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Lights



rmarkham@VNET.IBM.COM wrote:

>- 6 ounces of batteries?!?!  I'm assuming those
>are for your headlamp?  Do you realize that between
>your headlamp and the spare batteries, you're carrying
>1 lb 6 ounces just for a light at night.  Most of the time
>when it gets dark, I'm too exhausted to read or write for
>very long.  Couldn't you just carry one of those maglites
>that you can buy the headband holder for?  You would
>save at least a pound even if you did bring spare batteries.
>Also, the candle lantern seems like overkill too.  Why not
>just bring the candle as an emergency heat source and forget
>the rest.  I've always found that the candle lantern was
>nearly impossible to read by....

Oil-burning inserts for candle lanterns are considerably brighter than
candles but they WILL leak in backpacking application.  Beeswax candles are
nice because the melting point of beeswax is 140F and they don't go "glurp"
in summer, even in a car.  Beeswax has other applications, e.g.
field-expedient boot seam-sealer.  I buy beeswax candles from beekeepers
at the local farmers' market.

The MiniMag (tm) is the most reliable flashlight I've ever used, probably
because the internal contacts are silver plated.  The switch mechanism of
my first one wore out after about 8 years of almost-daily use.

The MiniMag bulb lasts about two sets of batteries.  Don't neglect to
replenish the spare bulb in the flashlight base!  A sometimes-undesirable
nuance of the MiniMag is that you need two hands to operate the switch.

I hate to say this because the U.S. Petzl distributors are friends, but I
consider the Petzl Micro headlamp too unreliable for serious use:  The
internal contacts are failure-prone, and the elastic in the headband wears
out almost immediately.

The Princeton Tec Solo (tm) headlamp (made in USA, available from Campmor
for about $1.50 more than the Petzl Micro) is far more robust and cost-
effective. (The fleece stuff-sack alone is worth the extra $1.50).  It is
fully weatherproof, and all contacts are easily accessible for cleaning
with a pencil eraser (don't use sandpaper, which removes the metal
plating).  It uses two AA-cells, comes with two bulbs (halogen, very
bright, and krypton, lower current).  The bulbs have flanged bases like
common flashlght bulbs (PR-2 et al).  It does not have variable focus, but
has interchangeable reflectors, one which diffuses the beam somewhat.

The krypton bulb is electrically equivalent to type PR-6 (300 mA) but is
considerably brighter.  Princeton says it's good for 8 hours of continuous
light:  Capacity of alkaline AA-cells is roughly 2250 mA-hours (varies with
load current, duty cycle, temperature, manufacturer).

I don't know the life rating of the bulbs.  Life rating of PR-6 is 30 hours
(extremely long for a flashlight bulb).  Krypton-filled bulbs are more
efficient than vacuum or argon-filled bulbs (and they prevent Superman from
giving you any trouble! B-)

I intend to experiment with replacing the rubber forehead-pad with loop-
type Velcro, which should be less sweaty, and usable for mounting the lamp
in various places.

Bulb currents:

halogen (HPR-52)         500 mA
krypton (PR-6 equiv.)    300 mA
MiniMag                  290 mA
Petzl Micro              250 mA (screw-base bulb, won't fit Princeton.)

First aid for ratty flashlights:  Clean the contacts with a pencil eraser
as above.  Rub ends of batteries on a rough surface (newsprint paper,
backside of leather belt, etc.).  Inspect the tip of the bulb base:  It is
made of soft solder which tends to oxidize and become flattened by contact
pressure.  Polish the tip similarly to the batteries, or use a soldering
iron and solder to restore its original round, bright appearance.

--  Frank     reid@indiana.edu

"Things like that only happen in comic books; this is real life!"
         -- Batman

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