Friday 6 December 2019

Annoyed - wrong TIG rod!

The long awaited package from eBay seller "mitools" arrived today - and it's the WRONG item!

It should of course be a 2% thoriated rod, colour coded red, and 1.2mm thick. What they have sent is a 2% CERIATED 2.1mm rod, colour coded grey. This is useless as a check source for the blindingly obvious reason of it not being radioactive!

So it's going back for exchange  and perhaps sometime soon I might finally have a check source!

I've ordered some MPSA18 transistors as well to try the base control method of regulating the HV circuit.  These have very high gain. 

The circuit diagram of my current Geiger counter is shown below. I also need to add an external pulse output to drive a counter or meter.

Simple Geiger 'clicker'

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