I'm wondering if anyone can help ID the component in the red box as well as the IC right next to it. I suspect that they are a diode (the tapered end might indicate polarity?) and some kind of Opamp respectively. This board is pretty old. It came out of an aircraft radio for a Cessna 150.
I tried googling "National Semiconductor JR56AB" and other variants for the IC but absolutely nothing came out of it.
I haven't physically seen the board yet. My friend just sent me the photo. Otherwise I would be doing some DMM tests on it.