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Identify Motorola Transistor

tangerame

May 9, 2010
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I have done considerabl repair on electronic circuits but mostly tube. Now I have a great bargain in a piece of HP Test Equipment that is partially working. The DVM Option to this counter an HP 5823a is not working. Opening the case and applying power there is smoke coming from one particular component. Looks like a small TO black plasti9c with a small mounting tab/heatsink TO-200 or 220? Anyway the markings are clear there are two of these similar components near to each other. The markings are as follows:

M (Motorola M symbol) 426 then below 4-514
M (Motorola M Symbol) 013 then below 4-514 (EBC markings on tab)

At first I thought this was a three temrinal regulator Know I'm not sure. The 426 is the one with the smoke and it apparently has already been replaced. Perhaps this is a complementary pair??

Can anyone identify these components?


Tony WA6LZH
 

Resqueline

Jul 31, 2009
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I'm sorry but that doesn't ring a bell (yet). I'm sure you're familiar with hp's 2 x 4 digit numbers - starting with 18 or 19. A picture or a drawing might help though.
 

shrtrnd

Jan 15, 2010
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Without a picture, you probably need a better physical description. I don't have a schematic on this unit. EBC indicates emitter/base/collector of a transistor.
That would make your device a 1854-0514 (equivalent to MPS-U02). But it's not a TO-220 pkg, it's a Motorola Type 152 Case (Shorter than a TO-220). If this sounds like a
description of your device, this is probably it. They are common as a MPS-U02, running about $6 apiece.
If you've got a full TO-220 Pkg, you have a different device.
The 1854-0514 original is obsolete, and you'd pay through the nose if you found one.
I did the best I could, with the info you supplied.
Good Luck
(The 3-digit numbers you're referencing, are the date code)
 

tangerame

May 9, 2010
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Shrtrnd I think you're on to it. This is the same case like a to-220 but only shorter. There are two of these following a small transformer on what appears to be a power supply type of circuit. I found the bad component by it's smoke! Is there a list of hp part numbers out there? This is my first HP test gear and I'm impressed.


Thanks so much,

Tony
 

shrtrnd

Jan 15, 2010
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I got mine over the years from HP Bench Notes as they obsoleted their parts, but there are a half a dozen good ones on the web. Google 'Hewlett Packard Cross Reference to JEDEC', I just checked and a reasonably complete one is 'HP Cross Reference Michael A. Terrell'
Hewlett Packard was the Rolls Royce of test and measurement gear in the 1970's and 80's. Then they changed-over to Agilent, ...pretty and accurate, but not as well-made as the Hewlett Packard of old. I'd bet yours is the 1854-0514. Good luck.
Dennis NA8U
(Hewlett Packard part numbers are 'xxxx-xxxx', when device was too small, they often cut the printed number on the device down to fit on the device. You knew from the package WHAT the device was, so you filled in the blanks. On your device, you know it's a transistor. HP transistors are first four digits 1853 or 1854 (NPN or PNP type), last four digits the device identifier. In last four digits, anything before the printed number, is a zero. 4-514 is 1854-0514. Just trivia, hope it helps).
 
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tangerame

May 9, 2010
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Shrtrnd thanks very very much for your help. I found the HP 185 list I was looking for and also a schematic/manual for the HP option I am attempting to repair.Guess finding the part or the part number is half the battle and maybe more.


Thanks!
 

shrtrnd

Jan 15, 2010
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Something made that transistor fry (again). Trace the circuit, and look for whatever is
causing excessive current through the transistor. Otherwise you're just going to be
making this repair again.
I've found only a couple instances over the years where the HP transistors were underrated in their test gear. If it looks like you just have a problem with the transistor, you might think about upgrading to a transistor that'll handle more current.
(But check your circuit for other damaged components first. Mostly I find leaking electrolytic caps to be the culprit in cases like this). Good luck
 

tangerame

May 9, 2010
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Right I just hope it is not the transformer. I should no more once I get the schematic. Thanks again.


Tony
 

manoj2madhav

May 22, 2010
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May 22, 2010
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hai,
please send your email ID to EMAIL REMOVED for 65,000 Transistor Equvalants Datasheet with a good software. It so simple to Identyfy the Transistor.
 
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