just wanted to introduce you to my latest project ... I worked on it for the last 4 months.
One warning at the start: This project 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)
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)
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 ... here some samples:
- 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
So and finally it was finished ... here the bottom:
here you can see the micro-switches:
And put together:
Connectors at the back:
and the final result:
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. Now a duration and rattle test ... then my special-Retro-Radio is done!
Hats off to all who read up to here