Steven Swift wrote:

I am restoring a 1937 BC-312.

A previous owner had installed a Collins mechanical filter in the 1st
detector stage (normally a coil with crystal phasing).

The Collins filter is part number 526-9395-00 and labelled "F 455 Z 7"

From google searches, it appears that this might be an SSB filter, but I
haven't found an exact reference.

Anyone know what this really is? I have to decide whether to "un-modify"
this stage or leave it as-is.

TIA,

Steve.
--


The F455Z-7, part number 526-9395-00 is a 455kHz Lower Sideband filter
with a 3dB minimum bandwidth of 1.7kHz.

The case should be a long "Y" style: 7/16" diameter, 2 1/2" long with
three solder terminals at one end, and two at the other. It may also be
equipped with a couple of different mounting options for surface or
feed-through mounting.

Dave