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by mightyohm
Sat Feb 16, 2019 2:31 pm
Forum: Geiger Counter
Topic: Geiger Counter not working
Replies: 6
Views: 1143

Re: Geiger Counter not working

Glad you got it working! Let me know if there is anything else I can help you with.
by mightyohm
Sat Feb 16, 2019 12:18 pm
Forum: Geiger Counter
Topic: Geiger Counter not working
Replies: 6
Views: 1143

Re: Geiger Counter not working

First, confirm that the voltage from pin 3 to ground is still 2.9V, and the voltage from pin 2 to ground is 0V. This is the issue - if pin 3 is stuck high, then pin 2 should be high as well. Measure the voltage across R5, D2, C3, and R9. Those voltages will help us troubleshoot what is going on. It'...
by mightyohm
Tue Feb 12, 2019 9:28 pm
Forum: Geiger Counter
Topic: Geiger Counter not working
Replies: 6
Views: 1143

Re: Geiger Counter not working

Can you post a high res photo of the top and bottom of the PCB?

Check the direction of D2 and make sure it matches the silkscreen on the PCB. Also check the solder connections around R6, D2, C3, R9, and U1.
by mightyohm
Fri Jan 18, 2019 1:25 pm
Forum: Geiger Counter
Topic: Homemade GM tube
Replies: 7
Views: 4341

Re: Homemade GM tube

no change
by mightyohm
Thu Jan 10, 2019 10:45 pm
Forum: HV Rescue Shield
Topic: using re-set PIN on attiny85
Replies: 2
Views: 2080

Re: using re-set PIN on attiny85

Glad you got it working. Let me know if I can help with anything else!
by mightyohm
Sun Dec 16, 2018 4:14 pm
Forum: Geiger Counter
Topic: voltage problem Geiger Counter
Replies: 6
Views: 2942

Re: voltage problem Geiger Counter

There is an archived version of that page here: https://web.archive.org/web/20120626122 ... probe.html
by mightyohm
Sat Dec 15, 2018 11:03 am
Forum: Geiger Counter
Topic: voltage problem Geiger Counter
Replies: 6
Views: 2942

Re: voltage problem Geiger Counter

There's some information here:
viewtopic.php?f=15&t=487
by mightyohm
Tue Nov 06, 2018 10:32 am
Forum: Geiger Counter
Topic: SMD/ESP version
Replies: 6
Views: 2809

Re: SMD/ESP version

I suspect most switching NPNs would work fine for Q2. The 2n3904 is just a generic NPN.
by mightyohm
Mon Nov 05, 2018 10:00 pm
Forum: Geiger Counter
Topic: SMD/ESP version
Replies: 6
Views: 2809

Re: SMD/ESP version

The HV transistor needs to be a fast switching type because it is responsible for quickly switching current through L1 in order to generate a series of high voltage pulses that are filtered to create the HV supply. I'd try the STL128DN or a similar transistor - I can't guarantee that it will work bu...
by mightyohm
Sat Oct 06, 2018 3:10 pm
Forum: General Discussion
Topic: International shipping
Replies: 1
Views: 1390

Re: International shipping

Hello!

Shipping is added when you complete your purchase. As long as you enter a shipping address in Italy, international shipping should be automatically calculated.

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