Gamma Spectrometry Forum

I have used just about every sound card MCA driver out there, and made quite a few of my own as well, so I think my judgment of Steven’s new GS-USB-PRO is reasonably sound. In my opinion, the GS-USB-PRO is by far the best sound card MCA bias adapter on the market.

From the moment I opened the box I was impressed with its professional appearance. Not that Steven’s previous adapters were shabby, but that this new revision of his popular GammaSpectacular is quite a step above the rest. I received mine (Thank you Steve) a couple of weeks ago and have had the opportunity to test it with a variety of detectors and different configurations before writing this review.

Besides the professional appearance, I appreciate having the ability to work with both single cable and dual cable detectors. While I won’t repeat all the specs here, I will mention that the GS-USB-PRO includes an external port for access to an internally adjustable potentiometer for HV. I found the high voltage range, stability and repeatability to be excellent. I personally would prefer to have a HV potentiometer with an external knob, however this really is unnecessary for those working primarily with a single detector setup. In fact it is probably more advantageous not to have a knob, in that it is much less likely that the voltage will change by accident. In any event, Steven includes a small screwdriver with the GS-USB-PRO for adjusting all the pots and setting the couple of dip switches as well, a nice touch. Oh, and having a quality sound card built-in to the GS-USB-PRO is brilliant. Just a single USB cable (included) makes it a snap to setup.

I also want to mention that when in the combined HV and Signal configuration (Single Cable Detector), the signal and HV are on the SHV connector. While it might have been easier if it was on the BNC, I understand Steven’s concern for HV going as high as 2000 volts on the BNC. Although most BNCs can handle that voltage, their design makes them inherently a risk for shock, since it is easy to reach the center conductor with exposed parts of the body. Since most single cable detectors I come across are BNC, I’m glad I had a SHV to BNC cable handy. If ordering a GS-USB-PRO for use with a single cable detector, don’t forget to get a SHV to BNC adapter or cable so you’re ready to go when the GS-PRO USB arrives.

There are a ton of useful features I still want to explore (see specs elsewhere), and I’ll get to those soon. I’m between quite a few projects and family time right now, however I wanted to get this quick review out there to thank Steven for his hard work and excellent product. Finally… a professional quality piece of equipment that even a hobbyist can afford.

Cheers, Tom Hall / Stuart, FL USA

Here are a few pics for now, with more comments and pics to come…

Here is a pic of 3" Bicron Well Detector using an Ortec socket with separate HV and Signal.

Wow Tom, thanks for the great review, couldn't ask for more than that ;)

Steven

You earned it all the way, nice job. Cheers, Tom

I had the chance this past weekend to fire up my new GS-USB-PRO. I am brand new to gamma spectroscopy so this was literally my first use of any type of spectroscopy hardware. I plugged everything in, adjusted the voltage (which is very easy thanks to the LED numerical display) and I was off. Windows 10 automatically installed the driver and I was rewarded by audible clicks.

Thre great thing about the ease of installation (at least for a new guy like me) is I now only have to worry about figuring out the software! That sounds like a no-brainer, but it wasn't all that long ago when installing hardware was a real chore.

Here's my first attempt with a CS137 source (unshielded). Now I need to figure all the settings to make it all line up. I know there's an equalizer in Theremino to make corrections, it's just a matter of spending time with the program for me.

Hi Steve,
good work and nice spectrum!
I've always used Theremino MCA with BaseLine Test activated; I've never used the new GS-USB, but I think it could be better to activate it, or at least you can try and see what happens.
I don't know the voltage you used, but you can try to lower it and increase the energy trimmer, this way the resolution should gets better.

Just got mine last night and took it for a very quick test drive with a school laptop. The results so far have been fantastic.
I am able to see peaks into the 3.5 - 4MeV range with my Scionix detector. Very clear separation between peaks.

Interestingly enough, the ADC in this GS-USB-PRO is able to over sample to 384Khz. Tested this last night and it ran flawlessly. I am still trying to figure out how it can do this while the literature suggests 48Khz is maximum sample rate.