Simpler PI...

[Aziz]

It seems, that I have been conned with my BC550C transistors. It looks like, that a f$kin ba $ tard has relabeled them (clearly visible!!!).
I have to buy a new batch of them and test them. I think, I've got a cheap relabeled BJT's.
That would probably explain the poor noise performance.
Aziz

My so-called "BC550C" is performing like a BC547C! It will probably perform like a BC546 or other cheap NPN too.
Ba $t @ rd$$$$$!

[Aziz]

It seems, that I have been conned with my BC550C transistors. It looks like, that a f$kin ba $ tard has relabeled them (clearly visible!!!).
I have to buy a new batch of them and test them. I think, I've got a cheap relabeled BJT's.
That would probably explain the poor noise performance.
Aziz

[Aziz]

Ok sinclairuser,

I just have tested the TL071 (CP) (replaced the NE5534). No measurable difference to NE5534 at all. You can take (almost) every op-amp. The noise contribution to the transistor stage isn't much relevant.
Aziz

[Aziz]

hi aziz good work man, take a look at the ti tle2072, were using it as a 072 replacement and so far it is better, 3 reasons are dip pack, direct replacement, but more important its on sample at the moment so users here can get free samples.
check out the d sheet.

Thanks for your hint sinclairuser. But we are using a bi-polar technology not j-fet. We are using low impedance (low resistor) signal sources (coils have a very small resistance). BTW, the tle2072 has much much more input noise density.
Cheers,
Aziz

[sinclairuser]

hi aziz good work man, take a look at the ti tle2072, were using it as a 072 replacement and so far it is better, 3 reasons are dip pack, direct replacement, but more important its on sample at the moment so users here can get free samples.
check out the d sheet.

[Aziz]

Some older RF transistors, like 2N4427, 2N3866, MRF 237 style are also good candidates.

Thanks Tepco, could be a trial worth.

BTW, the 2 x BC337-40 is achieving 0.8 nV/sqrt(Hz) with NE5534 as op-amp. You don't need expensive op-amps. The NE5534 will do it very well. I'm right now below 50 Cents for the ultra low noise core parts (2 x BJT + op-amp). It's going to be ultra low cost as well.

Cheers,
Aziz

[Tepco]

Some older RF transistors, like 2N4427, 2N3866, MRF 237 style are also good candidates.

[Aziz]

2 x 2N2222

My new BJT favourite: 2N2222

Can you believe me, when I state, that two parallel 2N2222 are performing like a LM394 (both transistors parallel)?
They achieve ~ 0.72 nV/sqrt(Hz) input referred noise density (measured).

I'm very close to my goal. The "World's Quietest Metal Detector Front-End"(c)(r)(tm). *LOL*


Cheers,
Aziz

[Aziz]

Aziz, have a look at mje13007:

http://www.beis.de/Elektronik/LNPreAmp/LNPreAmp.html

Thanks ppodg, I knew it. The MJE13007 is also on the wish list.

BTW, forget the BC550C. Too noisy. The BC337-40 will do much more quiet.
Aziz

[ppodg]

Aziz, have a look at mje13007:

http://www.beis.de/Elektronik/LNPreAmp/LNPreAmp.html

[PATCHES JUNIOR]

i would say
9. Yep, you have won the great prize! (one virtual 6-pack of my favourit köstritzer black beer)

because you are some kind of a crazy rocket scientist and you do what you say

No, I say Aziz has this time made a actual detector, not some simulation done on a computer program. Show that I am right Aziz and post up the detector that only took you 2 days to make. A picture would show all the naysayers how you are the real thing.

[bernte_one]

i would say
9. Yep, you have won the great prize! (one virtual 6-pack of my favourit köstritzer black beer)

because you are some kind of a crazy rocket scientist and you do what you say

[Aziz]

Ok guys,

I have built it. No smoke.

The betting office has just opened.
Who is saying/betting:
1. It works but bad. No benefit.
2. It works a treat.
3. No, it can't work. Never ever!
4. Aziz!, please give up the stuff!
5. The total thermo nuclear melt-down is coming..
6. Nice, but my amplifier works better.
7. You can't beat Mr. Candy! No way!
8. Aziz, go to the hell!
9. Yep, you have won the great prize!
10. You can't win the great prize! My d1ck is longer.
*LOL*

See the other forum for the first test results...

Cheers,
Aziz

[bernte_one]

only results count, watson

[Aziz]

Hi all,

we have actually a good soldering weather! It's raining here. I have powered up my soldering iron.
Let's squeeze out all that amplifier noise.

Oh man!, it's so quiet here. What's going on? Soldering the ultimate amplifier?
Cheers,
Aziz