"No bulbs exactly match the sensitivity of the paper, but the commonly
available ultraviolet, 'type BL' bulbs, come very close to the ideal. Also
excellent are graphic arts bulbs which have less UV and more blue light than
type BL.
"Type BL bulbs are commonly available in 18", 24" and 48" lengths. The 18"
bulb comes in 15 watt and 25 watt vesions. The 24" is available only in 20
watts, and the 48" size only in 40 watts. The 18" 25 watt version is the
fastest. Sylvania calls its equivalent bulbs '350' as in F350/15T8. We
stock 24" 40 watt AQA graphic arts type bulbs that we install in our high
speed 16"x20" exposure units. This bulb is twice as fast as the 24" 20 watt
type BL bulb. Normal bulb life for all types is over 2000 hours. Over
time, they will gradually lose brightness. We re-lamp our in-house units
every two years since they get heavy use. With sporadic use, you can go much
longer.
"Ballasts: Ballasts have to be matched to both the wattage and the length of
the bulb. Each ballast will power two bulbs. The appropriate pairings are
given in the chart (below). You can choose either a normal or a higher
output (HO) ballast for our 40 watt AQA bulb. You'll give up some bulb life
in exchange for a faster printing spped with the HO ballast."
Bulbs (1 ballast for every 2 bulbs): Ballasts:
================================================================
GE 15 watt 18" F15T8/BL or equivalent Valmont 8G3912F
or equivalent (Sylvania's is or equivalent
F350/15T8)
----------------------------------------------------------------
GE 25 watt 18" F25T8/BL Valmont 8G4126WF
or equivalent or equivalent
----------------------------------------------------------------
GE 20 watt 24" F20T12/BL Advance RL25P20
or equivalent or equivalent
----------------------------------------------------------------
Voltarc 40 watt 24" Valmont 8G1024, or
F40T12/AQA/BP-40 W Valmont HO8G3885 W
or equivalent (higher speed)
----------------------------------------------------------------
GE 40 watt 48" F40T12/BL Valmont 8G1024
or equivalent or equivalent
================================================================
Regarding the recent questions about negative duplication and enlargement:
The Palladio manual also has a good discussion of these techniques.
Palladio's address: PO Box 28, Cambridge MA 02140; Phone 617-547-8703.
Charllie Palmer
Albuquerque NM USA