[Milsurplus] Wireless Set No.19 MK II Panel Markings

[Gary Pewitt]

I hope someone better informed will correct me if I am wrong but I 
believe there were two basic ways to achieve a luminous dial.  One 
involved a radioactive substance giving off high energy radiation 
such as gamma rays ( alpha and beta particles won't get the job done) 
which stimulated a phosphor into giving off visible light.  The other 
way was to use a phosphor that stored energy from sunlight and slowly 
gave it back, visible, of course, only in the dark.  The problem with 
this method was that the glow didn't last long enough ie. a few 
minutes to a few hours.  I don't believe that they used Tritium as 
far back as WWII or even the Korean war.  You can get Mil surplus 
compasses with Tritium on the face and needle as well as Tritium gun 
sights nowadays.  Unfortunately Tritium has a -much- shorter half 
life than Radium and the glow fades over the years.  If I remember 
the half life of Tritium is about 20 years while Radium is more like 50,000.
Like I said, corrections welcome.
73  Gary



At 11:50 AM 1/19/2009, Peter and Edie Hamersma wrote:
>Hello Everyone,
>
>I have a question on the panel markings on the Wireless Set No.19 MK 
>II. I recently dug mine out of storage and noticed the panel 
>markings glow very nicely in the dark after being exposed to light. 
>The marking don't have that usual yellowish-brown flakey look of 
>radium paint but, the Canadian Wireless Set 19 website alludes to it 
>being radioactive under an article on radiation hazards in old 
>military radios. An old "IN Uniform" column by Walt, KJ4KV, on the 
>19 set states that while the panel is luminescent it is not 
>radioactive. Can anyone tell me what I'm dealing with before I 
>attempt to clean the front panel which it badly needs. Better safe than sorry.
>
>Thanks and 73,
>Pete, WB2JWU
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Gary Pewitt  N9ZSV   garypewitt at centurytel.net  479 675 4376
1500 French Prairie Rd. Booneville, Arkansas  72927
Sturgeon's Law "Ninety percent of everything is crap."
Pewitt's Law: But it's that other 10% that makes life worth living."