Just saying Hi!

[ManuelDiaz]

Hi!

My name is Manuel, I'm Spanish although I live in Germany, I'm a computer engineer and for some time I've been interested in nuclear physics as one of my hobbies. After getting some geiger counters, assembling russian tubes into others and the usual things people like us does, I thought my next step would be to assemble a Gamma Scintillator. With the help Luuk (I thing he's well known around here) of some folks on the Environmental Radiation Monitoring Network group on facebook and the yahoo list, I am on my way to start getting some measures.

My GS1100A arrived a week ago (after being hijacked by German Customs :D) and now I am trying to make everything work. By now I am focused in two things: Getting a cleaner audio signal (I think that most of my problems getting the detector to work are related to the sound card, as even when I can hear a more intense crackling when the detector is approached to a radioactive source, the sound is not as the one that Steven gets on the demo video) I have already ordered the DeLOCK sound card that Steven recommends in other post which I think should meet the requirements; and preparing a good shielding to isolate the background.


And that's it! I'll be excited to share and discuss all my discoveries with you, and I am already documenting the process I am following in order to be able to prepare a document that might help other newcomers!


Thanks!
Manuel.

[Sesselmann]

Hola Manuel,

Welcome to the forum..

Good luck with your GS-1100A, if you have a noisy audio signal it may not be the sound card, it could also be your USB power or possibly a faulty cable. See my other post on faulty BNC cables (I can't recall if I supplied you with a BNC cable or not).

Use only quality BNC cables with solid polypropylene core and proper braid.

Steven

[ManuelDiaz]

Hola Manuel,

Welcome to the forum..

Good luck with your GS-1100A, if you have a noisy audio signal it may not be the sound card, it could also be your USB power or possibly a faulty cable. See my other post on faulty BNC cables (I can't recall if I supplied you with a BNC cable or not).

Use only quality BNC cables with solid polypropylene core and proper braid.

Steven

Hi Steven and thanks.

No, the GS1100A came with no BNC cable. I'll check if I can get another bunch of cables to see if that's the problem. Any BNC recommended? I need to order online as I can't find them anywhere in stores in Germany (maybe I am looking at the wrong places...)

I also thought about the USB power, but it seems to be ok (I tested it without anything connected to the USB ports, and with the external power cable connected to the laptop) But I can also try to connect the GS to an external power supply (I guess a normal phone charger of 5V 1A should be ok for this)

Anyway the usb sound card should arrive today/tomorrow, so that's another step in the test!


Thanks and kind regards,
Manuel.

[Sesselmann]

Manuel,

Any good quality RG58/U or RG174/U 50 Ohm cable is good, and it should not be longer than 1 meter.

Phone chargers are not all good, original iPhone chargers are okay but any of those cheap Hong Kong chargers are useless. Most PC and Mac usb ports deliver reasonably quiet power.

Steven

[ManuelDiaz]

Manuel,

Any good quality RG58/U or RG174/U 50 Ohm cable is good, and it should not be longer than 1 meter.

Phone chargers are not all good, original iPhone chargers are okay but any of those cheap Hong Kong chargers are useless. Most PC and Mac usb ports deliver reasonably quiet power.

Steven

Thanks Steven, I had a bunch of RG58, but I have ordered a RG174, as I suspect my RG58 might not be of a good quality. I have a Samsung charger (original) that delivers 5V 1A. Is 1A within the GS1100A range or is it too much amperage?

I still believe my big issue is with the sound card. I went for the DeLock you recommend in another post (costs 12 euro in german online stores) So if that doesn't work at least I'll know the issue is not with the soundcard.

[Sesselmann]

Manuel,

I have a Samsung charger (original) that delivers 5V 1A. Is 1A within the GS1100A range or is it too much amperage?

The Amps won't matter the GS will only draw a few hundred mA even if the power supply can deliver 100 Amps, the critical part is noise filtering, because a noisy supply will send ripples through the preamp.

The noise should be below 0.03 arbitrary units in PRA, you can check this by running a spectrum with zero pulse height threshold, the noise will produce a big peak on the left hand side and it will be easy to see where the noise needs to be cut off.

If you can get the noise below 0.03 arb.u the limitation of your spectrum will be your detector and not the equipment.

Steven

[ManuelDiaz]

Manuel,

I have a Samsung charger (original) that delivers 5V 1A. Is 1A within the GS1100A range or is it too much amperage?

The Amps won't matter the GS will only draw a few hundred mA even if the power supply can deliver 100 Amps, the critical part is noise filtering, because a noisy supply will send ripples through the preamp.

The noise should be below 0.03 arbitrary units in PRA, you can check this by running a spectrum with zero pulse height threshold, the noise will produce a big peak on the left hand side and it will be easy to see where the noise needs to be cut off.

If you can get the noise below 0.03 arb.u the limitation of your spectrum will be your detector and not the equipment.

Steven

Well, got the DeLock sound card today... and it´s made a huge difference!



This is an spectrum of a Cs137 spark gap, with no shielding at all of course, but at least the 662 and 32 kev peaks are clearly visible amongst the background trash!

[luuk]

Hi Manue,
Nice spectrum did you made that with the CsI(Na) crystall?
Luuk

[ManuelDiaz]

Hi Manue,
Nice spectrum did you made that with the CsI(Na) crystall?
Luuk

Exactly luuk! Everything starts to work out! :) thanks for all your support. I'm writing down all the construction process, and I hope to finish the document before going on my honey moon (end of the month)