On Sun, 23 Sep 2007 16:41:17 -0700, Joerg <notthisjoergsch@removethispacbell.net> wrote:>And then the moment of truth cometh. I am a bit concerned that the >chosen system could waffle under really strong multipath conditions like >where we live.Digital transmission do NOT suffer, in ANY WAY, SHAPE, OR FORM, from multipath distortions!
Re: Why is video inverted for transmission?
Started by ●September 23, 2007
Reply by ●September 23, 20072007-09-23
On Sun, 23 Sep 2007 16:41:17 -0700, Joerg <notthisjoergsch@removethispacbell.net> wrote:>And then the moment of truth cometh. I am a bit concerned that the >chosen system could waffle under really strong multipath conditions like >where we live.Digital transmission do NOT suffer, in ANY WAY, SHAPE, OR FORM, from multipath distortions!
Reply by ●October 12, 20072007-10-12
On Wed, 10 Oct 2007 11:05:46 -0800, glen herrmannsfeldt <gah@ugcs.caltech.edu> wrote:>Gary Tait wrote: >(snip) > >> It depends on your perspective. > >> Such boxes are technically tuners that output the signle tuned channel. >> They are not "convertors" in the sense they do not convert all the >> digital channels to analog for an older TV to tune. > >I remember in the days of UHF getting more popular, and using >a converter box that output on VHF channel 3. This can be done >with the appropriate mixer and LO, without converting the input >to baseband. It does involve tuned circuits, but does not >convert all (70) UHF channels to be tuned on a (12 channel) >VHF tuner. > >I believe there were/are block converters from cable channels >to UHF which do convert all at once. Most cable boxes don't >do that, though. Early (analog) ones did the down conversion >similar to the UHF conversion described above. Most now likely >go to baseband and then remodulate for those without video inputs. > >The distinction between 'tuner' and 'converter' is fuzzy. >I don't believe that there is a convenient way to block convert >the ATSC input to NTSC output. One could build a box with >multiple tuners, decoders, and modulators but I doubt that >would be for the consumer market. > >The box needs an ATSC tuner, and the logic to convert the >result to an NTSC analog signal. Most likely with both video >and RF outputs. The output of the ATSC tuner is the digital >signal, not suitable for an analog TV, so the box needs >both a tuner and converter. >Which is why the item I describe IS a converter! Mainly... because it HAS ONE IN IT!
Reply by ●October 12, 20072007-10-12
ChairmanOfTheBored wrote:> On Wed, 10 Oct 2007 11:05:46 -0800, glen herrmannsfeldt > <gah@ugcs.caltech.edu> wrote:...>> The box needs an ATSC tuner, and the logic to convert the >> result to an NTSC analog signal. Most likely with both video >> and RF outputs. The output of the ATSC tuner is the digital >> signal, not suitable for an analog TV, so the box needs >> both a tuner and converter. >> > > > Which is why the item I describe IS a converter! > > Mainly... because it HAS ONE IN IT!You have a prick, therefore you are a prick? Maybe so. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
