VLF MD with digital signal processing : Bee-Buzz 1

[Aziz]

.... a better external sound card is something like the ARTURIA minifuse 1 & 2 .... Soundblaster is rubbish as you may have discovered.

The minifuse 1 is possibly a lot cheaper than the Soundblaster top model too.

The minifuse 2 has dual 24 bit stereo codecs. ( and alot of other stuff that trashes the soundblaster product ).

Noise floor is below -130 db up to 96 Khz at 192 KSPS.

I has an ASIO driver for windows and works fine ...

Nice. Could be interesting Moodz.
I'll take the old ones at home at the moment.
Aziz

[Aziz]

..
Take a break man.
..

Done!

I would like to improve my fancy super-duper-easy FFT ground balance method now. Trying to model the physical effects in LTspice but I don't get the real measured frequency response results from the past.

It seems, I have to make complete new measurements. And there we have it: Back to the roots and run into the circular direction.
Cheers,
Aziz

[moodz]

.... a better external sound card is something like the ARTURIA minifuse 1 & 2 .... Soundblaster is rubbish as you may have discovered.

The minifuse 1 is possibly a lot cheaper than the Soundblaster top model too.

The minifuse 2 has dual 24 bit stereo codecs. ( and alot of other stuff that trashes the soundblaster product ).

Noise floor is below -130 db up to 96 Khz at 192 KSPS.

I has an ASIO driver for windows and works fine ...

[dbanner]

There we have. I have massive problems in installing Sound BlasterX G6 drivers. Error Code 52. WTF!

But good news: No data loss. Only Win7 Apps are gone and must be installed once again.
M$ go to the hell! I'm not the enemy of my own computer. Let me install my fkn driver!

Put some fresh thermal paste on that poor CPU, it must be bone dry by now. And clean the thermal extraction fan while you're at it.

CPU running too hot can cause crashes, as you well know.

Aziz, somehow I get the feeling you are going in the circular direction. What are you trying to do, really? What is the point of all this? And you are given to using too many emoticons lately.

I think you might be in the midst of an anxiety attack/nervous breakdown. Take a break man.

Moodz is now poking fun at your expense.

Of course I am only joking.

[moodz]

Hey Aziz here is your detector in a suggested case to carry the computer.

[moodz]

Go with the force and change to Linux.

[Aziz]

There we have. I have massive problems in installing Sound BlasterX G6 drivers. Error Code 52. WTF!

But good news: No data loss. Only Win7 Apps are gone and must be installed once again.
M$ go to the hell! I'm not the enemy of my own computer. Let me install my fkn driver!

[Aziz]

Hi all,

two bad news!
1. The TX-coil only version doesn't work. I couldn't reproduce the measurements next day. So I very likely looked at the response from the wrong column (demodulator). Very likely from the response of the RX-coil nearby the TX-coil.
2. My Win-7 work PC has crashed with blue screen and damaged the boot sector today. I can not start the operating system anymore. Damn! All my project files haven't been backupped yet.

This could take some time...

[moodz]

Also, maximum power transfer only matters when you want to transfer maximum power. In the kinds of designs we do, we avoid that because it's just wasteful.

There are no ideal inputs ... everything draws a small current ( except maybe some future quantum circuits )

I was really referring to source impedance matching where the total source impedance when connected to the amplifier input is adjusted / matched for best performance noise wise.

I refer to power because power covers voltage and current whereas just saying noise voltage or current noise without reference to an impedance can be misleading. noise power is much a much nicer term.

( eg I have an amplifier with a 1 ohm input impedance and connect a 1 megohm resistor across it ... and compare to an amplfier with a 1 megohm input resistance and same resistor ... which amplifier will show the greater change in output noise ? )

The noise factor (F) is the same quantity expressed as a ratio rather than in dB – this ratio is of noise powers not of noise voltages.

[ArchibaldSTM]

I guess I'll unsubscribe from this topic --- it's reaching some kind of scientific dead end)))

[Aziz]

Not really, the RX current is miniscule compared to the TX current, and the coils are induction-balanced. That goes both ways.

But I would require more gain at the RX-coil. This would produce more amplifier noise at the end and there is no free lunch.

[Aziz]

Hi all,

you know I like crazy experiments. Something a serious engineer would never do.
What about pure impedance measurements on the TX-coil side?
We have the choke L1 and the TX-coil at the transmitter side. A VLF/LF dual frequency detector without an RX-coil? No IB-design. No pre-amp required. Simple coil design.

Oh well, I have put the choke L1 at the center of the TX-coil and measured the impedance change on the TX-coil.
Indeed, not bad results. We could also take the voltage at the choke L1 and measure it's own impedance change too.
The coil coupling coefficient between TX-coil and choke L1 is low (k=0.1 .. 0.2) as the choke is smaller in diameter.

This brings an interesting application. A concentric TX-coil with smaller choke (half diameter) at the center position.
This is for sure interesting to investigate and invest some time.

Cheers,
Aziz

[Aziz]

It's crazy...

I've got two big water bubbles on my fingers.
The final choke has 1135 µH inductance, 0.567 Ohms series resistance and weighs total 170 g (including the hansa plast plastic core). I don't to intend to get more water bubbles so I will take the choke for further experiments.
Cheers

[ArchibaldSTM]

500 g 1 mm copper

It's crazy...

[Carl-NC]

RX current sensing would produce much TX - RX coil interaction.

Not really, the RX current is miniscule compared to the TX current, and the coils are induction-balanced. That goes both ways.