Fusor Forums

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 -

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

I'm using cascode JFETs as well. (Tennelec 175 B does this)

I updated my post in the Richard Hester thread.

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 ...

Does anyone have this file?

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.

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...

Does anyone have a PDF of this manual (preferably with schematics)?

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...