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I'm currently trying to make a simple 3 channels RF remote control circuit but without any ICs or micro-controller. I'm Googling but it seems to not populate (useful results). Does anyone have ideas?

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  • \$\begingroup\$ Do transistors count as ICs? \$\endgroup\$
    – The Photon
    Dec 14, 2012 at 17:22
  • \$\begingroup\$ The line for when you count certain components as ICs is a bit hazy. Not including such seems like an exercise in futility, It can be done reasonably with just OP-amps, but are they ICs? \$\endgroup\$
    – Kortuk
    Dec 14, 2012 at 17:23
  • \$\begingroup\$ What sort of information do you want to transmit on the three channels? \$\endgroup\$
    – Dave Tweed
    Dec 14, 2012 at 17:24
  • \$\begingroup\$ @ThePhoton: No, ICs I mean the thing like blackbox :D, I want to build an curruit from R, L, C, Trans, Wire, and any things we can easy make ourself \$\endgroup\$ Dec 14, 2012 at 17:28
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    \$\begingroup\$ @BìnhNguyên Not related to your question but on how to use this site: Always wait for at least 24 hours or a number of answers before accepting one. You will not be encouraging people to give more answers (some new answers may be better). As a guide, try to settle out first all pending inquiries in the comments before accepting an answer. \$\endgroup\$
    – shimofuri
    Dec 14, 2012 at 18:10

2 Answers 2

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Here's a couple of transmitter circuits from this page and a few receivers. To be historically accurate, the receiver would drive a relay with three tuned reeds to activate three channels, according to the frequencies modulating the transmitter...

Enjoy!

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    \$\begingroup\$ +1 You gave the OP a perfectly valid answer given the rather laughable design constraints, and he accepted the answer! This probably says more about human nature than electrical engineering, but it is still worth the +1. \$\endgroup\$
    – user3624
    Dec 14, 2012 at 18:48
  • \$\begingroup\$ To be honest I was hoping someone would chip in with slightly newer references! (@Binh : feel free to un-accept the answer!) Though as it happens, it's not so silly an idea; triode valve circuits adapt quite well to JFets (and tetrode to JFET cascodes), and these have a quite amazing simplicity about them. (though transmitters nowadays really OUGHT to be crystal controlled...) Replacing the tuned reeds with opamp-based bandpass filters might be quite a reasonable concession to modernity... \$\endgroup\$
    – user16324
    Dec 14, 2012 at 20:19
  • \$\begingroup\$ @BrianDrummond: Thanks, but if possible, you can edit your answer :D Again: Sorry for my bad english :-( \$\endgroup\$ Dec 15, 2012 at 14:55
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An author named Paul Newell wrote a couple of books both called Theory and Practise of Model Radio Control, the first edition described building a four or five channel AM 27MHz proportional RC set, no ICs all transistor, they used to allow 100kHz adjacent channels with that spec. He rewrote it to describe another set with more channels, FM (FSK), narrower (maybe 10kHz offset?) channel spacing, that version used ICs from memory. The first book dates to the early '70s, the later maybe early '80s.

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