From: spam@spam.com   
      
   On Wed, 20 Jul 2011 12:31:17 -0400, "Arny Krueger"    
   wrote:   
      
   >   
   >"flipper"  wrote in message   
   >news:8reb27t53ivpcuo68v8it5mgelu93b1kb3@4ax.com...   
   >> On Tue, 19 Jul 2011 11:40:47 -0400, "Arny Krueger"    
   >> wrote:   
   >>   
   >>>   
   >>>"Patrick Turner"  wrote in message   
   >>>news:d791dbd6-cefd-490c-bba0-96e5aa6985ee@j9g2000prj.googlegroups.com...   
   >>>>I searched in Google for the existance of a schematic for a phase   
   >>>> locked loop using vaccum tubes, and hundreds of images came up but NOT   
   >>>> ONE with a phase locked loop that could be used for better AM   
   >>>> detection.   
   >>>>   
   >>>> I must away to my shed to do some work rather than chase fancy fairy   
   >>>> circuits on the Internet.   
   >>>>   
   >>>   
   >>>If they'd ever declassify some of the radar sets I worked on in the late   
   >>>1960s... 400+ tubes each, and a number of PLL-stabilized thises and thats.   
   >>>   
   >>   
   >> Every vacuum tube 'electronic' (meaning CRT vs mechanical) television   
   >> receiver had at least one: the horizontal oscillator/sync.   
   >   
   >> In color sets you also have the chroma osc.   
   >   
   >   
   >   
   >Yes, those had to be in phase with the transmitter's clocks. I remember some   
   >phase detectors in the old NTSC sets - an instant tip-off that there was   
   >some kind of phase locked oscillator in play.   
   >   
      
   This is where PAL really won out over NTSC. Each alternate line the   
   chroma phase leads or lags by 45 degrees, and the PLL locks to the   
   average - which is true phase. The result is that when there is an   
   overall phase error in the chroma signal, alternate lines lead and lag   
   the proper phase. Add them together and the error vanishes. With NTSC   
   a phase error means a wrong colour.   
      
   d   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)