In article ,
"Michael A. Terrell" wrote:

" wrote:

I put myself thru college in 1953-57 doing Admiral tv repair in Fort
Pierce, Florida. There was tremendous variability in how sets came from
the factory. There was also tremendous variability in what various
consumers wanted as the color of "white". We aimed to keep our customers
happy and would set "white" to whatever was their preference.

The nearest tv station was in West Palm Beach 50 miles to the south, all
others were in Miami, 120 miles to the south. Atmospheric conditions
determined the quality of the signals received at those distances. The
yagi antennas used had back lobes that would also pick up Jacksonville 200
miles to the north, on the same channels as Miami, under certain
atmospheric conditions. The resulting signals gave strange effects.

The white block in the upper left-hand corner of the picture signalling a
switch to a commercial was a holdover from motion pictures. When the reel
of film was almost over, like about 10 seconds from the end, the white
block was a signal to the projectionist to switch to the alternate
projector which picked up the "story line" at exactly the end of the film
in the first projector. Since early tv used a lot of film-based
programming, the white block made the transition to tv in that manner.


The 'Cue mark' was the upper right, and in a series of three. They
were made by either scraping away the emulsion, or punching a pinhole
for several frames for each cue mark.

The first to alert the operator. The second was to start the other
projector, and the third to switch the semaphores to switch the optical
path from one projector to the other. I ran a pair of RCA TP66, 16 mm
film projectors at an AFRTS TV station, for a year, back in the '70s.

I got myself through college in the early sixties by working in a local
TV station's engineering department. Back then, there was no other way
to distribute movies for things like the local "late movie" than as 16mm
film on large reels. The movies were always provided as packages of a
couple dozen (generally one or two decent ones and the rest dogs). The
cans of film worked their way around, one movie at the time, through a
series of local stations -- you got them from KXXX-TV and sent them on
to KYYY-TV, who then sent them on, etc. Assuming the station(s) upstream
of you were responsible, you got a "new" movie every week.

By the time the film rolls had been around that circuit once or twice,
nearly every frame in the whole film had been punctured with a cue mark
(because every station had their own idea of where the commercials
should be inserted).

All the holes were, of course, bright white, which messed with the
automatic video gain circuitry of the projectors.

Isaac