Light Aircraft Association

I have a Gipsy Major which does not have screened ignition. Using my old 25MHz radio the background ignition 'noise' was fairly low-level and quite manageable. With the new 8.33 radio it is much more noticeable. It's not a problem on the intercom or when close to a ground station but when I am trying to receive transmissions that are weak it can make life a little difficult.

I have standard 14mm car-type spark plugs. What are the options for replacing my unscreened ignition with screened ignition?

Give Graham Keele at Hants Light Plane Services a ring: 01264-860056.
He is at Chilbolton and has recently assisted someone with using screened plugs on an Auster engine.
Tony

We use unscreeened plugs on our Gipsy Major and the newTrig radios reacted badly! We simply applied mesh sleeving externally from the plug base to the metal conduit pipe that carries the HT cables to the magneto. the mesh is earthed using a flex metal earthing strip running from a screw on the magneto case to each of the four mesh strips and connected using jubilee clips. The mesh is held in place by discrete cable ties, which we replace each time we service or change the plugs. It works.

Thanks John. And do you use screened plug caps of any kind?

sorry for delay in reply, been on holiday. No we don't use screened caps. we carry the mesh over the HT connector at the top of the plug, all the way to the plug base and cable tie it there. we obviously replace the ties each time we service the plugs.

Thanks John. At the risk of sounding thick, how do you insulate the mesh from the spade connector and the plug electrode? Do you have a pic you could send me?