Wooo digging up an old thread!

Anyway - I've always wondered - how does the PAL decoder know which way the phase is, to decode properly?

"Oscillating burst"

A (R-Y) or -(R-Y) component is added to the burst on alternate lines, making its phase plus or minus 45 degrees from the NTSC burst.

As mentioned somewhere here, there was a patent on detecting this in the receiver, but one maker avoided the patent by not using the detector. Instead, they added a button so the user could flip the phase sequence from plus/minus to minus/plus in case it came up wrong at random.

VIR= Vertical Interval Reference. Remember, TV stations using video had to stay synchronized to the network color burst reference for timing and interchange purposes. Also remember there was Time Code involved for locally produced video content using video tape sources. Known as SMPTE (Society Of Motion Picture and Television Engineers) Time Code. Hope this explains the underlying issues with VIR's use and implementation and allow set owners freedom of their vision and taste in color settings at home.

The thread that refuses to die!

Kent's comment just made something click for me: on our GE VIR set, everything always went whacky when the local ABC affiliate switched from network content to local, either programming or commercial breaks: tint so far off you couldn't manually adjust it so bad. It was common to see bright blue faces for a few seconds when they switched. It must have been a sync error at the station.