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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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8th Sep 2013, 4:53 pm | #1 |
Pentode
Join Date: Sep 2011
Location: Consett, County Durham, UK.
Posts: 117
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AVO 8 Mk III Problem
Hi guys,
I recently picked the above meter at a local boot sale. Not surprisingly it did not work but I soon found that one of the 15M resistors had become detached. Having resoldered this back on again the meter now zeroes on all but the ohms times 100 setting, which when switched to this setting seems to simply switch off. Any ideas as to how I can fix this? Cheers, Gordon.
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Gordonc |
8th Sep 2013, 4:59 pm | #2 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,786
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Re: AVO 8 Mk III Problem
Have you checked the 15V battery?
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8th Sep 2013, 6:25 pm | #3 |
Dekatron
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,171
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Re: AVO 8 Mk III Problem
Hi Gordon, I probably have the manual for this one if you need it, as Paul said, check the 15v battery
Ed |
8th Sep 2013, 6:43 pm | #4 |
Pentode
Join Date: Sep 2011
Location: Consett, County Durham, UK.
Posts: 117
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Re: AVO 8 Mk III Problem
Hi, Ed,
I did not have a battery, so I taped together 5 new 3v button cells and put these in with a couple of nuts as spacers, which seemed to work. Could this be the problem? Gordon.
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Gordonc |
8th Sep 2013, 8:28 pm | #5 |
Dekatron
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,171
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Re: AVO 8 Mk III Problem
Hi Gordon, sounds like you've solved it and should have a permanent solution as the current draw is tiny.
Ed |
8th Sep 2013, 9:24 pm | #6 |
Pentode
Join Date: Sep 2011
Location: Consett, County Durham, UK.
Posts: 117
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Re: AVO 8 Mk III Problem
Hi Ed,
Unfortunately the problem occurs with the button cells in place! The meter zeroes on the ohms, ohms divided by 100, settings but not on the ohms times 100, where it seems to just switch off! Gordon.
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Gordonc |
8th Sep 2013, 10:55 pm | #7 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,786
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Re: AVO 8 Mk III Problem
The first thing to do is double check your work with the battery. Try hooking up a PP3 with croc clips - it won't work properly but the pointer should move.
I use 5 cheap CR2032 lithium cells in mine. If you are using alkalines such as AG13s they will only be 1.5V so you will need 10. |
8th Sep 2013, 11:04 pm | #8 |
Pentode
Join Date: Sep 2011
Location: Consett, County Durham, UK.
Posts: 117
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Re: AVO 8 Mk III Problem
Hi Paul,
I am using 5 CR2032 lithium batteries as you are, so I think it must be something else that's causing the problem. Gordon.
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Gordonc |
9th Sep 2013, 7:52 pm | #9 |
Dekatron
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,171
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Re: AVO 8 Mk III Problem
Hi Gordon, give me a ring and bring it over some time. I'll dig out my manual for it.
ed |
10th Sep 2013, 6:28 am | #10 |
Pentode
Join Date: Sep 2011
Location: Consett, County Durham, UK.
Posts: 117
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Re: AVO 8 Mk III Problem
Hi Ed,
Many thanks for the kind offer. I have a copy of the manual. I managed to download a copy. I think I have also managed to solve the problem. It appears to have been a fault with the probe leads. I changed these and hey presto, the meter now zeros on all 3 resistance settings! I also took advice from other forum members who suggested repeatedly pressing the cut out button a few times as it is self cleaning in terms of its contacts. Maybe this also helped. Gordon
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Gordonc |
14th Sep 2013, 11:51 pm | #11 |
Pentode
Join Date: Sep 2011
Location: Consett, County Durham, UK.
Posts: 117
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Re: AVO 8 Mk III Problem
To moderators,
The AVO is working fine now. Please close this thread. Gordon.
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Gordonc |