[Boatanchors] LINE VOLTAGE, FILAMENT VOLTAGE and SANITY

[Jim Wilhite]

Commercial service that broadcasts either 18 or 24 hours per day, seven days 
per week is considered CCS.  Amateur service is ICAS.  There is a world of 
difference.  The Collins 30S1 is the only amplifier I ever saw with a 
metering position for the tube filament and an easy way to adjust it.  But 
then again, they targeted the military and government service, only hams 
with a lot of money could afford them.

In CCS tube longevity translates to service life which translates into 
dollars.  When restoring a piece of 60 years old tube equipment, you will 
replace far more electrolytic capacitors than tubes.  If anyone looks at our 
obsession with exact voltages, you will note it came with the rise of 
digital voltmeters.  Sort of like the SSB stations that operate on exact 
frequencies because of digital frequency readouts.

Jim
W5JO


-----Original Message----- 


It is well know in the broadcast industry that excessive heater voltage
_greatly __reduces_ tube life.  This is most acute in transmitting tubes
because of their cost, but also applies to receiving tubes.