MAPUCHE 2600 - Portable Wobbulator
by Dan Chelger
1 Viewfinder Sony DXF-501CE (included in broadcast cameras like DXC-537, DXC-D30, etc.)
1 Cube CCTV camera with CCD Sony Super HAD II 1/3” sensor and 16mm fixed iris lens
3 Function generator kits based on XR2206 IC
3 60w Class D Mono Amplifier modules based on TPA3118 IC
2 DC-DC 12v Voltage Regulator modules based on LM2596 (1 for camera and viewfinder, the other for the three function generators)
1 24v 10a PSU 1 Atari 2600 (we gonna use the case and the 4 main switches) 6 10k Resistor
3 1k Resistor
3 4.7k Resistor
3 100k Resistor
1 or 2 Header 20 pins female (total used = 19 pins) for the Patch Bay
1 or 2 Header 6 pins male (total used = 6 pins) for the Patch Bay
1 Experimental generic PCB 10cm x 5cm for the Patch Bay
6 50k Linear Pots (you can also use the ones on the XR2206 kit)
3 100k Linear Pots (you can also use the ones on the XR2206 kit)
3 2 position, 2 poles, 4 contacts Slider Switch (use for frequency change on the frequency generators)
1 2 position, 1 pole, 2 contacts Slider Switch (viewfinder on/off)
200gr or less enameled copper wire 0.30mm (H and V deflection coils)
100gr or less enameled copper wire 0.40mm (S deflection coil)
VERTICAL: 2 30/40mm diameter coils, 260 turns aprox each, 0.30mm coil diameter, connected in parallel. 8 ohms each, 4 ohms total when connected in parallel.
HORIZONTAL: 2 30/40mm diameter coils, 260 turns aprox each, 0.30mm coil diameter, connected in parallel. 8 ohms each, 4 ohms total when connected in parallel.
CIRCULAR: 1 40/40mm diameter coils, 260 turns aprox each, 0.40mm coil diameter. 4 ohms total induction.
How to calculate coil turns? http://production-solution.com/coil-calculator.htm
TIPS & WARNINGS - READ CAREFULLY BEFORE BUILDING:
- Square generator outputs are not amplitude regulated by original design. Amp pot is useless on it. Square power output is higher that SIN/TRI output so it’s recommended to use SQUARE out just for AM purposes. Using that output connected directly to amplifiers can lead to dangerous coil overheating.
- Function generator amplitude pot legs are inverted by original design. They must be inverted.
- Voltage regulators can be uncalibrated. Use trimmer pot included to calibrate prior tu use.
- Viewfinder Horizontal deflection come originally inverted. This can be fixed by taking out H deflection connector on viewfinder board, inverting RED and BROWN cables and connecting again.
- Always discharge TV tubes prior to work with them. Leaving it charged can lead to risk of electric shock and also death if the shock goes thru your heart.
- Viewfinder boards have BRIGHTNESS and CONTRAST controls. Those are really important for image calibration. They must remain exposed so they can be used live when needed.
- Constantly test voltage amplifier outputs when building and testing. Also test coil temperature. At 15v they start to heat. At 18v the became really hot. At 24v they melt plastic and can start fire, representing a real danger.
- Coil turn quantity can vary. Build each coil and test it by rubbing coil ends with sandpaper and connecting those poles to a multimeter so you can measure 4 or 8 ohms needed. There can’t be cuts inside coil, nor exposed sections (without enamel).
- Parallel H and V coils connection and positioning on the viewfinder must be by respecting current flow. Current “input” must aim to the same side and be connected together. Same with coil/current “output”. Coils have always two connections, each one is physically oposite to the other. So as an example, both connections that aim to the right must be connected together, and when installing, you must respect that. Do not turn the entire coil so those connections ends one aiming to the right and the other to the left because you’ll be generating two opposite magnetic fields. The idea is to have two identical magnetic...Read more »