These filters are designed as direct replacements for the
original mechanical filters which are now 50 years old and failing.
The Longwave filters look almost identical to the originals but in use they are
vastly superior, having steeper skirts and much
lower insertion loss.
Everyone who has purchased these filters is delighted with the way they perk up
their 75A-4 receivers. Experts such as
Howard Mills, W3HM and Ray Osterwald, N0DMS have endorsed the Longwave filters
and have stated in their
reviews that they are superior to the originals.