Originally Posted by blackcat6
Not absolutely true. A RF issue can reduce the signal quality to the point where the error correcting routines can't reconstruct enough of the data stream to make mpeg decompression, possible for a HD picture, while at the same time it would be OK for SD. 18.1 is firstname.lastname@example.org while 18.3 is email@example.com or rather 18.1 requires more than 5X as much data/frame than MeTV. TVs have very limited buffering/processing power and will drop frames HD frames faster than SD. Lock is lost and it has to try again.
I would rule out issues with the receiving equipment since he is seeing the same problem on more than one device.
If it isn't an RF issue, then the suggestion to look for a better antenna isn't going to fix anything. In this case the guy above might be right when he says that 18.2 is somehow corrupting the WCCB data stream. IMO, I don't think this is right, but since you are the expert about this station, maybe you could offer up something better.
That is in-correct and your lack of experience in telling two Engineers they are wrong is just wonderful..
First off, it does not matter if it is QAM or 8-vsb for the ATSC tuner. Second we can have for instance a 256-QAM with 2 HD streams and 3 SD streams (typical TWC) even if the RF signal is low only two items look at the quality of the stream one the MER, second the BER. MER is the C/N along with some of other items like EVM, BER is measuring the quality over a predetermined time. Both MPEG types HD & SD will react the same when a cliff effect is reached in the quality= they are the container in that QAM. It does not matter if one is 3.2Mbit/s and the other is 12Mbit/s, they wil react the same to quality.
ATSC is the same way with MER/BER, but an important tool to use here is a visual constellation-eye chart. This will show the I/Q constellation and the eye chart which is great because when the eye collapse's so does the quality regardless of the 8-VSB signal having two containers one 13Mbp/s the other 3Mbp/s or not.
What I am getting at for both of these Modulations is the MER which gauge's C/N in a digital ATSC/QAM signal will react in kind to any type of MPEG stream regardless of container size.
Below is a visual of a 8-VSB constellation/Eye chart. For what it is worth Blackcat I did work for TWC in the past and dealt with local Television Engineers about impairments and what could be done to improve them, For months you complained about issue's in the past with regard to reception problems and felt in was the Transmitting stations issue not yours.? For some reason when people on this forum gave you input to solve your problem you would not listen in kind. Now you have noted that you are a retired from the electrical field, how could you trouble shoot those issue's with our a VOM or amprobe.? Same goes for this field get some used test gear or another good item since you are using tuner cards is TS-Reader and start actually looking at MPEG transport instead of theorizing about it.