22-10-2016, 07:35 PM
(22-10-2016, 12:56 PM)ppppenguin Wrote: The original need was for a full screen (or at least a lot of peak white) peak white so that RF level measurements could be made sensibly on System A. You need a decent area of 100% carrier for a test set to work.
I think I should clarify this: both the Signal Level Measurement unit I use (Calan) and the simpler one (Swires) I donated to the museum, scan the band(s) of interest. Thus it is important that a sufficient period of maximum carrier is present whilst the channel is being scanned. No problem with negative modulation as the sync peaks are at 100% modulation but a serious problem with the positive modulation of 405-line signals when peak carrier becomes a random event of indeterminate duration!
