Search found 135 matches

by Joe Gayo
Tue Oct 20, 2020 6:44 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Not Quite As Simple CSA
Replies: 63
Views: 20645

Re: Not Quite As Simple CSA

Thanks.

I just acquired qty. 300 of original PN4416A parts. I'll be measuring and matching for the cascode stage.

Here is the final board -
CSA-02.jpg
by Joe Gayo
Tue Oct 20, 2020 12:52 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Not Quite As Simple CSA
Replies: 63
Views: 20645

Re: Not Quite As Simple CSA

I'll sell the bare boards for $10 each and tested assemblies for $50 (without pulser) and $75 (with pulser).

Bare boards without the pulser circuit are $5 each
by Joe Gayo
Tue Oct 20, 2020 12:41 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: My preamp design
Replies: 1
Views: 220

Re: My preamp design

I'm using cascode JFETs as well. (Tennelec 175 B does this)
by Joe Gayo
Mon Oct 19, 2020 9:35 pm
Forum: FAQs: Neutron - Radiation Detection
Topic: FAQ - Roll your own preamp (Richard Hester design)
Replies: 13
Views: 649

Re: FAQ - Roll your own preamp (Richard Hester design)

I updated my post in the Richard Hester thread.
by Joe Gayo
Mon Oct 19, 2020 9:20 pm
Forum: FAQs: Neutron - Radiation Detection
Topic: FAQ - Roll your own preamp (Richard Hester design)
Replies: 13
Views: 649

Re: FAQ - Roll your own preamp (Richard Hester design)

Some thoughts: Before making my iteration I looked through all of Richard Hester's designs and made changes - - I think the anode connection of D6 is less than optimal since the feedback bandwidth is already pretty low and the performance degrades at higher count rates (I increased the bandwidth in ...
by Joe Gayo
Mon Oct 19, 2020 5:45 pm
Forum: Files
Topic: Photodiode Pulser Circuit
Replies: 3
Views: 5048

Re: Photodiode Pulser Circuit

Does anyone have this file?
by Joe Gayo
Mon Oct 19, 2020 5:24 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Not Quite As Simple CSA
Replies: 63
Views: 20645

Re: Not Quite As Simple CSA

Cascode JFET input
Moved the feedback cap after the input cap
2nd Order RC Bias Filter
Photodiode Pulser w/ adjustable current source (driven by an external microcontroller or signal generator)
9V Battery Holder

I recommend 1p and 47 Meg feedback.
2Layer.PDF
(578.64 KiB) Downloaded 25 times
by Joe Gayo
Mon Oct 19, 2020 5:23 am
Forum: FAQs: Neutron - Radiation Detection
Topic: FAQ - Roll your own preamp (Richard Hester design)
Replies: 13
Views: 649

Re: FAQ - Roll your own preamp (Richard Hester design)

I converted Richard Hester's design to a PCB with a few modifications (the main one being a high voltage bias connection with a 2nd order RC filter). I'm building a number of these boards late next week. I'm willing to sell completed and tested boards or just the bare boards. Is anyone interested? I...
by Joe Gayo
Wed Oct 07, 2020 3:26 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Ortec 487 Manual
Replies: 0
Views: 317

Ortec 487 Manual

Does anyone have a PDF of this manual (preferably with schematics)?
by Joe Gayo
Tue Sep 15, 2020 12:00 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Uranium Ore Gamma Spec
Replies: 2
Views: 718

Uranium Ore Gamma Spec

I've been working on refining my gamma spectroscopy set up and took the following measurement with the following items: Bicron 2x2 NaI Detector @ 900V Ortec 113 PreAmp (1000p) Canberra 3202 HV Power Supply Canberra 2020 Spec Amp (x100, 4usec Shaping time, w/ PUR on) Canberra 35+ (1000 sec count) Ore...