[R-390] meters arrived

[Mahlon Haunschild]

Don,

All of the R-390A meters I've handled most definitely are original.  As 
I said earlier, an ordinary G-M counter doesn't count the alpha 
particles from the radium decay, but does count the beta particles and 
gamma rays from the decay products (polonium, lead, and bismuth).

You could of course count the alpha particles from the radium decay if 
you had a counter with a suitable G-M tube (mica window) and removed the 
dial from the meter, but that's an academic exercise.

regards,

Mahlon - K4OQ

> ------------------------------------------------------------------------
> 
> Subject:
> Re: [R-390] meters arrived
> From:
> 2002tii <bmw2002tii at nerdshack.com>
> Date:
> Sun, 13 Sep 2009 22:48:23 -0400
> To:
> r-390 at mailman.qth.net
> 
> To:
> r-390 at mailman.qth.net
> 
> 
> Mahlon wrote:
> 
>> The ones in my '68 EAC are not radioactive.  Meter brand is unknown.
> 
> It's not always easy to tell, but do they appear to be the original 
> meters or replacements?
> 
> Don