FEATURES OF CONVERTER
The converter can generate the following
- Field frequencies of 25, 30, 50 and 60 Hz
- Number of lines between 16 and 830
- Number of active lines(lines with picture information) between 8 and 800
- Adjustable length of front porch, line sync, back porch and broad pulse.
- Number of broad pulses between 1 and 50.
- Sync height of 20, 25, 30, 35, 40, 45 and 50%
- Independent left and right crop
- Selectable equalising pulses
- Test patterns: Test card, Grey scale, Crosshatch, Cruciform, Black screen, White screen
FEATURES OF MODULATOR
- Frequency coverage 28.5 to 900 MHz in 5 ranges
- Frequency ranges and step:
28.5 to 56.25 MHz step 15.625 KHz
56.25 to 112.5 MHz step 31.250 KHz
112.5 to 225 MHz step 62.500 KHz
225 to 450 MHz step 125 KHz
450 to 900 MHz step 250 KHz
- Selectable negative video FM sound or positive video AM sound
- Selectable vision/sound carrier separation of 4.5, 5.5, 6.0 and 6.5 MHz or when in positive video AM sound mode the video and sound carriers can be set independently(Variable mode)
- Selectable picture/sound carrier ratio of 12 and 16 dB or fixed at 6dB when in Variable mode
- Can be used as a stand alone modulator
All Resistors, Capacitors and Inductors are 0805 size.
All Capacitors are ceramic multilayer types.
Where given manufacturers part numbers are given as examples alternative parts may also suit.
The PCB is double sided and measures 100 mm X 89.5 mm.
Link to uploaded Gerber files on PCBWay.
July 2021 I have updated the FPGA and PIC programming files.
The update allows the converter to convert from 525 lines as well as 625 lines. It automatically detects the input standard. Also included in the update are some test patterns. The patterns are applied before the converter so are available on all output standards.
Menu description (.pdf)
Circuit diagram (.pdf)
Component list (.pdf)
Component layout top (.jpg)
Component layout bottom (.jpg)
Front and rear panel legends (.pdf)
FPGA program file (.jic)
Microcontroller program file (.hex)