ARPEN GERADOR DE BARRAS TV – This is a Brazilian branded Monochrome TV Bar Generator. It was given to me by a good friend of mine, and my mentor, since I lived on Presidente Prudente. It was green colored when I got it but I did a black colored electrostatic painting on it. It worked nice since the first day. It was made around 50's.
All-tube design, the ARPEN can generate only Monochrome Bars. It has provision for 5 channels, and has no VSB filters, on the RF output. This means that a signal transmitted on Channel 4 can disturb the sound and image on Channel 3. I adjusted the RF output for channels 2, 3, 6, 7 and for 45.75 IF. You must wait for 2 or 3 minutes to the horizontal sweep stabilize. After that the operation is very smooth.
I like this generator because I can insert its signal direct on the CRT cathode, without worrying about damage it. It has a large 0.47µF/600V capacitor on the video output to block all DC. It has provision to negative going or positive going video, so you can use in any kind of CRT TV. Obviously its signal is very far from the correct sync pedestal, back porch, and the other parameters RS-170A required for appropriate NTSC-M or PAL-M (Brazilian TV system) operation, but for some repair jobs or just to disturb your neighbor's TV, it is perfect. I had installed a Balun on the RF output and a potentiometer to control the output level, but the shielding of the unit is not good and the signal "escapes" to the outside. By using an external attenuator, this effect is minimized.
AC Inlet: 120V 50~60Hz
4:3 aspect ratio;
60Hz Vertical Sweep;
15.750Hz Horizontal Sweep;
Non applicable to RS-170 or RS-170A standard.
Sound 400Hz sinusoidal (@ Pic. Carrier ±4,5MHz) FM-modulated ±15kHz deviation.
Composite Video, negative or positive going.
RF Channels @ 75 Ohms, unbalanced:
#2 - 55.25MHz
#3 - 61.25MHz
#4 - 67.25MHz
#7 - 175.25MHz
#IF - 45.75MHz
I hope get a schematic of this unit and I will place it here. As many rigs I have, this might be the unique place on the entire web mentioning something about ARPEN GERADOR DE BARRAS TV.