Search found 13 matches

by wbp
Fri Nov 18, 2011 6:58 pm
Forum: Geiger Counter
Topic: How to you measure the voltage
Replies: 15
Views: 27629

Re: How to you measure the voltage

I adjusted the pot for 400V (measured 4.00 V with the 1G resistor using a Fluke 289, 10M input). When I measure TP2 directly, I get 185 volts. This might be useful for those who have a similar meter but no 1G resistor.

William
by wbp
Fri Nov 18, 2011 5:19 pm
Forum: Geiger Counter
Topic: How to you measure the voltage
Replies: 15
Views: 27629

Re: How to you measure the voltage

Changed R8 from 15 to 22 ohms. Now I can have the correct voltage range - 300 to 600.

William
by wbp
Thu Nov 17, 2011 7:08 pm
Forum: Geiger Counter
Topic: How to you measure the voltage
Replies: 15
Views: 27629

Re: How to you measure the voltage

I purchased the suggested 1G resistor from Mouser. I've swapped R5 & R6 per another thread. Using a Fluke 117 (10M input) The LOWEST value I can get at TP2 is 5.00 Vdc, with the pot all the way to the left. With the pot all the way up I measure around 9.5 Vdc. Seems like something isn't working ...