[R-390] filters and foam

[Tisha Hayes]

I bet that the foam does have a mechanical isolating value for the filters
from vibration. Probably it is as much about centering in the filter body.

If you look at the more recent Collins mechanical filters they are a series
of rods mounted on a substrate so they do not benefit from mechanical
isolation yet they also exceeded the mil requirements.

One of the things I would of tried out would be to use that black
conductive foam that you see integrated circuits stuck in for ESD control.
One advantage I would see to that sort of foam is that if it was properly
trimmed you "might" be able to improve filter blow-by as the ESD foam would
provide RF shielding of the coils from one end to the other (like an RF
gasket).

-- 
Ms. Tisha Hayes/ AA4HA


*"neque est alter hujus universi locus quam anima"*
*('For there is for this universe no other place than the soul or mind')*
*-Arthur Schopenhauer*