[QuadList] Helicals, Quads

[Dennis Degan]

		On Feb 11, 2010, at 9:41 AM, <bill.spencer at northstarstudios.tv> wrote:

 > Thanks Dennis for the much more elegant explanation.  I knew I was 
upside down when I sent the post, but figured since analog tv is gone 
it wouldn't matter any more! (See how quick I forgot!)

		I sigh:

	You're right; it doesn't matter any more.  But that's all I got: a 
head full of useless old information.  All I can do now is use it to 
win bar bets: "Hey, did you know that we used to transmit video upside 
down?  I can prove it!"

		Bill also said:

 > Also, chroma can be over peak white and yellow is the worst offender, 
so whenever the FCC wanted to gig a public station they only had to 
check
the listings to see when Sesame Street was on and the first appearance 
of Big Bird would buzz like crazy.

		I add:

	Yes, we tried to limit the yellow bird as best as we could.  It wasn't 
easy.

		Bill:

 > Grass came out with a mod for the old 900 series proc amp that would 
clip that stuff so the transmitter didn't buzz, but the recordings were 
quite often overdeviated on the high chroma.  And it was the chroma 
comp circuits in the RCA TK-44 that allowed that boost to be there.

		I say:

	It's been 28 years since I worked on that show.  I thought the 
ChromaComp board allowed control of the color and helped to PREVENT 
oversaturation of the yellow, NOT to allow the boost to be there.  We'd 
use the video scope to see if the modulated yellow of the bird was 
going too high and to correct it, we'd cut back the yellow saturation a 
bit.  We didn't want to iris down the whole scene so we'd limit the 
yellow saturation instead.  It seemed to be a satisfactory compromise.
	I vaguely remember the GV 900 procamp.  I think it had both a hard 
clip that simply chopped off the top, and a 'soft' clip that rounded 
the chroma peaks.  The hard clip could cause as many problems as it 
solved but the 'soft' clip (which is what I think you are referring to, 
Bill) worked wonders.

		Bill also remembered:

 > I miss Teacher's Deli across from the 81st St. studio!

		I say:

	 I used to eat lunch at Teacher's pretty often when I worked on the 
show.  I just checked Google Maps and it looks like there's a 
McDonald's there now; how sad.  Zabar's was across Broadway from the 
studio and is still there.
	There was another restaurant I used to frequent between 81st and 82nd 
that had the greatest salads.  It was called "The Front Porch", I 
think.  Finally, there was the "Burger Joint" also across Broadway, at 
77th as I recall.  I loved that place.  It was worth the short walk.
	Here's what the building looked like as of 2004, since the studio had 
been replaced with a high-rise condo apartment building:
				<http://www.flickr.com/photos/dennisdegan/557875987/>
	And to keep this on topic, here's what the quad tape room looked like 
in 1979:
				<http://www.flickr.com/photos/dennisdegan/557632228/>
	and the edit room next door:
				<http://www.flickr.com/photos/dennisdegan/557631348/>
	There are other photos from Reeves/Teletape's 81st Street Studio in 
this picture set as well.

			Dennis Degan, Video Editor-Consultant-Knowledge Bank
	  					NBC Today Show, New York