GQ Electronics Technical Support Forum Active Users: / Visits Today:
Highest Active Users:
GQ Electronics Technical Support Forum
Home | Profile | Register | Active Topics | Members | Search | FAQ
Username:
 Password:
Save Password
Forgot your Password?

 All Forums
 GQ Electronics Forums
 2.GQ Geiger Muller Counter
 GMC-80 SCREAM		  New Topic  Reply to Topic
 Printer Friendly
Author Previous Topic Topic Next Topic  

ENIGMA6

USA
15 Posts
Posted - 09/23/2011 :  06:49:58  Show Profile  Reply with Quote
I am attempting to use a Russian SBT-9 [alpha/beta/gamma sensitive] tube but all the GMC-80 will do is scream. Is the default voltage too high for this tube? Any suggestions?
Reply #1

Odiez1

73 Posts
Posted - 09/23/2011 :  09:41:28  Show Profile  Reply with Quote
Do you mean by "default voltage" that it's turned all the way down?
Maybe there's some other factor involved..
You should try the mod from the "Probe Modifications" thread, adding the 104 (.1uF) capacitor to C2. That cleared up the "screaming effect" on my 080.
http://www.gqelectronicsllc.com/forum/topic.asp?TOPIC_ID=3403

Also, I found some specs on the SBT-9 and it looks like the 080 should work fine with it.
www.gstube.com/data/3004/
Good luck!
-Odie
Edited by - Odiez1 on 09/23/2011 10:39:40
Go to Top of Page
Reply #2

ENIGMA6

USA
15 Posts
Posted - 09/23/2011 :  15:30:25  Show Profile  Reply with Quote
Thanks for the information. I'll first try turning down the factory voltage [400v] setting to around 300v. If that doesn't fix it I'll try the capacitor mod. I appreciate the link to the specs data. Wasn't aware that page exhisted.
Go to Top of Page
Reply #3

ENIGMA6

USA
15 Posts
Posted - 09/23/2011 :  16:01:42  Show Profile  Reply with Quote
I turned down the voltage from the factory 405v to 290 which appears to be midange for this tube, seems to work ok now. No screaming except the continous clicking when I place an Americium 241 button in front of the alpha window. Thanks
Go to Top of Page
  Previous Topic Topic Next Topic  
 New Topic  Reply to Topic
 Printer Friendly
Jump To:
GQ Electronics Technical Support Forum © Copyright since 2011 Go To Top Of Page
Generated in 0.08 sec. Snitz's Forums 2000