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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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10th Apr 2011, 3:06 pm | #1 |
Hexode
Join Date: Jul 2007
Location: Edinburgh, UK.
Posts: 344
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Tektronix 545B vertical output amplifier
Hi,
I am repairing a Tektronix 545B and have traced the fault to a transistor in the cathode of one of the output valves. The transistor is marked with Tek part number 151-127. Can anyone tell me what the commercial equivalent is for this transistor or know what the operating parameters are? thanks. ross |
10th Apr 2011, 3:14 pm | #2 |
Retired Dormant Member
Join Date: Nov 2009
Location: Weardale, UK.
Posts: 1,981
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Re: Tektronix 545B vertical output amplifier
I found this
Tek Part Number...Type..Polarity.......Specs.......Equiv Part 151-0127-00........Si......NPN...........Selected....2N2369 on here http://www.sphere.bc.ca/test/tekequiv.html Info for 2N2369 on here http://www.datasheetcatalog.org/data.../490431_DS.pdf Like I know anything about such things, but I hope that might help Chris Last edited by oldticktock; 10th Apr 2011 at 3:21 pm. |
10th Apr 2011, 7:09 pm | #3 |
Hexode
Join Date: Jul 2007
Location: Edinburgh, UK.
Posts: 344
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Re: Tektronix 545B vertical output amplifier
Hi,
Thanks very much for the information, I now know what I need to get. In the meantime I have found something in the junk box that works well enough for the time being but is not really good enough to give me the rise time that the scope is capable of. |
10th Apr 2011, 7:57 pm | #4 |
Retired Dormant Member
Join Date: Dec 2003
Location: North London, UK.
Posts: 6,168
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Re: Tektronix 545B vertical output amplifier
The 2N2369 is a very common device for high speed switching and amplification. There are also plenty of other devices that use the same basic die, some in plastic packages though I can't recall any specific type numbers at present. Possibly ZTX314?
I don't know what Tek were selecting, possibly matched pairs to give good DC balance or possibly hFe to give low base current. I suggest you just get some 2N2369 or 2N2369A or other similar devices and try them. The results should be pretty good. I vey much doubt if Tek were selecting for HF characteristics so if you still have poor risetime after fitting a replacement then the problem lies elsewhere. Unless you have a very good test generator it is actually very tricky to get a decent risetime measurement. |
12th Apr 2011, 12:20 pm | #5 | |
Octode
Join Date: Dec 2008
Location: Wincanton, Somerset, UK.
Posts: 1,757
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Re: Tektronix 545B vertical output amplifier
Quote:
John |
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14th Apr 2011, 7:15 pm | #6 |
Hexode
Join Date: Jul 2007
Location: Edinburgh, UK.
Posts: 344
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Re: Tektronix 545B vertical output amplifier
Hi John,
Thanks very much for sending me the transistor. It is really nice to see just how ready people are to help each other out on this forum. thanks everybody Ross |