Need Help Identifying Diode - Page 1
Forum section: electronics / beginners

author: groinksan
author_rank: Contributor
timestamp: July 13, 2019, 11:18:39 am
content: I received a bunch of NOS diodes. For the life of me, I can't make sense of this diode. I'm trying to find the part number for it. I tried researching the colors, but Google has a mixture of results. The packaging appear to be military-like, so I suspect the part is MILSPEC. I opened one of the packets, and zoomed in on it with a microscope. The lettering only shows "C". Original packaging:5960-503-4034CE 78619SEMICONDUCTOR DEVICE, DIODE37-LYN-62A- 9/62Appreciate any help in identifying this part. Thanks!!!!

author: MagicSmoker
author_rank: Super Contributor
timestamp: July 13, 2019, 11:25:06 am
content: Most likely a 1N519 (Green-Brown-White color code) Silicon rectifier rated at 50V / 1.25A.Color codes for diodes were not entirely standardized, however, so you are right to be wary of such.

author: jmelson
author_rank: Super Contributor
timestamp: July 13, 2019, 03:01:17 pm
content: the numbers 5960-892-3417 and 5960-503-4034 are National Stock Numbers. But, these may be obsolete, I can't find them in several sites that supposedly list NSNs.I'm not surprised that Germanium diodes from 1962 would be too old to still show up there, but on the other hand the military keeps some REALLY old gear running.Jon

author: groinksan
author_rank: Contributor
timestamp: July 13, 2019, 11:28:01 pm
content: I just now ran the diode through my transistor tester, the attached image is the result. Hope this helps!

author: bob91343
author_rank: Super Contributor
timestamp: July 13, 2019, 11:39:03 pm
content: Yup it's a germanium diode. With only 0.4 V forward and so much leakage, it can't be anything else. I don't think it's 1N519 as that's silicon. So it's probably a house number, whoever'e house C is. Continental Devices? There were several like that. No that would be CD.

author: groinksan
author_rank: Contributor
timestamp: July 14, 2019, 04:52:15 am
content: Quote from: jmelson on July 13, 2019, 03:01:17 pmYou were on the right track. Because you mentioned that the "62" meant 1962, come to find out the stock number uses the older Federal Stock Number (FSN.):https://en.wikipedia.org/wiki/Federal_Stock_Number"5960" is the Federal Supply Classification Group (FSCG) code. The remaining seven digits are serial numbers.After the NSN replaced the FSN, one can possibly re-format the FSN to fit the NSN's format in case there were leftover inventory that had to be moved to the new system:NSN 5960-00-892-3417 and 5960-00-503-4034And sure enough, they work!https://www.iso-group.com/Public/Search_Results.aspx?ss=5960-00-892-3417https://www.iso-group.com/Public/Search_Results.aspx?ss=5960-00-503-4034NSN 5961-00-503-4034, 5961005034034SEMICONDUCTOR DEVICE,DIODEFederal Supply Classification: FSC 5961 - Semiconductor Devices and Associated HardwareNational Item Identification Number: NIIN 005034034Codification Country: United StatesItem Name Code: INC 20589Criticality(X) This item does not have a nuclear hardened feature or any other critical feature such as tolerance, fit restriction or application.Hazardous Material Indicator Code(N) There is no data in the HMIRS and the NSN is in an FSC not generally suspected of containing hazardous materials.So searching by the NIIN, it appears that this part is a 1N279. Based on what has been posted earlier, does 1N279 sound about right?It would be really cool if we come to find out that this part was meant to be used in some NASA equipment. 1962 was around the time the Apollo AGC was being engineered and built, and the core rope memory used these kinds of components.

author: MagicSmoker
author_rank: Super Contributor
timestamp: July 14, 2019, 02:36:06 pm
content: Always nice when the OP comes back to report what they found. The 9/62 being a date code does strongly suggest a Ge diode, though I believe - I'm not entirely sure - that Si diodes had already been discovered, if not put into commercial production, by that point.As for it being a 1N279... well, who knows? That's one unorthodox color code if so.

author: bob91343
author_rank: Super Contributor
timestamp: July 14, 2019, 05:10:59 pm
content: 1N279 is a strong possibility. 30 V 500 mA gold bonded fast diode.These would be great replacements for rf wattmeters and swr meters. Also for VOM rectifiers and radios.

author: groinksan
author_rank: Contributor
timestamp: July 14, 2019, 09:18:51 pm
content: Quote from: MagicSmoker on July 14, 2019, 02:36:06 pmI'm with you on this one. The databases could be wrong, or the databases could be assuming things. There's also a strong possibility that the FSN could have been used for a particular type of component, and could have a range of values. If I was repairing something, pulled this component out of the bag, I too would believe the color codes over the packaging.

author: MagicSmoker
author_rank: Super Contributor
timestamp: July 14, 2019, 10:07:57 pm
content: Quote from: groinksan on July 14, 2019, 09:18:51 pmA randomly pulled datasheet for 1N279 gives a leakage current spec of 1mA at 30V or 200uA at 20V, which is easy enough to verify with a variable power supply that goes up to at least 50V or so and a current-limiting resistor. Note that if you intend to use the diode for low level signal mixing or the like that a reverse leakage test can permanently increase its noise.

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: July 15, 2019, 01:08:48 am
content: The colour code might represent the Slash-Sheet number out of MIL-S-19500 (Standard Semiconductor List)

author: groinksan
author_rank: Contributor
timestamp: July 15, 2019, 02:54:27 am
content: Did more digging around.... I found two photos of another 5960-503-4034 diode (neither photos are mine.) The packing is from the same 1962 period, but it contains more information about the part in the pouch. In this case, the color bands match what is typed on the pouch - 1N279. What I'm taking from this is that the color bands should be indicating the value of the component.