Image Quality and signal strength?

[BrettD]

I been wondering if the level of a digital TV signal (ie signal strength) has a DIRECT bearing on the image quality thatI see. My SIR-T165 STB shows low to mid-low signals for 1-1, 12-1 and 6-1. The receptor is a Terk TV42 dish-mounted VHF/UHF antenna.
I'm trying to solve a problem where my HD and SD picture is mediocre. SO, if I use a better receptor to improve the signal strength, can I necessarily expect to get much better images on my RPTV?

------------------

[AndrewP]

I think this is one more proof how bad "Terk" stuff is.

Andrew

[tenth_t2]

A better receptor will help.  I experimented with a few different antennas, and ultimately settled on the ChannelMaster 4228, which is a UHF only antenna, on the roof.  I chose this due to it's higher listed gain specification than what I started with, a RS VU-75 in the attic.  A few other factors to think about to get the best signal you can to the T165:

How close you are to the broadcast antenna?

How long the cable run is to the T165 (I believe that standard RG6 cable has a line loss of about -3db per 100' but varies by channel frequency a bit)

How many splits?

I pretty much trudged through all this last year about this time.  For my situation, my cable run was about 100' so I added a pre-amp to compensate for the line loss.  The VU-75 was ok for analog TV, although 12 was ghosty (bad positioning mostly).  However, I also had several splits, so what I saw last winter was a lot of blotchy picture and breakup, it usually didn't drop the picture or audio though.  It was most noticeable in quick action shots, like when they pan the crowd at the beginning of Leno.

My other motivation was that Madison had ABC and CBS at the time, we didn't.  I now can pull those in pretty well most days, but the signal is pretty weak, so conditions need to be right.

So the bottom line is that the signal strength will vary by location.  If you're low, about all you can do is scrutinize each part-- the antenna, the cable run, and splits to get as much signal as possible into the receiver.

Hope this helps!

Greg O.

[BrettD]

I'm within a couple of miles from all of the towers and my downlead is the Terk merged with the Dishnetwork DBS signal and is around if not less than 100'.

[tenth_t2]

Well, you certainly seem to be close enough (although sometimes that becomes it's own problem), and I would think that being much closer than I that your signal at the receptor would be greater (meaning you should be better able to absorb the line losses without impacting picture).

One other thought I had last night was that the Terk 42 is a hoop style element, and your dish is pointed to the southwestern sky, so that could be a funny orientation.

First I'd try taking the Terk off the dish, and try different positions (probably will take two people).  But probably better is to try another antenna-- many have had good success with the RS Bow Tie but they're getting hard to find.  Search-- I recall seeing someone recently finding one locally.

Not to turn this into a bash against Terk, but I've also found their FM antenna products to be not too effective.  They do look nice though...

Greg O.

[LEN]

Originally posted by BrettD:
I been wondering if the level of a digital TV signal (ie signal strength) has a DIRECT bearing on the image quality thatI see. My SIR-T165 STB shows low to mid-low signals for 1-1, 12-1 and 6-1. The receptor is a Terk TV42 dish-mounted VHF/UHF antenna.
I'm trying to solve a problem where my HD and SD picture is mediocre. SO, if I use a better receptor to improve the signal strength, can I necessarily expect to get much better images on my RPTV?

NO, NO, NO!!!
The digital picture you recieve is there or it is not there.  If you do not have enough signal, you will not have a picture.  More signal does NOT affect picture quality!
LEN

[bigcheeshead]

I have to agree with Len there. The picture is all or nothing. Unlike traditional analog, digital  weak signal will get you either no picture or pixalated picture. This is not specific to high def, just any digital signal including cable and satellite.
P.S. The reason digital cable looks so crappy is due to compression not the signal strength.