<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Thanks, Phillip. Excellent discourse.<div><br></div><div>One of my 1200s has a NEC TBC and does an excellent job fixing velocity errors. I will restore next a 1200B with the standard Ampex Amtec, Velcomp and Colortec.</div><div><br></div><div><div apple-content-edited="true"> <span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; -webkit-text-decorations-in-effect: none; text-indent: 0px; -webkit-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; -webkit-text-decorations-in-effect: none; text-indent: 0px; -webkit-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div><div>Best,</div><div>Park</div><div><br></div></div><div>C. Park Seward</div><div>Visit us: <a href="http://www.videopark.com">http://www.videopark.com</a></div><br class="Apple-interchange-newline"></span></div></span></div></span><br class="Apple-interchange-newline"> </div><br><div><div>On Jan 2, 2009, at 3:16 PM, Phillip G. Shaw wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><div bgcolor="#ffffff"><div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0pt; margin-left: 0in; ">Question: Why would the chroma not have the same error as the luminance?<br><br>How does velocity error show up in monochrome?</div><p class="MsoNormal" style="margin-top: 0in; margin-right: 0in; margin-bottom: 0pt; margin-left: 0in; "> </p><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0pt; margin-left: 0in; "><span style="font-size: 10pt; font-family: Arial; ">I would explain it this way. The Chrominance, when NTSC encoded, is ALL contained "of" the frequency of 3.58 Mhz, it is the Phase of the 3.58 that is modulated. The Color Burst on each line is the reference phase (Plant Sub carrier) used in decoding & error detection systems.</span></div><p class="MsoNormal" style="margin-top: 0in; margin-right: 0in; margin-bottom: 0pt; margin-left: 0in; "> </p><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0pt; margin-left: 0in; "><span style="font-size: 10pt; font-family: Arial; ">When you make a recording all Quad error exists to luminance & Chrominance equally and may be corrected together.</span></div><p class="MsoNormal" style="margin-top: 0in; margin-right: 0in; margin-bottom: 0pt; margin-left: 0in; "> </p><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0pt; margin-left: 0in; "><span style="font-size: 10pt; font-family: Arial; ">All error Correction systems "may” be correctly considered "Coarse" (Line rate Comparison) followed by "Fine" (3.58 Color Burst comparison). </span></div><p class="MsoNormal" style="margin-top: 0in; margin-right: 0in; margin-bottom: 0pt; margin-left: 0in; "><span style="font-size: 10pt; font-family: Arial; "></span> </p><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0pt; margin-left: 0in; "><span style="font-size: 10pt; font-family: Arial; ">The comparison of 3.58 color burst (off tape) to plant Sub carrier has a very narrow window. Phase between lines is 180 deg; phase between fields is 90 deg. The Phase of Color Burst is four (4) fields or 2 frames. The 140nsec shift most editors have/had to deal with is difference between</span> <span style="font-size: 10pt; font-family: Arial; ">frame 1 or 2. RS170A defines field one of the four field sequence but... but... As my old friend Charlie Spicer would say in his SMPTE papers.. "Nobody can tell if it 12 PM or 12 AM” just by looking at the NTSC Color Burst</span></div><p class="MsoNormal" style="margin-top: 0in; margin-right: 0in; margin-bottom: 0pt; margin-left: 0in; "> </p><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0pt; margin-left: 0in; "><span style="font-size: 10pt; font-family: Arial; ">Back to the non -phase problem: When you encode chrominance using plant sub carrier you are basically burning-In all error of chrominance. All Quad error exists but you can't see it with your eye or corrected it electronically.</span></div><p class="MsoNormal" style="margin-top: 0in; margin-right: 0in; margin-bottom: 0pt; margin-left: 0in; "> </p><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0pt; margin-left: 0in; "><span style="font-size: 10pt; font-family: Arial; ">The functional block of a NTSC decoder was not trivial in the</span><span class="Apple-converted-space"> </span><span style="font-size: 10pt; font-family: Arial; ">Era of quads, remember the one line delay using Glass in the drop out comp. The Non-Standard button must bypass the line-to-line TBC correction but may have allowed burst 3.58 correction;</span> <span style="font-size: 10pt; font-family: Arial; ">again that correction is limited unless line correction is done first.</span></div><p class="MsoNormal" style="margin-top: 0in; margin-right: 0in; margin-bottom: 0pt; margin-left: 0in; "> </p><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0pt; margin-left: 0in; "><span style="font-size: 10pt; font-family: Arial; ">The First demod/re-mod solution to non-phase error was provided by after market TBC’s for Umatic, in about</span><span class="Apple-converted-space"> </span><span style="font-size: 10pt; font-family: Arial; ">1978-79. Those gave way to hi-end GRB decoding with color-correction</span> <span style="font-size: 10pt; font-family: Arial; ">& all the feature sets, these can be used</span><span class="Apple-converted-space"> </span><span style="font-size: 10pt; font-family: Arial; ">on all NTSC encoded signals.</span></div><p class="MsoNormal" style="margin-top: 0in; margin-right: 0in; margin-bottom: 0pt; margin-left: 0in; "><br></p></div></div></span></blockquote></div></div></body></html>