Shared Projects by VideoLabGuy

This is a high gain video preamplifier suitable for use with an Iconoscope tube, like the 1846, 1848 or 1850. A more advanced hobbyist could adapt this amplifier for use with a vidicon tube relatively easily. This is one of a small set of boards for this project. There will also be a video sync generator, deflection board, video post process amplifier, and (probably) a power supply board. All in all, an interesting re-use of a 1943 RCA 1846 Iconoscope television camera vacuum tube. You can contact me through my web site, Labguy’s World dot com.

This board takes standard definition video and breaks it out into a buffered video output with gain, a horizontal and vertical scan ramps (for driving XYZ monitors) and several important video pulses (CMOS TTL levels) for the serious TV experimenter. With a couple of my other boards, it is possible to construct a complete television monitor using surplus electrostatic CRTs in the one to five inch screen size range. This board is smaller than v1 and is a lot lower in price. Fundamentally, the two circuit versions are the same. I recommend this version over my earlier for cost reasons.

This circuit is two 300 volt differential amplifiers and one single ended inverted (up to) 300 volt video amplifier for driving electrostatic cathode ray tubes ranging in size from 1 inch up to five inch in some cases. DC power input consists of -12 volts at less than 10mA and (up to) +300 volts at less than 10mA. Drive for defection can be single ended or differential drive ranging from 0 (up to) +5 volts. Out put can be voltages ranging from 0 (up to) +300 volts at each output. When perfectly balance, the differential will be 150 volts on each collector of the long tail pair. The video amp is simply one half of a long tail pair. If in phase output is desired, the user must provide the inverted input themselves. In the case of single ended drive to the differential amps, the undriven side is provided with +5V and the pot for that channel is adjusted to balance the amplifier. The end application of all of this is for supporting projects like the scope clock or my Tiny TV board for creating a simple monochrome video monitor.