GEC MODEL 2028
There are a couple of faults on this dual -standard hybrid
colour receiver. First some buzzing on subtitles. Secondly
there’s intermittent brightness. A new PL802 luminance
output valve has been fitted.
To reduce the sound buzz, try a very small adjustment to
L122 in the sound discriminator can T110 and check the
setting of the a.m. rejector P102. If this is not successful, it
may be necessary to follow the alignment procedure given
in the manual. Intermittent brightness may be due to a noisy
beam current limiter preset P507 or brightness control P4.
Also check plug PL5 on the timebase board for poor contacts
or a dry -joint, that the c.r.t.’s first anode voltages are
steady (check the feed components R529 and C527 if
necessary), and for dry -joints in any of these areas.