🚀 go-pugleaf

Ron T. wrote:
> "Ian S. Salisbury" <isalisb@nospam.gmail.com> wrote in message 
> news:g40gku$pn4$1@ftupet.ftupet.com...
>>> I'm just guessing, but you may be able to increase the distance of a 
>>> usable digital signal by increasing the number of parity bits.  Then it 
>>> becomes a matter of how big of a buffer the receiver has, and how much of 
>>> a delay is acceptable.
>> Guess#2  DirecTV sends a digital signal over a pretty big distance, would 
>> an analog signal make it that far without scattering and bouncing and 
>> reflecting all over the place, even interfering with itself?
>>
> 
>> There's some ham operators in here, aren't there?
> 
> Yes
> 
> The digital age has come around long after I got my license, and I've only 
> tracked it a wee bit.
> 
> Hell, I didn't even do packet, and it's been around forever.
> 
> OK.....let me think......you have a signal that is, lets say 10 mv at your 
> location.
> 
> Now, lets say that you have an antenna that is delivering that signal to the 
> receiving equipment at -20 dbm.
> 
> Your receiver is sensitive enough to give you a snowy, but distinguishable 
> video display at that strength.
> 
> Digital requires a stronger signal to read the bits, i don't think it's gonn 
> make it.
> 
> The station engineer that stated, "theoretically a digital signal could go 
> farther", also stated in a second e-mail that, "people who have a marginal 
> analog signal now will probably not be able to get us after the switchover".
> 
> RF is RF....it's simply a medium to carry information. Its' going to act the 
> same, after being affected by atmospheric conditions, sun spots, and 
> physical obstacles no matter what info it's carrying.
> 
Except that digital signals are designed knowing that some of the data 
is going to be lost.  They use parity checking and buffers at the 
receiving end to make the best attempt at putting the whole signal 
together.

I was responding to the theoretical aspect of it, not the real world.

If you lived at the very outskirts of the signal and you recorded an 
hour worth of data, the parity bits would tell you which packets are 
bad.  If they sent the same data stream again, and you had enough 
buffers to replace the bad packets, you would have as good of a 
recording as someone next door to the transmitter.

It's the same reason you can scratch the hell out of a CD and it will 
still play. (until you scratch out too much parity info)

But in the real world, they only send a little redundant data and the 
buffers in the receivers are only big enough to handle a few seconds of 
it, if that.

And my question from guess #2, is really; could you actually broadcast 
an analog TV signal from NY to LA with enough juice?  We know that audio 
can in the AM band, but what about Video in the UHF?