someone had chosen it. Pocket money single board computers with real power and easy interfacing.
I use a as a mixer as it happens, and in my application you start to hear the performance tail off somewhere above 10MHz with the HC part. Now all gone, the average cellphone today has no useful parts. In the early sixties, the JFET came along, those were seen as less prone to overload. You are commenting using your WordPress. The big retailers still have catalogs. They contained significant excerpts from semiconductor data sheets, and we read their wealth of information from cover to cover.
So blindly switching from HC to AC is a bit dangerous. Circabipolar transistors also had improved noise figure. Germanium point-contact diodes, for example. Extremely useful and they are dirt-cheap. Datasheet pdf. Equivalent As far as I know, those boards are still being built the same way today.
Higher performance mixers like a diode double balanced mixer would likely require way more components as well as an extra RF amp stage and a diplexer. We knew by heart what each device was capable of, and we eagerly devoured each new tidbit of information as it arrived. What the full-blown rant in the previous paragraphs has been building up to is this: They needed to know what was going on in the circuit, and the general specs of the semiconductors.
Notify me of new posts via email. There is of course also a slightly macabre alternative scenario. Related Posts
40673 DATASHEET PDF
Maubei If HC does your job then of course, use it. Other things came long. There were always two camps. But searching for cow brings up an equally useless mosfe Of course, if you know of a good candidate for replacing theplease share the details. My EE course tried to teach me to be an EE academic more than mosvet did a professional engineer.
40673 MOSFET. Datasheet pdf. Equivalent