Looking for bench type DMM that can show dBu

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Majestic12

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Jan 10, 2011
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Germany
Is there any bench type DMM in the "a few hundred euro / dollar range that can directly show me an AC input voltage converted into dBu?

All those units I have checked so far can show dBm values (1mW into whatever you specifiy as your impedance), but I would only like to have a display that shows me the dBu value referencing to 0dBu = 0,775V

I sometimes have to make precise alignments of audio switching gear and it's always a bit of PITA to calculate the correspondng voltage values for each dB step I want to have.
 
Unfortunately, I don't know any cheap ones. But how about using one equipped with a serial port and writing a small application for the conversion that runs on a host?
 
You could always get one that reads dBm and just add / subtract the offset (which you will need to calculate only once per output impedance) to get to dBu
 
Majestic12 said:
Is there any bench type DMM in the "a few hundred euro / dollar range that can directly show me an AC input voltage converted into dBu?

All those units I have checked so far can show dBm values (1mW into whatever you specifiy as your impedance), but I would only like to have a display that shows me the dBu value referencing to 0dBu = 0,775V
I would think units that show dBm are in fact displaying voltage, not power; in that case, dBm=dBu.
That is what you want, actually.
 
I have an HP400 FL and the day I got it my life changed...

It's not selectable as to loading or dB scales, but it reads dBm as 0.775V into 600 ohms, it's easy to read and easy to use...

And there is an output amp that plugs into your oscilloscope scope so you can see the input on your scope...

They can be had for pretty cheap, just make sure to get one from someone who knows it's working and accurate - they are all getting pretty old these days...

Here is the manual and some info on different models:

http://www.gellerlabs.com/hp%20400fl.htm
 
The old trusty Fluke 8060A can display dBu. They can be had cheap on the bay. I retired mine but I got it for around $75. I sent it in to a calibration lab. That was $50. It's a great meter.  The display can go bad so make sure it's good. Also make sure it looks like it hasn't been abused for 30 years.
 

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