[Lowfer] Core material on monitor cables

[Andy - KU4XR]

Hi all:

Can anyone tell me what type of material the cores are that 
you find on monitor cables, older printer cables, inside TV's,
and monitors that the wires run thru. They are black, and about
2/1-2 inches long, and about 3/4ths inch in diameter.

Secondly; would they be useful as core material to use at LF/MW
for receive purposes. chokes, baluns, isolation transformers ??

Thank you for your input;  **  73 to all  **



Andy - KU4XR - EM75xr - Friendsville, TN.
LOWfer Beacon " XR " @ 185.29866 KHz ( QRSS-60 )
Coordinates:  N:  35* 43' 54" - W:  84* 3' 16"
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