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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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Thread Tools |
11th Jun 2019, 9:29 pm | #21 |
Octode
Join Date: May 2016
Location: Oxfordshire/Bucks borders, UK.
Posts: 1,604
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Re: Avometer Movements
No luck with this one.
The particular unit I am working on is incredibly insensitive. Even connecting directly to the movement is seeing such little activity. My current source is measuring the current flowing, so I know there isn't an open circuit. The movement moves a little when I leave the uA ranges and enter the mA ranges, but still not enough. Moving the shunt sees some change in activity. Introducing the magnets seems to do very little indeed. I'd have thought I would at least see something significant with such strong magnets around the movement?
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Avometer, vintage Fluke and Marconi collector. Also interested in vintage Yaesu and KW. |
11th Jun 2019, 10:41 pm | #22 |
Octode
Join Date: May 2016
Location: Oxfordshire/Bucks borders, UK.
Posts: 1,604
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Re: Avometer Movements
Some very strange results tonight. With the movement out, it does appear o/c! So I can't work out why there was some activity with it in the meter. Very unusual!
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Avometer, vintage Fluke and Marconi collector. Also interested in vintage Yaesu and KW. |
12th Jun 2019, 8:16 am | #23 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,081
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Re: Avometer Movements
My father had a Model 8 Mk II behave in a similar way. I think he came to the conclusion that there was a tiny flaw in the moving coil which was 'making and breaking' at random intervals. The physical disturbance of removal may have caused yours to separate properly. The coil COULD have corroded through somewhere,generating odd semiconductor-like effects.
Dave |
12th Jun 2019, 11:19 am | #24 |
Heptode
Join Date: Nov 2009
Location: Scarborough, North Yorkshire, UK.
Posts: 507
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Re: Avometer Movements
When an AVO magnetic system was re magnetised how was this achieved, also PMMUNRO mentioned artificial aging, how was this done ? I have in the past re magnetised fiends motor bike magnetos and left the rotating parts in position. Did AVO service centres leave the moving coil in position. I'm amazed at the knowledge and interest you people have on AVOs. There is certainly a special aroma and from me admiration for the people who made AVOs, they ooze quality . Ted
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12th Jun 2019, 2:07 pm | #25 |
Octode
Join Date: May 2016
Location: Oxfordshire/Bucks borders, UK.
Posts: 1,604
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Re: Avometer Movements
If that is the case, then I have a 9SX for parts, with a very good green NATO case, so all is not lost.
However I've still got a chance to prove the theory, as mentioned earlier I do have some others which are just a shade short of FSD, yet beyond what the shunt can achieve, so I can play with some of those.
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Avometer, vintage Fluke and Marconi collector. Also interested in vintage Yaesu and KW. |