Thread: Satellite guys Exclusive! Mad Scientist! 129 ON BOTH SUPERDISHES!

I have a superdish on 110/119/121 & 61.5 on a dish 500 i see a lot of 105 installs that are working, were is a good start for a 121 superdish.
I also have a spare voom dish and a spare directv dish also whats the best lnb to use for the superdish or is it better to get one of my spare dishs setup and what lnb is the best for one of those dishs

Originally Posted by BFG

everything but HD is qpsk, hd is 8psk

PSK are not usually assigned to a HD or SD channel. HD over the air is 8VSB. read the difference between Q & 8:

8PSK (8 Phase Shift Keying) is a phase modulation algorithm.

Phase modulation is a version of frequency modulation where the phase of the carrier wave is modulated to encode bits of digital information in each phase change.

The "PSK" in 8PSK refers to the use of Phased Shift Keying. Phased Shift Keying is a form of phase modulation which is accomplished by the use of a discrete number of states. 8PSK refers to PSK with 8 sates. With half that number of states, you will have QPSK. With twice the number of states as 8PSK, you will have 16PSK.

Because QPSK has 8 possible states 8PSK is able to encode three bits per symbol.

8PSK is less tolerant of link degradation than QPSK, but provides more data capacity.


QPSK (Quadrature Phase Shift Keying) is a phase modulation algorithm.

Phase modulation is a version of frequency modulation where the phase of the carrier wave is modulated to encode bits of digital information in each phase change.

The "PSK" in QPSK refers to the use of Phased Shift Keying. Phased Shift Keying is a form of phase modulation which is accomplished by the use of a discrete number of states. QPSK refers to PSK with 4 states. With half that number of states, you will have BPSK (Binary Phased Shift Keying). With twice the number of states as QPSK, you will have 8PSK.

The "Quad" in QPSK refers to four phases in which a carrier is sent in QPSK: 45, 135, 225, and 315 degrees.
QPSK Encoding

Because QPSK has 4 possible states, QPSK is able to encode two bits per symbol.

Phase Data
45 degrees Binary 00
135 degrees Binary 01
225 degrees Binary 11
315 degrees Binary 10

QPSK is more tolerant of link degradation than 8PSK, but does not provide as much data capacity.

You really didn't have to type all that

I know what is what and that sd and hd aren't restricted to either.

I was simply explaining that on Dish Network they are only using 8PSK for their HD and QPSK for their SD

Nay, they use QPSK for demo HD channel and before implementing 8PSK used too - just try to find when that 8PSK module came to 6000 and how many HD channels been before that.

I didn't type it all. I had something bookmarked from a while back. I did however like the 8PSK Voom was using on all of it.

P. Smith, the 6000 got the
software

for the 8PSK module 6-12-02. Discovery HD moved to ch 9420/8PSK 7-1-02. The other QPSK
HD channels

were Showtime, HBO, and HD PPV.

Thanks BB, you made best correction to BFG's speedy answer. That's how Dish Encyclopedia should be written .

Originally Posted by Smith, P.

Thanks BB, you made best correction to BFG's speedy answer.

At this point in time, BFG's speedy answer is correct. Let bygones be bygones. Does it matter that some HD was once available in QPSK (and a certain now obsolete receiver was advertised as the only HD receiver one would ever need)?

In today's world, August 7th 2005, dish is using 8PSK only for HD and SD is only on QPSK carriers. Tomorrow that may change. Tune in to the tech chat Monday night and see what they have to say.

JL

I didn't realize I was correcting anybody or that a correction was even needed. BFG is correct about current usage. You are correct that Dish HD used to be at QPSK. BFG had already said he knows that SD or HD can be either QPSK or 8PSK but didn't feel a need to go into the history. In the end, all we've gained is an interesting (or maybe not) bit of trivia.