Electrohome ECP Series
Located below each CRT are the H deflection/convergence output board. Again, all
three boards are identical, and you can swap these boards between tubes. Note
however that a failure on one of these tubes usually shuts down the HV, and the
H error light will light up on the back. Swapping the boards within the set will
do nothing, you’d need to get a working deflection board and swap out these
boards one at a time.
Horizontal Deflection board
The above picture shows the two main adjustments on the H deflection board.
The master width pot works ONLY on the green board, the R and B width pots have
no effect. This is normal. Set the width on the keypad to ‘5’, and set this
width pot so that a good amount of phosphor area is used. That allows some give
and take adjustments via the width control on the keypad when changing
resolutions.
The V size control works independently for each color. The idea of these
controls is to match the height of all three CRT’s without making massive use of
convergence controls to shift the height of each color. This reduces convergence
drift.
The convergence and H/V yoke plugs connect at the back edge of each
deflection board. The H and V connectors pull out and reverse 180 degrees. This
orients the image correctly whether floor or ceiling mounting. Both connectors
need to be flipped on each H deflection board to properly orient the scanning of
each tube.
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