[Milsurplus] mystery diode

[Jim Whartenby]

I was under the impression that Jacques has already done the research and found that the diode in question is a silicon diode.  His suggestion of a 1N4148 as a substitute appears to be a decent replacement with a higher PIV and faster reverse recovery time.  
Of course one can always do their own research and download the 1987 D.A.T.A diode book and make comparisons with what diodes they already have on hand.  See:https://dn790008.ca.archive.org/0/items/bitsavers_dataInc198ion54_123911610/1987_DATA_Book_Diodes_Edition_54.pdf Jim
Logic: Method used to arrive at the wrong conclusion, with confidence.  Murphy 

    On Monday, September 15, 2025 at 02:58:27 PM CDT, Brooke via Milsurplus <milsurplus at mailman.qth.net> wrote:   

   Hi Ray:
 
 Do you have a way of measuring figuring out the voltage across the diode.  For example if you know the meter sensitivity (for example: 1 mA at full scale is 1 Volt) then you would know the diode voltage when the meter was pinned at max reading.
 
 I have some data on diodes that are being sold as "1N34", but most are Schottky diodes.
 https://prc68.com/I/Xtal1800.shtml#Diodes
 -- 
Have Fun,

Brooke Clarke, N6GCE
https://www.PRC68.com
axioms:
1. The extent to which you can fix or improve something will be limited by how well you understand how it works.
2. Everybody, with no exceptions, holds false beliefs.
 -------- Original Message --------
  
 Date: Mon, 15 Sep 2025 01:04:08 +0000
From: Ray Fantini <RAFANTINI at salisbury.edu>
To: MMRCG <mmrcg at groups.io>, Military Radio Collectors Association
	<mrca at mailman.qth.net>, List Milsurplus <milsurplus at mailman.qth.net>
Subject: [Milsurplus] mystery diode
Message-ID:
	<DM8P220MB04726E2DA952AB901FBAAB24B815A at DM8P220MB0472.NAMP220.PROD.OUTLOOK.COM>
	
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Ok, so I have a very early AN/PRC-74 on the bench that has a shorted PD9047 diode (CR-15) that's used to develop the voltage for the tuning meter. the dam thing is very small and somehow don't think a 1N34 will take its place.
AI tells me that's a way obsolete part number and beyond its ability to come up with a replacement, anyone have any ideas? the tuning meter is somewhat important on the 74
This particular radio is serial number 606 and the PA deck is serial number 8! has strong output and in all other ways good.
you can see the circuit on page 186, figure 7-11 in the manual.

Ray F/KA3EKH 
 
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