20-07-2017, 01:39 AM
At this site: http://www.maximus-randd.com/piets-home-...n-pt2.html, around 80% down the page, there is a description of Philips’ first multistandard TV receiver for Belgium, the 17TX100. From that:
“The video IF was a regular staggered tuning chain, with the modification that for norm F the lower frequency was decreased further, as well as the sound trap at the input. This switched the video passband between 5 and roughly 6,5MHz, so clearly not the full 10,5MHz official video bandwidth of the French standard. This will have given decreased horizontal resolution for this norm, which was probably deemed acceptable.”
I think that that really referred to norm E, not norm F, but it indicates that some effort was made to obtain better than 5 MHz vision bandwidth for norm E.
Cheers,
Steve
“The video IF was a regular staggered tuning chain, with the modification that for norm F the lower frequency was decreased further, as well as the sound trap at the input. This switched the video passband between 5 and roughly 6,5MHz, so clearly not the full 10,5MHz official video bandwidth of the French standard. This will have given decreased horizontal resolution for this norm, which was probably deemed acceptable.”
I think that that really referred to norm E, not norm F, but it indicates that some effort was made to obtain better than 5 MHz vision bandwidth for norm E.
Cheers,
Steve
