This compact PCB simply replaces the existing RF modulator PCB in a Sinclair Spectrum 16k or 48k, either rubber key or "plus" case machines. We recommend that you remove the original carefully and put it in storage, in case you ever wish to re-install it for authenticity. The PCB outputs a composite video signal that is compatible with a large range of modern television sets.

The PCB itself is very simple, requiring just a few components to operate. Choose which of the three options you would like to use.

• Option 1 is an Inverted Emitter Follower recommended to me in an attempt to get a Dell UltraSharp 2007FP Monitor to work with a 48K Spectrum. Sadly, the monitor is extremely picky about it’s composite input and is well documented for it. In this instance it didn’t work. However, the composite mod works with all the other monitors I have tried it with.

• Option 2 is a simple NPN transistor and resistor mod. the NPN Transistor can be any general purpose device. I have used a BC547 in the past.

• Option 3 is a single 100uF capacitor which is seen to be the minimum required (Decoupling).

There have been many conversations around the need for other components with regard to the composite mod. Some say that it is not necessary at all and others say that, in case the monitor goes faulty or is very badly designed, it can feed voltage back to the Spectrum. I recommend you do your own research and choose the option that best suits you.

This board is not compatible with 128k models because it does not accomodate sound. For those models we recommend the correct cable from Retro Computer Shack.

This project is designed by Stephen Smith of projectspeccy.com and is reproduced here with his express consent! Visit Stephen's website for more useful Sinclair Spectrum projects and add-ons. Gerbers are available for free download from there.

If you wish to purchase this board as a kit, complete with components please visit us here.

Thanks for creating!