Thursday, 23 July 2015

ZX Spectrum +2 Video Ghosting Fix


Another vintage computer to take a look at, this is a 128K +2 which was made by Amstrad. They made a few mistakes on this model including installing transistors upside down (issue 3 only), mixing the audio with the composite video and a ghosting problem with certain colours again with composite.

You can avoid the ghosting / poor image problem simply by using a RGB scart cable but composite cables are far easier and faster to make. :)

How to separate the audio from the composite video has been covered many times and is covered in this very handy pdf ZX Spectrum 128K video fixes and video cables.pdf so I won't go over it again.

The ghosting fix on the other hand is quite a recent discovery by JoulesperCoulomb on youtube although I found out about it from GadgetUK164's video again on youtube.


Basically all you need is a 15uH inductor and two ceramic caps (20pf and 68pf). Connect the inductor to pin 8 of the video encoder join the two caps in parallel and connect one end to the inductor and the other to pin 17, no more ghosting.

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