Shortly before the first portableMotorola DynaTAC "brick" cellular telephone filled the palm of a Wall street yuppie, the original Sharp Sidekick was illuminating the camping trips of working class families. No I'm not having an episode of temporal displacement, or writing an episode of the Twilight Zone. The original Sharp Sidekick was a portable 5" B&W TV, not a cell phone with a slide out screen.

My Grandfather bought a used 1981 vintage Sharp Sidekick model # 3S-62 at a yard sale back in the mid nineties. He gave it to me and it's been sitting on a shelf in a closet for many years. I decided to bring this relic out of hibernation and make it more useful in today's world.

This TV, of course, has an analog tuner and can only be fed an RF signal through the VHF and UHF antenna terminals. This isn't of much use since the transition from analog to digital broadcast in 2009. One way that this TV can be used to watch broadcast, or cable is by installing a 300-to-75 ohm matching transformer, then connect a digital converter or cable box via 75 ohm coaxial cable. Another option is to use an RF modulator to convert composite or S-video signals to RF.

I wanted to have a set of composite (RCA) input jacks built in to the TV for convenience. That's what I set out to do, and with some deduction and a little trial and error I was successful. While I was at it I also upgraded the built in speaker for better sound. Please read on to learn how I did it.

Step 1: Let's Have a Look Under the Hood

It seemed to me that I should be able to find the part of the circuit where the demodulated video signal is fed to the tube driving circuitry. I started by locating the demodulation section, which is housed inside the large metal shielding box. I traced the wire bundles from the horizontal PC board that the demodulator is attached to over to the vertical tube driver board. I determined that a grey three wire shielded cable was the demodulated audio and took note of this for a later step. I guessed that the demodulated video signal feed would be in the larger bundle connected toward the top back edge of the tube driver board.

Wow, thanks for doing this ible, I've been wanting to know how to do this for a while. I have two of them that are waiting for a good purpose. I had four, but one was dead and I choose to harvest it for parts rather than try to fix it, and the other was critically damage while I was turning it into an oscilloscope.
<p>It's satisfying to know that sharing this project, and what I learned while doing it is of value to others.</p>
I have an old Emerson portable color TV / radio. I wanted to use it only to play my NES games but the darn thing does not have a coaxial connection not the yellow red and white connections as well. Is it possible to install them?
<p>Captain Picard, Commander Riker, and Geordi La Forge approve this 'ible.</p>
<p>It would honor me if those chaps took note of my work (especially Chief Engineer La Forge). Just as it does that you did, thanks. </p>
<p>I have an old quasar I want to use this way. Not really confident i won't electrocute myself if i try this. You mentioned using an RF modulator. Can this be used to transmit a signal the TV can receive on its own? there are NO A/V inputs at all. I have searched for transmitters but they are all paired with a reciever that connects by cable to a TV. Do you know where to look for a transmitter that just goes to a channel on the tv tuner itself? The TV is pristine and I really want to put it to use. </p>
<p>Your TV has to have either 300 ohm antenna screw terminals or a 75 ohm coaxial cable jack to connect a signal source. An RF modulator is a wired interface that converts composite signal into RF to be fed into the antenna input on the TV.</p>
just FYI, putting a resistor inline with the speaker isn't really a good fix. the ideal fix would be to properly match the correct inductive load.
<p>If I were working on valuable high quality pro gear, I might be concerned with inductively matching the load. In this case my only concern was that the 8 ohm speaker might draw too much current, and damage the transistors in the amp. The series resistor will ensure that doesn't happen.</p>
<p>Ive got a similar TV that I picked up at a flea market. I'm not savvy enough to prove around high voltages with comfort. Maybe I'll make mine into a lunchbox or something, lol.</p>
<p>I think it's best to steer clear of high voltage if you don't feel comfortable working with or near it. If your gray-scale emanating box is still functional, it seems tragic to tear out it's innards to make room for your hoagie and cheetos. </p>
love it! if I ever come across one I'll be sure to pick it up! probably integrate a nes with it :)
<p>NES + Sidekick = Retro Fun</p>
<p>Nice job! This is so cool!</p>
<p>Thanks for the nice comment! :)</p>

About This Instructable




Bio: Exploring the cosmos one synapse fire and one mouse click at a time.
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