50's Philips Radio Saved From the Grave

After my suitcase boomboxes, I wanted to continue using interesting speaker enclosures. This time I used an enclosure that is actually intended to house speakers and all the additional components. I found a damaged and non-functioning 50's Philips tube radio at an antique shop and immediately liked it. Although it needed some work on the exterior (ripped cloth, corroded metal trimming, damaged wooden frame etc.) I went ahead and bought it. I documented the whole process with the intention of writing an instructable, but unfortunately i lost some pictures. I will still do my best to describe the full building process and I hope you like the end product just as much as I do.

Have fun reading!

Components:

• Speakers - Technics SB CH-404 60w @ 4Ohm
• Radio - 50's Philips tube radio (radio in the picture is not the original but very similar)
• Amplifier - TDA 7492P 2*25w with built-in Bluetooth 4.0 module
• Power supply - Mean Well 24V 6.5A Switching Power Supply (LRS-150-24)

• 12V LED strips and 12v power supply
• Speaker terminal
• 230v socket and 230v switch
• Thin particle board
• Thin oak board
• Dark wood stain
• Aluminum corner pieces
• Speaker and power cables
• MDF board
• Screw terminals
• Electrical tape and heat shrinks
• Velcro tape
• Burlap fabric
• Broadhead screws
• Some nuts and bolts (i used M4 ones)
• PCB spacers
• Plexiglass
• Thermoplastic connectors
• 12v power cable and speaker cable

Tools

• Soldering iron and tin
• Wood glue
• Staple tacker
• Various screwdrivers
• Coping saw
• Sanding paper
• Cable stripper
• Glue gun
• Multi meter

Electrical components

When removing the back plates, the old electronics were visible with at least 20 years of dust on top of them. the lower metal tray was able to slide out as a whole with the glass front attached to it. As I wanted to reuse the glass front, the mechanical switches and the frame, I needed to strip all the electronics off the frame.

Housing

When I bought the radio, the wood casing was in a bad state and the speaker cloth was ripped. Furthermore, the plastic front, the switches and the metal trimming needed a good cleaning. I stripped all components and set them apart to repair them one by one.

(Again, these photo's are not of the original radio, but very similar. I used these photo's to illustrate what it looked like)

Housing and speaker mount

The housing was still very useful but had some drawbacks. There were a lot of holes in the bottom and the speaker mount was made of thin and weak wood with a ripped cloth. These holes were quickly patched with some leftover particle board, but the speaker mount and the speaker cloth was a bit harder.

Eventually I decided to take out the original speaker mount and replace it with the front panel of the Technics speaker cabinet I bought. I had to extend the length a bit and wanted to incorporate the front running light into my new radio. To make all of this secure and airtight i made some mounting brackets and fixed everything to the housing using wood glue and a glue gun. After fixing the inner parts of the housing I started on the outer part. I sanded down the outside and applied 4 layers of dark wood stain to give it the radio it's shiny brown color back.

Front light

The original light was not working anymore so I used a led strip I had laying around and placed it behind the metal light frame. This of course was to bright to resemble the old light. To fix this issue I sanded down two pieces of Plexiglas and glued them on top of each other. By placing this in front of the led strip I was able to create a more diffused light source which would suit this front light better.

Speaker cloth

Since I lost the photos of the building process of the speaker mount but do have the photos of building a speaker cloth frame for the other cabinet speaker, I will illustrate the building process using this example.

1. Cut the cloth to length. Make sure you have more then enough fabric in case you make a mistake or it starts to unravel on the edges.
2. Tack staples to opposing sides on the frame. Make sure to keep the fabric tight. When the first opposing sides are done, you do the second two. Be extra careful on the corners to get the least amount of excess fabric there.
3. To stop the fabric from unraveling and secure it even more, I applied wood glue along the edges.

Since the old back plate was broken and completely filled with holes I recreated a new back plate from particle board. I traced the old plate and cut it out with the coping saw together with the mounting holes of the other components. These components were a 230V socket connected to a 230V switch, and a speaker terminal to connect the other Technics speaker cabinet i had. I hooked everything up to thermoplastic connectors so if i had to remove the back plate from the radio completely, this would be relatively easy by loosening a couple of screws.

Out with the old in with the new!

After stripping the radio from it's electrical components, the only thing I had left was a close to empty metal frame and some mechanical switches. As I felt these switches were really cool to integrate in the use of the radio, I wanted to do something with them.

The lighting

As the backlit lighting and light indicator on the speaker cloth were broken, I wanted to replace them. Luckily I had some warm white (2700k) 12v led strips laying around, as well as a 12v power supply.

Coming back to the still intact mechanical switches. As I was only comfortable with running the relatively low current of the led strips through these switches, I decided to use one of the switches to turn both lights on and off. Using the continuity function of my multimeter I traced down 2 connections which were useful to make this switch work.

Other components

After fixing the lighting i went to work on all the other components. Hooking this up was pretty straightforward. I created a hub where 230v would come in and would be distributed over the 12v and 24v power supplies. The 24v power supply is then connected to the amplifier which would amplify the audio signal and send it to the passive crossover which would distribute the frequency ranges over each speaker.

At this point the radio itself was essentially finished and fully working. Nevertheless there were still some things left to do.

Resonance chamber

As I expected the audio quality of the radio while not having an enclosed space around the speaker was close to terrible. To fix this I made an enclosure out of 10mm MDF board. To ensure the enclosure to be as airtight as possible, I put insulating strips around the edges. This enclosure improved the audio quality significantly.

Stereo speaker

Since the radio consisted of a single 3 way speaker system at the moment and i still had the other speaker laying around, I wanted to combine the two. As the original aesthetic of the cabinet speaker was a bit out of tune with the radio, I thought of a way to make them look alike. To do this, I glued thin oak board to the sides of the cabinet and applied the same dark wood stain as I used on the radio housing. Using the same technique I also made another speaker grill using burlap fabric and an MDF board frame. As the radio also had some metal accents, i thought it would be cool to also incorporate this in the speaker cabinet front. I bought and cut aluminum corners and darkened them a bit with wood stain to give them a weathered metal look.

It's done! I hope you enjoyed this instructable, I surely enjoyed building it.

This build has proven to be very useful and a great conversation piece as well. I use this audio system almost everyday and people are always drawn to it when they first see it. I am also very happy with how it turned out aesthetically, remembering in which state i got it.

I will definitely continue these kind of audio projects which combines vintage items and modern audio components. See you in the next one!