Reading data sheets for fun and profit

Discussion in 'Homebrew and Kit Projects' started by KL7AJ, Jul 24, 2021.

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  1. KL7AJ

    KL7AJ Ham Member QRZ Page

    I have a vast collection of semi-mystery op-amps and such (sometimes it takes some digging to get info on mil-spec chips, but it's worth the search)

    Anyway....I wonder who else reads data sheets for semiconductors...it can be very revealing, and can suggest totally original applications for the devices. The devil is in the details!
    Eric
     
    N2UHC, WN6U, AB1YW and 2 others like this.
  2. WA9SVD

    WA9SVD Ham Member QRZ Page

    Not just the "data" sheets, but I STILL refer to the National Semiconductor Linear Application Handbooks and Linear Databooks (Ca. 1987-1994.) At least SOME of the devices ('723, LM741, LM301A, etc.) ARE still in wide use, and usable.
     
  3. KL7AJ

    KL7AJ Ham Member QRZ Page

    I remember when the 741 came out, I was a sophomore in high school, and they were about $7.50 a pop (in 1970 dollars). Now they're about 7.5 cents! I always liked the 339 QUAD comparators too....great for making ladder type flash A/D converters. I still have a few dozen of these in their original flavor fresh wrappers.
     
  4. KL7AJ

    KL7AJ Ham Member QRZ Page

    Hey Larry....are the TRW swapmeets still going? (Or whatever TRW shape-shifted into) :)
     
  5. AD5HR

    AD5HR Ham Member QRZ Page

    The NTE semiconductor manual, large as the Sears catalog,was
    at one time a fantastic read for me, (ECL, CMOS and TTL at the time)
    Now it is "sometimes" easier online, but there are a lot of very
    obscure parts out there.
    Also any tube manual I could find.
     
  6. WA9SVD

    WA9SVD Ham Member QRZ Page


    The swapmeets were certainly shut down early last year due to CoViD. I don't know when (or if) they will return; I (sadly) feel the swapmeets won't be brought back until (if or when) LA County and California finally get the virus beaten.

    I was recently looking for LM301A IC's; they are ALL back-ordered everywhere, except for the 10 (or is it 8) pin circular version @ over $10.00 EACH. Thankfully, I started going over my old (and I mean OLD!) stash, and found I had about 8 of the 8 pin DIP IC's already. I really NEED to take inventory of all the IC's and transistors I have stashed away... from about 30 years ago, when I was into homebrew, and DIY stuff. Now, I'm getting back into it again. (Second childhood?:()
     
  7. K7MEM

    K7MEM Ham Member QRZ Page

    I recall, in the past, IC vendors use to come visit the various companies hauling tons of manuals, that they gave away for free. Intel, Motorola, etc.. I still have a complete set of the Motorola Semiconductor manuals among others. Some of the manuals have interesting design descriptions in the appendix. Makes for good reading on the throne.

    I especially like the Motorola RF Devices manual where they describe broad band HF amplifiers. The description included everything you needed to build these amps. The illegal CB amplifier market picked up on this pretty quickly. I have an excellent example sitting on the shelf.
     
  8. K1APJ

    K1APJ Premium Subscriber QRZ Page

    Oh, yes indeed. If possible, I always find the data sheet/application notes for stuff I intend to use. As you point out, almost always the application notes give plans for non-obvious uses of the component. Too, many commercial product designs are perfect copies of designs given in application notes; I had a Fender guitar amp just the other day with a blown power supply, the application note for the control chip explained and detailed the whole thing.

    Now, I wish there was a way to find application notes for "house numbers." I have a certain quantity of IBM components that "escaped" years ago. DB diodes, 151 transistors, etc. Try to find info on those types of parts!
     
  9. WN6U

    WN6U Platinum Subscriber Platinum Subscriber QRZ Page

    At AST Research they brought manuals, samples, and lunch.
     
  10. WA9SVD

    WA9SVD Ham Member QRZ Page

    That's (the illegal CB use) because the Motorola app notes were for circuits that did NOT (in almost all cases) include ANY filtering; THAT was up to the individual user. Of course, why would a "manufacturer" of an already illegal amp care about filtering harmonics, etc. anyway?
    The unit you have "Sitting on your shelf" MAY be usable (legally) on amateur frequencies IF you add proper filtering, either internally or externally. It may also require providing a revised method of bias for the transistors, to be run in linear mode, if it is originally a Class "C" amp.
     

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