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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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2nd Feb 2016, 5:43 pm | #1 |
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Join Date: Jan 2009
Location: Ayr, South Ayrshire, UK.
Posts: 33
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Hi. My tusty Techtronics 465 has just failed, looks like a PSU fault.
On the diagram there are a a load of fuses in the the secondary of the mains transformer. There is an EHT fuse somewhere. I can only see one 1 1/4" glass fuse, where are the other ones? Dave |
3rd Feb 2016, 10:30 am | #2 |
Rest in Peace
Join Date: Jan 2009
Location: Ayr, South Ayrshire, UK.
Posts: 33
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Re: Tektronics 465 Scope
still looking for a manual with layouts most of the downloads don't have the board layouts
Dave |
3rd Feb 2016, 11:35 am | #3 |
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Location: Fife, Scotland, UK.
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Re: Tektronics 465 Scope
They may be fuses, Jim, but not as we know them...
Some fuses look like 1/8 watt resistors, some look like small ceramic cylinders with two pins out one end... about 10mm diameter. David
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Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
3rd Feb 2016, 2:22 pm | #4 |
Hexode
Join Date: Mar 2014
Location: Peacehaven, East Sussex, UK.
Posts: 278
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Re: Tektronics 465 Scope
It would be worth looking at the tants on the 15V rails as they can short. My 468 had this problem and the supply is very similar
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3rd Feb 2016, 2:53 pm | #5 |
Heptode
Join Date: Jun 2010
Location: Zurich, Switzerland
Posts: 538
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Re: Tektronics 465 Scope
Dave, what kind of 465 model do you have exactly?
The net gives you manuals in example minimum 4 versions: 465/A-B-M and DV44 Meter-Modul... Other tema, that Tektronix didn`t publicated PCB(layouts), but you can find component population drowings in all me knowed SMs. Greetings Karl |
3rd Feb 2016, 2:57 pm | #6 |
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Join Date: Jun 2006
Location: Chard, South Somerset, UK.
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Re: Tektronics 465 Scope
The tall aluminium can electrolytics are favourites for PSU problems. However removing them for subsequent testing (and then possible replacement) is not an easy task. But with perseverance, it can be done. You do need a really hot iron, though.
Al. |
4th Feb 2016, 8:27 pm | #7 |
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Join Date: Jan 2009
Location: Ayr, South Ayrshire, UK.
Posts: 33
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Re: Tektronics 465 Scope
my 465 is a standard 465 the flat chassis mounted power transisor near the Eht suppy has very low votage, it is one of three flat pwr transistors I think this is the 5V supply but not sure
still need a circuit with layouts I can't find a circuit or layouts of the boards Dave |
4th Feb 2016, 11:30 pm | #8 |
Heptode
Join Date: Jun 2010
Location: Zurich, Switzerland
Posts: 538
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Re: Tektronics 465 Scope
Dave, you can find a 30MB file here_or here_I think my copy is the same...
Check please the circuit & placement matrix between pages 235-240. On my copy is part locator relative bad to read, but +5V Transistor is a Darlington_Q1556,hase a code for parts/grid locator=3F. On page 236, find it please over C1562, the left side "big electrolytic" in a group of 5 pcs... I wish sucessfull rep! Karl Last edited by karesz*; 4th Feb 2016 at 11:36 pm. |
7th Feb 2016, 6:35 pm | #9 |
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Join Date: Jan 2009
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Re: Tektronics 465 Scope
HI , thats a great manual , I notice the EHT inverter has 25v on it and oscillates but the neons used a shunt regulator do not light
I suspect the EHT transformer, it looks difficult to get to located under the interface board fixed with nylon screws still tying to find the EHT dide I think it may be inside the metal can with the transformer |
8th Feb 2016, 10:32 am | #10 |
Hexode
Join Date: Mar 2014
Location: Peacehaven, East Sussex, UK.
Posts: 278
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Re: Tektronics 465 Scope
the EHT multiplier is with the transformer and it's hard to get at. when you remove the Y board be careful to unsolder the 2 resistors from the Y1 &2 attenuators.
if you have a suitable meter there is a -2450V test point on the pcb |