I Just found some GDR-Amp

I got myself a little treat (10 Kg of scrap electronics) and inside I found, among other great stuff, a GDR board that was made by RFT. It seems to be some kind of stereo amp or Tone control circuitry because of its symmetric nature.

We have a 2761 Dual opamp and 4 E X3 C36 (?) transistors at work alongside 4 Styroflex(polystyrene) (you gotta love em) caps.

I asked around in my favorite forum where some old-timers hang out and that were in electronics back in the day, when there was the GDR. I’m hoping to find out some more soon and get this thing going!

AE EP#27 Gameboy Crystal Hack

robot797 asked me to play around with the clocks of gaming consoles and I liked that idea. So I think fiddeling with an N64 in that way could work but I settled with a classic Nintendo Gameboy. Turns out, that ye olde Z80 doesn’t mind the dodgy clock at all.All I needed was a rotary switch and some quartzes (2, 3.3, 4,19(original) MHz).

AE EP#26 The Ultimate Breadboard

While I was working on my Oscilloscope project I discovered, that breadboards are only semi-useful for Bigger things. Everything seems not to add to your project but to just pile up on it. After you added some probes and things that need a bus you will sit on a fragile, unforgiving crapstack, that just waits for you to stick a jumper-wire in the wrong hole. So I decided to make myself some room on the board and push connectors, displays and meters away from the center. Just take a look what came out:
Breadboard in a pic

check out the vid to get a walkthrough

So here is a little list what it includes:

* 2 max 232 Level converters
* An arduino NG
* 3 BNC connectors
* 8 banana Plugs
* A 50 V voltmeter
* Tiny tiny breadboard for displays and button stuff
* 4×7-segment display with driving transistors
* Datavision DV-20208 HD44780 compatible LC-display
* 2x lm3914 bar-graph displays with jumper selectable voltage range
* Avr-Net-IO for some Ethernet
* A -10V -5V GND +5V +10V earth 0V 35V Power supply
* and of course a humongous breadboarding area

This is of course just a source of ideas so if you make one of your own please let me know and if you don’t publish yourself, I’d be delighted to show off pictures of yours here!

Some words on construction:
The base is made from a piece of structured plastic (45 x 30 cm) on top of that are some pieces of wood with some plastic veneer that form the body. This makes up the wedge form in the back. On top once again I used some sign plastic covered with red spraypaint, why red? because its shiny 🙂
Ground and Earth are normally separated and can be connected on demand.

List of inspiration and components




http://www.oppermann-electronic.de/html/sortimente.html the Voltmeter was in this pack: Einbau-Meßgeräte-Sortiment 10 verschiedene, Volt- und Ampermeter und Hz-Messer

Here is a little zipfile containing the PSU-design and the VU-meter: PSU_LM3914

PS.: the space above the tiny breadboard is reserved for some raspberry-pi…