HBO broadcasts this special color bar test pattern, needed for calibration, once a month per station, at 5:30 AM ET, calling it a "Transmission Test". Here is their current schedule:
http://www.hbo.com/search?type=schedu...
I'm showing how this can substitute for a gray scale ramp pattern, the one that ideally should be used to adjust the Panasonic to the incoming source signal. This works because this particular color bar pattern, from HBO, actually has a hidden grey scale ramp from white on the left to black on the right if one removes all the color placed over it, which is how TV images are formed. BUT NOT ALL COLOR BAR PATTERNS HAVE THIS. If you don't see pure white on the left edge and pure black on the right then you have the WRONG pattern to use. To the best of my knowledge there is no need to reduce the color when performing this test since they don't contaminate the readings the waveform monitor measures.