[Milsurplus] mystery diode

[Bob Camp]

Hi

Good catch !!! I gave up trying to sort through that document. 

Other than the package, it looks like a bog standard 60V silicon small signal diode. There’s more info that one might like to have, but I think that’s a safe guess based on what’s there. 

So, not a 1N34, go with a 1N914 / 1N4148

Bob

> On Sep 16, 2025, at 10:22 AM, Glenn Little WB4UIV via Milsurplus <milsurplus at mailman.qth.net> wrote:
> 
> PD9047 is line number 31 on page 246
> 
> Glenn
> 
> On 9/15/2025 5:08 PM, Jim Whartenby via Milsurplus wrote:
>> 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 <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 <https://prc68.com/I/Xtal1800.shtml#Diodes>
>> -- 
>> Have Fun,
>> Brooke Clarke, N6GCE
>> https://www.PRC68.com  <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>  <mailto:RAFANTINI at salisbury.edu>
>>> To: MMRCG<mmrcg at groups.io>  <mailto:mmrcg at groups.io>, Military Radio Collectors Association
>>> 	<mrca at mailman.qth.net>  <mailto:mrca at mailman.qth.net>, List Milsurplus<milsurplus at mailman.qth.net>  <mailto:milsurplus at mailman.qth.net>
>>> Subject: [Milsurplus] mystery diode
>>> Message-ID:
>>> 	<DM8P220MB04726E2DA952AB901FBAAB24B815A at DM8P220MB0472.NAMP220.PROD.OUTLOOK.COM>  <mailto:DM8P220MB04726E2DA952AB901FBAAB24B815A at DM8P220MB0472.NAMP220.PROD.OUTLOOK.COM>
>>> 	
>>> Content-Type: text/plain; charset="iso-8859-1"
>>> 
>>> 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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> -- 
> -----------------------------------------------------------------------
> Glenn Little                ARRL Technical Specialist   QCWA  LM 28417
> Amateur Callsign:  WB4UIV            wb4uiv at arrl.net    AMSAT LM 2178
> QTH:  Goose Creek, SC USA (EM92xx)  USSVI, FRA, NRA-LM    ARRL TAPR
> "It is not the class of license that the Amateur holds but the class
> of the Amateur that holds the license"
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