Retrofitting a 1960s Sony Clock/Transistor Radio [Part 1]

I have a problem with not being able to be satisfied with a project that should be considered completed. I think this is the case for most everything I create. I’m always thinking about how I can improve the project, or if there is a part of it that I was happy with at the time, but now I think is sloppy. The problem with this is that if I know there is something I can improve and I end up not enacting those changes, then I am unsatisfied with the end-result of the project. I’m going to go ahead and call this the Perpetual Project Predicament.

I have been working on and of with this project for almost seven months now. There was even a point where I thought I was finished and put it aside… two times even. I love this clock radio’s design so much that I feel I need to do it justice, since when I got it from Value Village, it was in working order.

How the clock radio was found on a shelf in Value Village

Plugged it in at home and I was honestly a tad surprised that everything was working as expected. The coating showed signs of wear and tear, as did the plastic faceplate, which had abrasions around every knob and dial from years of volume and channel adjustment.

Showcasing the clock’s wear. Surprisingly decent, considering this thing is like 56 years old!
Not the best picture, but you can see the damage to the wood around the face plate.

The clock had a neon bulb wired directly to the mains with two resistors. It was quite faded, so this was my first idea for the retrofit: Replacing the neon bulb with some LEDs. However, this was not the first thing I did. What I decided to do first was replace all of the electrolytic capacitors in case any of the decades old electrolytic fluid dried up.

The original amplifier, before any modification.

Here we see the radio’s original amplifier. The two green cables to the right are from the transformer – positive and negative 6 volts AC. The intertwined black and yellow wires are the audio out, attached to the speaker. There are three wires attached to the top of the board, all relating to volume and tone.

The long blue wire is simply a jumper from one side of the board to the other. You don’t see that kind of stuff anymore and that’s a reason why I found these boards to be so fascinating. The PCB and it’s traces, all look very human-made. Notice the speaker’s rating; 0.8 watts is pretty tiny!

Not until much later do I realize a critical mistake that I made during this project with relation to that clue on the speaker. That small grey capacitor is one of the first to be replaced on this board. I don’t seem to have any pictures of that process though.

Here I am in the process of figuring out how to convert the radio’s audio source from the actual radio tuner bit (the board with the white square) to a simple phone jack (3.5mm, the type used on headphones). Both boards pictured relate to the capturing and processing of radio frequencies and were not needed.

First test run to make sure I didn’t break anything.

Once I traced where the audio source led to, I was able to discard a few components and hook up a 3.5mm phone jack to the volume potentiometer ( the one attached to the braided white, blue and green wires). Connected the transformer to the mains AC cables along with the cables for the clock module, pictured on the right.

Plugged it in, played some music from my phone and everything worked as expected!

Nekkid!

Decided to take a break from the electronics-side and refinish the clock’s enclosure. Not pictured are the other times I thought I had sanded to the substrate, only to realize that I was incorrect.

Hand-sanding can be a massive pain. The only tool I used here was my trusty Dremel to get into some of the harder to reach areas

Starting to look good

It was only at this point, after the fourth coat of stain was dry, did I notice the sanding mistake I made near the top left edge. I sanded against the grain here, and didn’t notice until it was too late. It does kind of bug me, but it’s not normally that noticeable.

Other than that mistake, I think it’s starting to look really good! I’m definitely partial to the darker wood stains. I used an old shaving lather brush to paint it. I think that’s the reason for the amount of stain spattered all over. Probably should have done this on a larger piece of cardboard or a trash bag.

Oh jesus

What is this monstrosity? Yeah, it’s pretty bad. I was just trying figure out the placement for everything inside the case. This is also where I introduced a Raspberry Pi to the mix. Had the idea of being able to switch the audio source from 3.5mm phone jack, to the audio output of the RPi (running Plex Media Server).

I de-soldered any unnecessary or large components from the RPi, then set about figuring out a way to re-attach the Pi’s USB ports in a way that would work in the case. This did not happen to be the way (no shit). That big black cable with two usb ports at the end is meant to attach to a motherboard USB 3.0 header.

Zip-tied to the power transformer on the right is a 5v USB power supply. It has a micro USB cable for powering the Raspberry Pi, and added mains cables for tying into the system’s other cables.

The speaker is another addition. I had a hell of a time finding a speaker that would fit inside of the metal tray, which is surprising since I have a large surplus of them. The one I chose here is 8ohms (same as original speaker), but is rated for 4w instead of the original 0.8w.

Also visible are all of the new capacitors that I replaced on the amplifier board. Fun fact: that large, brown 100v 1000uF cap is from a salvaged Macbook charging brick.

It fits!

I managed to come up with a good way to mount the Raspberry Pi. Those bits of plywood in the back are attached to two bent pieces of metal (which originally held the radio’s graphite rod), which are attached to a bit of board, which have motherboard standoff screws attached, which the RPi is screwed into. Later I do away with the two bits of wood and use only nuts and bolts.

I still have not come to the conclusion that the USB breakout that I made is not going to work.

Ghetto prototype

There was an empty horizontal slot that the radio’s tuner display once occupied, so I decided to prototype a VU meter to fill that void.

Here’s a demo of the prototype VU meter. The audio source in use here is the amplifier board from the radio.

Gotta rep the Cold World Hustlers (Straight Doin’ It)

Hope you’ve enjoyed part one of this project. I’m thinking there will be at least another three in the immediate future.

Come back next time where I will make fun of every mistake that I made and die a little bit inside. Yay!

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