[TowerTalk] Fwd: Fwd: Now THIS is a tower climb!

[Jim Thomson]

Date: Wed, 14 Jan 2015 14:05:16 -0500
From: Hans Hammarquist via TowerTalk <towertalk at contesting.com>
To: towertalk at contesting.com
Subject: [TowerTalk] Fwd:  Fwd:  Now THIS is a tower climb!

It's a well know fact that the life span of incandescent light  bulbs increases with lower operating voltage. If I remember it right the lifespan increases by 7 times with a 10% decrease in voltage. I guess a 240V bulb working on 120V would outlast the life of the radio station. Light efficiency (power in - light out) is not that good though.


Hans - N2JFS

##  I installed 130 vac rated flood lamps for my motion detector lights outdoors.  5 pairs of them, 10 in total.   They are 100 w rated.  When run on 120 vac, they are not as bright, abt the same as a 75 w bulb. 
I installed them back in 1998.  They go on and off all night long if windy outside.  They are just starting to burn out now, 2 of em.... 17 years later.  If a thermistor was used, they would never burn out. 
They still don’t make a LED replacement for outdoor floodlamps...yet.   The indoor leds are supposed to be good for 25k hrs. 

##  on a tower light setup, if 130 v rated bulbs used..and run on 120 vac.... and thermistor used to ramp the V up.... or a variac, they would never burn out.   Or use 120 vac rated bulbs..and use a variac to slowly
bring em up to 100-110 volts.  Tower’s need redundant bulbs..or redundant leds. 

##  they already make heavy duty, long lasting bulbs  for hard to reach places, been around for 35 yrs or more.  They contain a real heavy duty filament.  Since the cold resistance is  one tenth the hot resistance, the bulbs  always burn out upon turn on.   A variac, or simple dimmer, or thermistor would solve that problem..plus lower the V 10%. 

Jim   VE7RF