19.59025 kHz peak with a FFT analyzer

It could be the horizontal deflection frequency pf the CRT display. Some of the magnetic field from the deflection coils will escape through the front face of the CRT and can couple into your signal wiring. I have seen this effect in other makes of FFT analyzer. John

I have some Low frequency RF from the solar panels 'converter' that my neighbor had installed. Moving the wire around to find the source is an option?

Thanks. Indeed when I put my "debugging wire" near the CRT the pickup increases.

Arn't there more modern Stanford FFT's with a more modern, digital display?

Looks like you're somewhere in France. You might check if you're hearing VLF radio station GQD in England on 19.6 KHz which is used to talk to submarines.

Note that GQD can be heard in Germany: "What is the source of the ~19.6 kHz tone in the train stations around Frankfurt?"

Hint: Don't use unshielded wires in place of shielded scope problems. Unshielded wires are also known as antennas.

Correction. That should be: "Hint: Don't use unshielded wires in place of shielded scope probes".

Internal FFT is culprit only of it shows up to a shorted input.

RL

Sure, but I wanted an antenna just the time to try to locate the source.

Of course besides this I always work with shieded BNC's.

Self pollution? I was never fond of Stanford Research analyzers. The kicker was a case where that expensive thing could not find a noise peak in the audio range but my lowly netbook with a 1st gen Intel Atom CPU and 18(!) bit sound chip could clearly find it. Oh, and that netbook had cost me a fraction of what the client had paid for that analyzer. Their engineers stood there in disbelief. They initially didn't believe it. So I said "Slow down that fan over there with your palm and a rag and watch the peak on my laptop screen". One of them did ... "Oh S..T!"

Do you mean 8 bits? Most audio was 16 bits though?

Even back before 2010 most laptops sported 24-bit sound chips but mine had only 18 bits. That's why some of their engineers scoffed and thought I'd never find anything with that. Until I did.

SRS used 7-segment LEDs, spelling out letters!, way after everybody moved to LCDs.

Their pushbutton menus were crazy too.

Somebody once wrote a novel without using the letter "e".

Somebody should write a novel in 7-segment text.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

My first frequency counter I build used nixie displays and a 100 kHz crystal, TTL logic. late sixties, took it to work and used it there to calibrate some video equipment. That caused a stir! Then took it to the local HAM radio club and connected it the the superreg oscillator in a receiver You had to subtract the IF frequency, but fun!

No idea how many bits my 2013 Samsung laptop audio supports.

Yes, my old Z80 system soundcard I once designed, 8 bits IIRC:

These days, bit more RF added, and still in use:

It all depends. So much F35 noise here, audio from my Raspberry Pis, or TV..., or CDs and DVDs I recorded works perfectly.

There's apparently no IEEE or ANSI standard 7 segment alphabet.

Some seem to prioritize non-ambiguity which IMO makes for some illegible text:

Unless you're doing text entry also (hate your users) I don't think a 1 to 1 correspondence is required