Modeline experiments

[murphyv310]

For me I set myself a task to get PC generation of old standards working. Up to very recently money has been very tight, so my converters had to go. I was prepaired to be without 405 for a few weeks or months if necessary. I already had a suitable PC and the channel 11 modulator so the only expense was a few components and the graphics card. I got this going for under a fiver initially and the biggest expense was the box for the band one rod pentode modulator at £20. A spare graphics was also purchased for under £5 including post.
The whole thing works a treat, some small anomalies initially have been sorted out as well. I also have access to other standards by a simple selection of the required standard.
With the shortage of new chips this makes PC generation of 405 a quick and cheap way to show pictures on an old set, there are many circuits of modulators around from simple to complex, free running or crystal control.
Have fun and enjoy an alternative method.

[Graham G3ZVT]

My modulator is based on an Early Television Foundation design and uses a pair of MC1374 ICs for sound and vision. No crystals, the free-running oscillators have proved to be no problem at all.