[wejones]

Originally Posted by siliggy

PID Question:
G'day. Could someone please comment on the " Manual PID scan function"
and or this statement from the blurb "The M-II is one of the few consumer receivers that will identify the frequency, symbol rate, polarity, FEC and even the PIDS"

In Australia there are several channels that most recievers cannot find. They have hidden PIDS. Entering the correct frequency and symbol rate even FEC will not get them even if a good signal shows because the signal does not contain the PID information. Manualy entering or editing the PID values will get them on some recievers but not all. Thats great if you already know they are there.

Does the Mercury II find them on it's own?

As Rainman mentioned, if you want to understand more about the satellite signals, a PCI card receiver and the TSREADER program is really educational. I didn't know anything about how these signals were transmitted until I started looking at TSREADER, and it really helps.

Most sat signals have a bunch of data packets coming down, each type packet is identified by numbers, ie PIDs. When a receiver is told to scan a transponder, the first thing it does is look for a stream of packets called the PAT, or program allocation table. The PAT has a list of PIDs for streams called PMTs, which are program map tables. Basically each PMT defines a channel. Each PMT will generally list the PID#s of the video and audio streams for that channel. Once the receiver has read the PAT and PMTs, it can then store a list of channels with the corresponding VPIDs and APIDs.
However, some sat signals, such as the WB (CW) transponder on G11, don't have either the PAT or the PMT streams, so there is no way for the receiver to figure out which streams have the video and which streams have the audio for each channel. However, if the receiver has an advanced scan option or manual PID scan capability, you can enter that info yourself for each channel, ie tell the receiver what the audio and video PID #s are for each channel. Then, the receiver can scan in the channel.
In the case of the CW transponder, there is no PAT and no PMTs. On some other transponders, they have a PAT, which may list some channels, but the PMTs may be missing for other channels. On still other transponders, there may be both PAT and PMT, but the PMTs may be missing the PID information, so the receiver can't figure out what to do.
This is all easy to see when you run TSREADER.

Re the blurb about the "The M-II is one of the few consumer receivers that will identify the frequency, symbol rate, polarity, FEC and even the PIDS" , that really doesn't seem that unusual to me. In the past, if you knew the frequency and symbol rate, most receivers would figure out the rest, however now most receivers have a blind scan or power scan that figures out the frequency and symbol rate. So compared to a few years ago it may be one of the few, but compared to current models, it is pretty much the same features that other receivers have. The only unusual feature I've noticed about the M-II is that it has component output, whereas most other receivers only have composite video. This does give better video if you have an HDTV with a component input. If you use the composite output though, the M-II video is no different from other receivers. I wish I could use the M-II into my new HDTV, however I still haven't figured out how to get audio from AC3 channels, other than running to a separate stereo. So my Mercury-II is still sitting there un-used for the most part.