Retrobörse in Vienna 2012

Luckily I had some time last Saturday to visit the Retrobörse Wien 2012. A bunch of vintage enthusiasts and traders gathered at the Freihaus (part of TU-Wien) to chat and trade old computer games, computers and consoles. I really had to restrict myself not to buy some good condition N64 – but what would I do with it? I haven’t got no TV 😀 Entry money was 3 € which I think was okay, many people (like me) were just lurking and the cleaning lady has to be paid too.

Nevertheless I got some fine Pictures, down below some more on a really cool project aiming to get Atari into the 21st century:

My friend Markus playing some good old frogger on a system I didn’t even knew existed: the TI-99:

The one I saw in close-up. If you want to know more visit their austrian user group at

This is one classic mad in my very own country by the “Post” that held a monopoly on postal services in Austria up until the early 2000nds. Sorry folks, I didn’t catch your name. get more info on the Mupid here and here.

Atari 800 XL goodness…

.. in all its glory plus some peripherals.

And now some Atari/cpu/fpga awesomeness:

This board is here to combine vintage goodness with a modern operating system and speed (~246 MHz atm). Doesn’t sound too much eh? Well these Atari’s have been stuck @ ~5 to 40 for almost 2 decades. Still there are enthusiasts out there and I had a lengthy talk with the two guys at the stand. One of them started his own button manufacturing – all designed with native Atari software check out his ebay shop.

The Firebee has some really nice hardware on it like a cyclone III fpga and some nice freescle processor. Visit their site here (WARNING, ONLY CLICK IF YOU HAVE ONE EVENING FREE ;D). It will bring out /all/ important pins – from scsi to the old buses, to interface your 1983 Casio Keyboard or the trusty synth. Remember Homers face, when he saw that super-sweet jelly venus?……

Luxury Junk

I just couldn’t resist bidding on some ebay deal where a guy sold his cellar of HIFI-electronics.
There was /much/ more than shown here. This are the parts, I probably gonna use in some way.

JVC GR-SX9 Video Camera

Some very old (1991) Camcorder, I gotta look into connecting it do the pc to finally get some descent webcam input.

AIWA AD1250 Stereo Cassette Deck

This is some very solid case, it will probably house a synth or a mixer in the future.

Blaupunkt 60W 3 Ohm Car Speakers

Just that, they’ll go into a boom-box.

Premier CB 2000 Citizen Broadcast Radio

This one is interesting because i want to get a ham license in the near future. It does not work atm but I’m on it. the amp on top is known as a “Brenner” (afterburner) or “Oma” (grandmother) here in austria. using such an HF-amp with CB is strictly forbidden. (4W only, 12W with SSB)

Hornyphon 6391 Stereo Amplifier, front face

Hornyphon 6391 Stereo Amplifier, inside

Yeah this one needs some serious cleaning and testing but it could very well become a good mate in the future.

AE EP#31 Zombiecalypse TV Station

Yeah this means we will have some more TV, when the undead arise!
This is a super simple setup – with only one flaw: under most jurisdictions it is illegal 🙁
But if we replace the Antenna with a wire and a 10 to 100 Megaohm resistor we are all good to go!

So come on Zombies and give me a chance as a program director 😀

The RF-mixer can be found here

The block diagram:

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#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 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…

AE EP#22 Electron Tubes Basics & Example Amplifier Project

In this video I quickly cover the electron tubes basics and show a little tube amp project, that uses the 1T4 (DF91). The 1T4 is a low voltage tube that can be operated from 45 (it actually works with 12V too) up to 90 VDC and a heater with only 1,5 V. It is also very cheap and can be as NOS for about 0,5 to 1€.

To make more bang I just put two tubes in parallel. In my configuration the whole set-up makes about 150 mW of sound power.

Find the circuit I followed at: (german)

AE EP#21 Minerva Minola 3 Teardown

This is just a short teardown of the classic austria-made Minerva Minola 3 radio from 1967/8.

Here the promised pics:

Full front view of the Minola 3 in all its glory.


The two Varicaps:
Up: the gear to the varicap on the pcb.
Below: LW and MW system.


External speaker connector on the left, back in the middle the impedance transformer for the speaker and on the right mains transformer with fuse holder.


Front-panel switches and pcb from below.


The main board mounted on the chassis with tubes. The paper in the middle acts as a diffusor for the front panels back-light.


I’ll post an update if I ever get the schematic to fix the Volume pot.
Find out more at:
More about Minerva at:
Nice holidays to you all!