Retro Radio ...

10 February 2017


A Retro Radio for the car ...

While waiting for the next steps regarding the body, I'd like to report a "little" project of last year.

One warning at the start: This makes no sense, it's of the type "why does a dog lick his balls?" ... because he can ...

So what's it about? I wanted a retro radio for my pickup project. Well I could have bought a Becker Mexico Retro or a modern retro radio or an original Becker with an AUX-Input ... no no no, much too easy!

When I was young (!?) I saved up quite some time as a student to be able to afford a Blaupunkt Nashville R24 for my first VW Polo. Autoreverse, Cassette Program Search ... that wasn't too bad for those days! So the thought was in my head to modify such a radio with the following requirements

  • Radio function as it is
  • MP3 Player with a memory card and a random function
  • Up-to-date power supply
  • Cinch-jacks for an external amplifier (internal 2x5W aren't too impressive)

So I got one at Ebay (two more should follow) and started. Done the following:

  • Firstly removed the cassette part
  • Replaced the DIN-Power-Block; rearranged the built-in capacitors and coils as well as the fuse on a separate circuit board
  • Replaced the DIN-Preamp by Cinch-jacks
  • Complete circuit board layouts and wiring diagrams bought on Ebay (a full 4 Euros)
  • With the help of a HW-developer I found the connecting points in the circuit diagram, where the MP3-Player should be connected
  • Changed the front lights to LED (white)
  • MP3-Player (Velleman) bought. Reason: all 7 buttons can be connected externally, SD-Card, small Display (Photo shows already modifications)
Bild in Lightbox öffnen (open image in lightbox). MP3-Player ... already partly modified ...
Bild in Lightbox öffnen (open image in lightbox). All buttons had to be taken apart to modify the cassette buttons to "push" operation ...

The "Need" for a 3D-Printer ...

Next Problem: How to get the MP3-Player in and - especially - mounted? And the Display into the cassette slot? And the SD-card slot into the front?

Solution: Finally found a reason to buy a 3D-Printer and I experimented quite a bit ... and printed a frame for the MP3-Player.

Further Modifications:

  • Connecting plug for the MP3-buttons was on the wrong side: resoldered and bent
  • Rebuilt SD-card slot, i. e. by means of an extended ribbon cable; added a slot into the front cover
  • Disassembled and rebuilt all radio buttons, so that the buttons are working in a tip-function. All buttons insulated on the main circuit board and soldered cables to it. The "Mono-button" now switches between Radio and MP3.
  • Installed micro switches, so that the "fast forward/backwards"-buttons now operate "Track forward/backwards" and the Autoreverse-button works as "Play/Pause"
  • Desoldered the SMD-LED's of the MP3-Player; unfortunately not enough output voltage for normal LED's: installed two Relais, which then switch the 3mm-LED's (with a 470Ohm resistor). So now the green LED is the "Play-LED" and the red LED at the front is the "Random"-LED

The housing and the cassette holder had to be modified significantly. One circuit board I fxyxed up and I finally used the parts of 3 Blaupunkts. Just the best front cover and the best knobs.