Channel 4.1 signal strength?

[Stanley Kritzik]

So, today being Wednesday, we did our thing, and the results follow.  To first set the scene, I have a Winegard amplified Square Shooter about ten feet in the air, aimed generally at the antenna farm in, and around Estabrook Park -- distance about five miles.  I'm aiming through a well-leafed maple tree which is about 100 feet away from the antenna.  As I started measuring, the face of the antenna was tilted back from the vertical about 30 degrees.

I felt pretty certain I was aimed properly (with 6 and 12 both close to 100%), so I started by increasing and decreasing the tilt.  The more I increased the tilt, the better my results, so I quit the process at about 60 degrees.  The % results on my DirecTV HR21 are as follows:

Channel                  30 Degrees               60 Degrees
 4-1                                   60%                       78%
 6-1                                   99%                      100%
10-1                                  85%                        85%
12-1                                  95%                        95%
18-1                                  60%                        72%
36-1                                  82%                        85%
58-1                                  94%                        95%

It would appear that the flatter to the horizontal I make the antenna lie, the better the results.  I didn't push things further, as I felt that the amount of improvement would be enough; we'll watch some Olympics, and see what happens.  Also, D* is now broadcasting 4-1 from the satellite as "4", so I have backup options.

I don't know why 4-1 is relatively low in any case.  Some of the other channels have whopping tall towers, but i assume TMJ is right in there with power, etc.  Anyway, that's it for now, and I'll mention some results in a few days or a week.

Stan

So, after feeling comfortable with the improved signal strength for 4-1, I went to bed some time after midnight, and my wife had the Olympics on CH 4 from DirecTV.  I switched to OTA 4-1, and -- nothing (searching for antenna signal, etc.).  After all that work, I panicked.  So, I measured the signal, and it was zero.  Then I realized that TMJ's transmitter was off the air, but their feed going to DirecTV (and, probably, TimeWarner) was working.

Next morning, all was well, and I think I'll leave things just as they are; wait for big rains and snows; and see how everything goes.

Stan

[AA9VI]

Something is definitely up with their output power.  WTMJ-DT is much weaker than a month ago.  I haven't been able to get it 99% of the time like I used to during the last year.  Did anything happen within the last month?

[RonH]

I was futzing around with antenna wiring today and so I revisited the signal strength for 4-1.  I get similar results, 100% on everything except for 4-1, which comes in around 85% on the AM-21 Directv box and 62% on my pioneer's internal tuner.  I think the pioneer is more picky, as it has "level" and "quality" meters, not sure what the difference is.

When I first got the AM21 in May, 4-1 was 100% on the AM-21.  So I have seen similar results in that 4-1 has the weakest signal.

[Bebop]

I'm getting 100% on my tuner for 4-1.

[Nels Harvey]

I think the pioneer is more picky, as it has "level" and "quality" meters, not sure what the difference is./QUOTE]

The Pioneer receiver is showing you both RF signal levels and 'Quality of signal', or figure of merit, showing what the error rate on digital decoding is.

The RF level tells us how strong the signal is in arriving at the receiver.  That can be improved with better antennas, better aiming, and/or a preamp in the feedline.

The Quality meter is showing how well it is being decoded.  Factors for that include multipath, or other interference.  Receivers showing only one level reading generally are just showing 'quality'.

A receiver several miles out with a good antenna can get a very good quality reading, even with lower RF levels.  Someone close in can have high RF levels coming into the receiver, but the quality reported can suffer if multipath reception exists.

In other words, the signal level reported on most receivers is NOT an 'S' meter like on a communications receiver.

If you think about it, Quality is what reception is all about.  That's why it is the predominant signal reading used on most receivers.

Nels....

[Bebop]

This is a very good explanation of Signal vs Quality.

http://www.silicondust.com/forum/viewtopic.php?t=4474