The Beehive

[BusyBee]

Neons are also quite noisy, but likely not very wide band.

A lowest capacitance zener (typically lowest power) has the better HF response.

Some filtering (most?) should be between the noise source and the amplifier to minimise distortion and maximise output.

I did come across the use of gas filled tubes. There were ones produced which had this as one of their uses. I have some neons but, apart from what you say, the operating voltage would be high.

With my initial designs I have a two stage amplifier following several similar designs I came across online. I was thinking of the filtering between the two stages. Where the signal is still low but not too low as to be possibly lost, to a great extent, in the filter.

For my first tests of the noise source though I will likely seperate things as I do have one of those 30dB wideband amp modules that come cheaply from China. With the noise source connected into it I would expect some kind of signal which can be measured out. It avoids dealing with two unknown quantities at once.

Also a peak reading or RMS AC meter will give a much higher reading than the level seen on a spectrum analyser with wide band noise.

I will see what I get.

Tracy