Thanks David, Craig and Jeremy.
I initially thought of having a simple way to estimate NF of Norton amplifier and other amplifiers. But seems, what is worth learning should be worth learning well.
I made the Noise source here (Fig. 5) Not current source
http://www.w1ghz.org/noise/noise99.pdf
On the Spectrum Anlayser, the noise rises by 9dB (including 15 dB pad).
Thru hole, dead bug. Noise peaks at 7.5Vdc.
Quote:
Originally Posted by G0HZU_JMR
I think your Siglent spectrum analyser has a noise figure of about 13dB with the preamp on. This isn't low enough if you want to be able to make good noise figure measurements. The other issue with your Siglent analyser is that its internal preamp could be prone to overload damage.
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Yes I noticed this for an amplifier yesterday and stopped. Please how did you get 13 dB ?
From the 1st image, 10 MHz - 1 GHz, 18 dB ? Is this what it means? (NF of Pre amp) not sure
Quote:
Originally Posted by G0HZU_JMR
My advice would be to make an external wideband preamp for the Siglent analyser. A good compromise would be to have a preamp with about 25dB gain and 3.5dB noise figure, then follow this with a protection limiter, then select 10dB internal attenuation in the Siglent analyser and then turn on the Siglent internal preamp.
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Will this guy do the job?
https://www.farnell.com/datasheets/2342538.pdf
Also, don't know what that limiter is
Meanwhile, I got a cheap laser printer last week to do Pcb for SMD soldering.
Starting with this
Thankssss
Any suggestion/advice, highly welcome