[Boatanchors] [ Trivia questions

[Sheldon Daitch]

Bob,

I had to go back in the memory cells to
think about it.  In my high school years, I ran
35mm projectors in the home town theater,
Simplex heads, IIRC.

There was a shutter timing adjustment for travel ghosting.

I don't really recall the actual mechanical mechanism involved,
but involved the timing of the geneva movement and the
shutter mechanism.  It was an adjustment making sure
the timing geneva movement of the film path had stopped
the film motion across the aperture before opening the shutter
for the two bursts of light, and then the shutter was closed
before the film started moving again.

I had not thought about this in over 40 years.

see:

http://www.film-tech.com/warehouse/manuals/STRSIMPLEXHIST.pdf

or

http://www.film-tech.com/warehouse/pics/lyric/lyric.html

or

http://www.iceco.com/Strong/Simplex3570.pdf





73
Sheldon



Bob Hardie- W5UQ wrote:
> Yep Sheldon, you and Tom Norris got it right...  It has to do with 
> film projection.
>
> Travel Ghosts are seen when the film is moving in the frame when the 
> shutter is open.  The film needs to be perfectly still at that time or 
> the movement will be seen. The SMPTE test films we ran, allowed us to 
> see if the Travel Ghost was "leading or lagging", which would tell us 
> if the film was moving when the shutter opened up, or was moving just 
> as the shutter closed,  OR if the film was moving the whole time the 
> shutter was open.
>
> Revcom gave it a try too...  not too many tried to answer it.. Guess 
> it isn't something very many know about.
> I know this doesn't relate to ham radio... just thought it might be 
> fun to do...
> Okay...  does anyone know what an Iconoscope tube is?   How about 
> Image Orthicon?  I know many have heard of Vidicons and 
> Plumbicons....  All of these are TV camera tubes...
> Iconoscope tubes were one of the FIRST camera tubes used for TV (circa 
> 1947).  They were bulky, hard to use and required a LOT of light... 
> and had very low resolution.  I was a youngster, but I used them.  
> REMEMBER Howdy Doody or Kukla, Fran and Ollie ??
> Google them...  Here is a USPS site that made Stamps commemorating 
> some of the old TV shows:
> http://kukla.tv/ETM.html
>
> Okay BoatAnchors... I'm done........
> Bob   "the ole timy TV Broadcast Engineer"....    "A walk in the 
> PAST"  "Remembering when"......
>
> Sheldon Daitch wrote:
>> I know one use of the term, but it applies to a
>> motion picture film projector problem, which, of
>> course, could also relate to a TV problem.
>>
>> 73
>> Sheldon
>>
>> R
>>  
>>>> Okay,
>>>>          Who knows what a "travel ghost" is???   (or travel ghosts)
>>>>
>>>> If you know, don't publish it on here... just say I know...
>>>>
>>>> I'll publish the answer after guessing is over.
>>>>
>>>> Bet there aren't very many correct answers.
>>>>
>>>> Bob... PS it is a TV broadcasting question BUT it is also in other
>>>> fields too.
>>>>
>>>>           
>>> -------------------------------------------------------------------------------- 
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>>>   tml
>>>       
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