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Tek 2246 scope, need transistor

Hello: Upon removing the case from my 2246 scope, the case snagged on the heat sink of one of the transistors in the "VO Gain" section of the main PC board (not the processor board), breaking the leads of this transistor. The transistor is a round metallic 3-lead transistor labelled " Motorola logo, 0846, 8641". It is one of a pair and has a slip-on metallic heat sink attached. I have been unable to identify or cross-reference this transistor, and would appreciate any help in identifying (and hopefully obtaining) another pair of transistors. Thank you in advance Todd K4RR

Reply to
todd
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todd wrote in news: snipped-for-privacy@q75g2000hsh.googlegroups.com:

All I could find online was the US military PN for that part; 6625-01-275-

4766

The TEK PN is;151-0846-00

8641 is the mfg.date code.(your scope was probably built in 1986-87.) 
--
Jim Yanik
jyanik
at
kua.net
Reply to
Jim Yanik

innews: snipped-for-privacy@q75g2000hsh.googlegroups.com:

Here is a site advertising TEK spares (including Hard to find). This may help you further.

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Regards,

Ravi.

Reply to
moghe.family

snipped-for-privacy@mtnl.net.in wrote in news: snipped-for-privacy@i13g2000prf.googlegroups.com:

I already checked it,no luck. I suspect IF you could reach a TEK service person,you could get a cross reference for it.They have all that data on the company intranet.I wish I could have retained my access to it!

Best chances of success would be the DC field office.

--
Jim Yanik
jyanik
at
kua.net
Reply to
Jim Yanik

I got this hit for Tek semiconductors:

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Also, I checked a Tek IC reference I had but of course discretes are absent.

If you cannot locate real spares and if the other transistor of the pair is good, determine its characteristics (curve tracer, test bench setups, etc.) and shop for equivalents.

Regards,

Michael

Reply to
msg

-Go to http:\\groups.yahoo.com

-register

-subscribe the "TekScopes" group (copy and paste the name, there's a group whith a similar name)

-when you can access it a search for Mr. Yanik's ref: 151-0846-00 finds several threads.

some quotes:

" the Tek cross ref says these are 2N3866A NPN RF power transistors in a TO-5/39 can, but this part does not work when installed in the scopes, and the manuals say there is trouble with any transistor that does not have the base connected to the case."

" These were a custom Tek mod of the standard part. If you don't use the correct part you will have all sorts of problems with frequency response and oscillations as you move your hand or the cover near these parts (been there - done that)."

So it looks like you have to find an original... Best Regards

Steve Sousa

Reply to
Steve Sousa

Perhaps the broken leads can be repaired on the existing part? How about finding a TO-92 case transistor with very close specs and build a shield around it connected to the base?

Reply to
James Sweet

"James Sweet" wrote in news:Ophai.21$pd5.18@trnddc02:

did the part that broke off your scope have it's base connected to the case? I don't recall that for the 2246.

2N3866A does not ring any bells for that 151-0846 part number,either. 
--
Jim Yanik
jyanik
at
kua.net
Reply to
Jim Yanik

I second Steve S's suggestion. The TekScopes group membership are numerous and very helpful. Members include some Tek retirees. Much helpful info collected there. I'm sure someone has fixed your particular problem before.

To change settings online go to: (Yahoo! ID required)

This URL is also the "join" web page.

Good luck,

--
John English
Reply to
John E.

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