[Milsurplus] TBY-8 batteries

[WA5CAB at cs.com]

(Roger, I hope later this week to get you an answer on the DM-33.)

The TBY had three power supplies made for it, all exactly the same size.  
NT-19018 dry battery.  NT-20144 wet cell vibrator supply.  NT-20206 115 VAC/VDC 
vibrator supply.  The battery used with the 20144 is NT-19029.  19029 is a 
lead-acid battery rated 4.2 volts 40 AH.  I don't think anyone still makes 4.2 
volt gel-cells but several do make 2.1 volt cells.  If you hook a 6.3 volt 
battery up to the 20144 neither it nor the radio will last very long.  You'll (for a 
short time) be putting a nominal 234 VDC on the radio.  Rated is 156.  And 
the vibrator of course has a 4 volt coil and won't like running at 150% of 
rated.

On the radiation subject, for the bulk of the 30 years that I had a "day job" 
as Chief Engineer/Engineering Manager (civilian) and Ordnance Officer 
(military) my main collateral duty was Radiation Safety Officer.  I have no feel for 
the actual magnitude of the figures previously quoted in this thread as they 
are in French units, but I'm sure they are correct as far as they go.  But I 
will point out that there is far more to the biological effects of ionizing 
radiation than what you read on a survey meter.  And that reporting that holding 
the survey meter probe against a TBY pegged the meter is hardly informative.  
Such meters have range switches.  And if the highest range will not bring the 
meter off the peg, you need to procure a higher range instrument.  Further, 
biological effects cannot be linearly extrapolated from the readings of a survey 
meter.  Biological effects depend to a large extent on the penetrating ability 
of the ray or particle.  The reason that low range survey instruments have 
Alpha windows over the detector probe is that Alpha particles (Helium nuclei) 
generally have far less penetrating power than gamma rays.

Finally, the primary health hazard to humans from radium based paints is from 
potential ingestion of the solid material.  The actual radiation level a few 
inches in front of a TBY is less than the background in certain parts of 
France and India.  And is primarily Alpha, not Gamma as in those cases.

So don't routinely lick your TBY and stay out of certain areas of France and 
India.  And all you will have to worry about are thunderstorms, hurricanes, 
earthquakes, large meteor strikes, Muslim dirty nukes and suicide bombers, 
muggers and traffic accidents.

Robert Downs - Houston
<http://www.wa5cab.com> (Web Store)
MVPA 9480
<wa5cab at cs.com> (Primary email)
<wa5cab at houston.rr.com> (Backup email)
   
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