Microlighters

where can we get an encoder calibrated in cape town?

Mike, I'm sure you already know this but it might be worth mentioning that altitude encoders are calibrated to a pressure altitude of 1013 hPA /29.92 In. Hg... and obviously won't correspond or match the altimeter reading exactly if the Kollsman window setting is different e.g. for a QNH setting below TA.

Probably still doesn't answer your question though - sorry

thanks Learjet - ours is registering 2000' above the altimiter