I looked up the diode in my very old GE sub manual and every diode with a PD in it was a zener.  The last one in my books was a PD6057.
I tired to send this email 2 times and the QTH server kdiced it back as spam.  Trying just a 'reply', removed most of the traffic.

Charlie in NC

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   1. Re: mystery diode (Glenn Little WB4UIV)
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   3. Re: mystery diode (Jim Whartenby)