TV buzzes with overly white video
On Jan 22, 6:48*pm, "Michael A. Terrell"
wrote:
wrote:
A pad shouldn't help as the 'automatic gain control' will just push up
the gain to make up for the pad. If it's in an extremely high RF
condition, the pad might help but it's rare to get that much signal.
GG
* *Have you ever tried a pad? *The AGC system in a TV is a very
basic
system that is designed to keep the level within a range, and
driving it
to the upper limit can cause sync buzz. *I have seen complex AGC
systems
with 14 op amps, and the DC offset was limited to 1.5 mV over the
entire
range. *It could maintain the output level to less than a .1 dB
change
over the entire useful RF input range. *You WILL NOT see a AGC
system
like this in a consumer level receiver.
--
Service to my country? Been there, Done that, and I've got my DD214
to
prove it.
Member of DAV #85.
Michael A. Terrell
Central Florida
Yeah I've tried pads and they do make a difference if the signal is so
strong as to overload the front end but as I said earlier, that
condition is not very common. More common for the AGC to be pushing
the visual carrier to cutoff causing the buzz.
GG
|