Does anyone know how an Amphenol 75-MCIF jack looks like?

Looking at the panel of my Hallicrafters HT-40 transmitter, and having
determined that its diameter is smaller than that of a standard 1/4" inch jack,
I though it was a Collins-style microphone jack.

I tried with that but it does fit. It must be even smaller.

Any suggestion?

Thanks and 73

Tony I0JX