Tone generator and
Audio millivoltmeter |
![](voltm-1.jpg)
Rörvoltmeter = Vacuum Tube Voltmeter
Sinusvågsgenerator = Sine Wave Generator |
This was made from two different articles but I decided to
build them into one cabinet.
It is now more than 40 years since I put it together. |
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![](6203-tg1.jpg)
The Decade Tone Generator designed by my friend Jon Idestam-Almquist.
From an article in "Radio & Television" April, 1965. |
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![](6504-vm.jpg)
The Vacuum Tube Voltmeter, also designed by Jon Idestam-Almquist
From an article in "Radio & Television" March, 1963. |
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![](6504-vm2.jpg)
The voltmeters original appearance... |
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![](6504-vm3.jpg)
...and its interior. |
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![](voltm-2.jpg)
Inside my version... |
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![](voltm-3.jpg)
...close-up of the switches with components for frequency selection. |
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![](voltm-4.jpg)
The voltmeter part... |
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![](voltm-6.jpg)
Bottom view with all nice old resistors and capacitors. |
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![](tongen-thd.gif)
The THD is just below 0,1 % (< -60 dB) |
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![](../../images/copyr.gif) |