Introduction: Old Radio Restoration
After my previous Instructable got so many positive reviews, I've decided to share another project with you. This time it's the restoration of this vintage radio that I found in an attic. So without too much talking, let's get into it!
Quick disclaimer though: This radio is using old electron tube technology, so if you attempt a restoration like this, make sure you have the knowledge required to tinker with high voltage.
Step 1: Some Info...
This a "Radio Popular" S561A, also known as "Armonia". It was made in Romania in 1954 and has 4 bands: broadcast, long wave and two short waves, also features a phonograph input and two EQ presets.
Considering its age and the conditions it's been stored in, I didn't want to plug it in, not even for a quick test. The old dried-out and leaky capacitors would have shorted everything out, reducing the chance of an easy repair. Not saying that it was easy to fix, but still. Could've been worse. First I wanted to see whether it's worth restoring or not. If the electronics are shot than there's no point fixing the cabinet and creating the false impression of a working radio.
Step 2: First, the Electronics
If you've seen some restoration video of an old radio or an amp, then you might know that all capacitors need replacing. This is no different situation. All the paper-oil and electrolytic caps had to be replaced, excluding the wax and ceramic caps in the tuning circuit. Also worth mentioning the amazing design of the band switch: the fine-tuning capacitors and inductors are on a rotating circuit board with contacts on the other side and wipers on the chassis. By pulling on the tuning knob and turning it, you engage a gear witch then turns the band switch circuit board into the next position. Pushing in the knob turns the main tuning cap.
First i cleaned the chassis and all other parts of what seemed to be oily sawdust, and started working on the electronics. After the recapping was done, the radio turned on just fine and managed to pick up a few stations, but I did some small adjustments to the tuning circuit and the EQ to make it sound better. It needed a new output tube because the old one was way over its lifetime. The indicator bulbs were also changed with new ones and some of the wires needed replacing too. Due to their age the plastic insulation cracked or stiffened up and were about to make contact with the chassis. I took apart the volume pot, cleaned it and re-lubricated the tracks and wiped all the sockets and switch contacts. I also added a fuse and a holder for extra safety and a 150nF capacitor parallel to the power transformer to reduce popping and cracking sounds in the moment of shutdown. With all this done, I moved on to work on the cabinet.
Step 3: The Cabinet
This one had a rough life. I have no way to confirm it, but it seems like something caught fire on top. The varnish was chipping off all over the wooden cabinet and it had white paint marks all over the back. It's made of laminated sheets of some sort of wood and a part of the top layer was cracked and missing on the front left side. I thought about just leaving the cabinet the way it is but then I decided to give it a go. Now... I'm not an expert in woodworking, as you can see on the pictures, so don't blame me too much because of how it turned out :) .I removed all the original paint using 80 grit sandpaper and an electric blade tool thing (not sure what it's called). It was an exhausting and time consuming event, but after a few afternoons it was complete and ready for painting. Before painting though, I went over all surfaces with a fine sandpaper and applied a bit of machine oil on it to make the wood look darker. I let it absorb the oil for a few days and then applied the first layer of lacquer. In total I applied 4 layers of the varnish to achieve the color I wanted and finished off with a semi-glossy clear coat.
The speaker cover cloth was not too dirty so I left it as is. I was afraid to wash it because it was glued to a wooden frame and I didn't want to damage it. After all the paint was dry I assembled the radio and the project was complete.
Step 4: Finished.
Oh. And not to forget the badge.
All in all it was a long project but it was definitely worth it. The radio has amazingly good reception, it can pick up stations from all over the world without an attached antenna. The sound quality is what you'd expect from a radio of this age. The paper speaker is not the best quality one, but to keep it original I left it in. Even with this, the sound is warm, with enough bass and treble, and a bit eager mid-range, but pleasant to listen to. And of course it looks great. It earned a place in my collection.