[Milsurplus] 400 Hz transformer (FL-5, MT-31C)

[Mike Morrow]

Brad wrote:

> ...what is Radio Filter FL-5-F (order 514-WFSCPD-42) used with,

It's a common high impedance audio filter used with aircraft range receivers to pass the 1020 Hz A-N range signal while filtering out most other audio signals.
 
> and Bendix Tuning meter MT-31C?

It plugs into the front panel of the Bendix TA-12 series of transmitters to measure either PA or driver cathode current, depending on which of the two jacks it is plugged in to.

Mike / KK5F