There is a filter on my Sigma Tek directional gyro at the port marked
"inlet". It's stamped with "Pandect Instruments Labs" and "Ref # 6A/5237".
It's a wafer type filter about 1 1/2" in diameter with another very small
screen about a 1/4" in diameter. The small screen is broken (has a hole in
it).

I cannot find this filter online.

Anyone know where I can purchase a new one?