[R-390] R-390A Mechanical Filter replacement

[John Kolb]

On Thu, 12 Jun 2003, Bryce Ringwood wrote:

> Apart from the windings at each end of a mechanical filter - how do
they fail ?  Are the Kokusai type which use piezo crystals as bad or worse ?

The Kokusai MF-455-10AZ, used in the frDX-400 and similiar vintage
receivers has a failure rate perhaps approaching 100 % from the
foam in the filter decomposing. The good news is that they are
dasy to open and repair.
<http://members.cts.com/king/j/jlk/site/koku.htm>

I haven't heard of any problems with the transducers on the filter.

John