I measured input voltage and it is 24 V which is OK but output signal is 1.6 V. I guss at least it should be 1.8 V. Anyone has experiensing with repair of this gauge or is there any electronic schematic around?
Steve
Edwards AIM-S-NW25 active gauge no responce?
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Chris Bradley
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Re: Edwards AIM-S-NW25 active gauge no responce?
Could be a number of things, but generally they are built to be 'non-serviceable', so no schematics freely available. If you wish to delve into the electronics, then you will have to prise apart the plastic parts to investigate, and you will inevitably break the container and have to effect some sort of repair after. You might get lucky at probing the various components for a fault - they are built with the larger size of surface mount components that are a little more 'readily dealt with' by diy means.
But don't jump to the conclusion it is the electronics just yet. If you are getting a 'fault' signal out then something is stirring within!! Instead, firstly remove the magnetron chamber and check all the connections and alignments to the back connections. I seem to recall the connection to the electronics is a spring type thing - check it is there (!) and or not twisted by the last owner (presuming it is some sort of 2nd hand offering you've found) - and the pin connection into a ferrule in the electronics by the anode. This is done simply by gripping the housing on the grey ring part, with the ribs on it, in one hand and the flange in the other and rotating the two parts. Then they slide apart. It is like a big bayonet fit.
You can disassemble that flange part further, and clean up the interior parts, and there is a kit with new anode, and other parts, that you might get too.
But don't jump to the conclusion it is the electronics just yet. If you are getting a 'fault' signal out then something is stirring within!! Instead, firstly remove the magnetron chamber and check all the connections and alignments to the back connections. I seem to recall the connection to the electronics is a spring type thing - check it is there (!) and or not twisted by the last owner (presuming it is some sort of 2nd hand offering you've found) - and the pin connection into a ferrule in the electronics by the anode. This is done simply by gripping the housing on the grey ring part, with the ribs on it, in one hand and the flange in the other and rotating the two parts. Then they slide apart. It is like a big bayonet fit.
You can disassemble that flange part further, and clean up the interior parts, and there is a kit with new anode, and other parts, that you might get too.
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John Futter
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Re: Edwards AIM-S-NW25 active gauge no responce?
Steve
The gauge not striking is usually bought on by the internals being dirty --diff pump oil leaving an insulating layer of crud or worse backing pump oil
Clean the internals of the gauge first.
This will require disassembly you will need a set of circlip pliers and some 600 grit carborundum paper.
Be careful not to knock off the little sharp tab near the bottom that helps initiate the plasma.
All parts should be bright a shiny before reassembly
The gauge not striking is usually bought on by the internals being dirty --diff pump oil leaving an insulating layer of crud or worse backing pump oil
Clean the internals of the gauge first.
This will require disassembly you will need a set of circlip pliers and some 600 grit carborundum paper.
Be careful not to knock off the little sharp tab near the bottom that helps initiate the plasma.
All parts should be bright a shiny before reassembly
Re: Edwards AIM-S-NW25 active gauge no responce?
Sometimes you can get them to strike by tapping them with the screw driver handle, I have seen this done numerous times (@Varian). I would like to think this may be "vibration assisted electron emission " (lol) but suspect it has something to do with the moving field. I would not whack it into submission though, no sense flogging a dead horse.
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Chris Bradley
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Re: Edwards AIM-S-NW25 active gauge no responce?
Steve, why are you so convinced the electronics have failed, when it is the electronics that is giving you the 'error' signal?