Quote:
Originally Posted by OldTechFan96
The main problem at the moment is the lack brightness from the CRT. I'll start checking the CRT circuit. Especially around the blanking circuit. What does this do?
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As you will no doubt be aware, the trace sweeps the CRT from left to right. The sweep is driven by a signal from a ramp generator. Once the trace reaches the right hand side, the beam needs to be switched back to the left so that it can start the next sweep cycle. Although this switching back to the left happens very rapidly, if the beam were left turned on while this was taking place, it would leave an unwanted visible line across the CRT. The blanking circuit cuts off the beam as it is switched back from right to left effectively hiding this unwanted artefact.