I have old style Honda generator that I purchased in the early 80 s that I still use. It has a freq meter on it that started not working propely. On dismantling it I find the armature of the vibrating reed indicators I was held in place with foam sheet that has disintegrated. I removed the old crumbling foam, & replaced it with a small amount of neutral cure silicon. Once it was properly cured I re assembled it & it now works properly. They are driven by a 6V AC winding on the generators.