# Picture quality problem with the 721



## kjvella (Jun 19, 2004)

Hi. I recently upgraded to a 721. The picture quality is not as good as it was on the 301. I am seeing lines going from right to left on the TV set. Those lines didn't appear when the 301 was connected to the TV set. Dish's Advanced Tech said it was probably a cable issue. The installer is coming back next week to check the cable connections. Is it possible that the new cable line that they put in for the second tuner may have been damaged?


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## SimpleSimon (Jan 15, 2004)

No, this sounds like the connection from your 721 to the TV. How are you hooked up? Try jiggling your cables and/or swapping them out.

To be sure, use the Point Dish screen to check your signal strengths on both tuners and an assortment of satellites and transponders. If they're reasonably high (Green bar) and not fluctuating, you should be OK there.


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## kjvella (Jun 19, 2004)

Thanks for the help. I will try that tonight after work.


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## Big Bob (May 13, 2002)

also, it may be a grounding problem. (there is a lot of that going around lately )Try lifting the ground with a 3-prong to 2-prong adaptor.
Also, try unplugging anything else plugged into the 721 and your TV. If the lines go away, plug them back in one at a time to find the offender


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## garypen (Feb 1, 2004)

Usually, ground hum appears as a horizontal bar that moves vertically up the screen, not right to left.


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## Big Bob (May 13, 2002)

garypen said:


> Usually, ground hum appears as a horizontal bar that moves vertically up the screen, not right to left.


not on my system. YMMV

It is an easy thing to check for and eliminate in your troubleshooting routine.


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## kjvella (Jun 19, 2004)

Big Bob said:


> not on my system. YMMV
> 
> It is an easy thing to check for and eliminate in your troubleshooting routine.


Satellite's Unlimited came out today to fix the problem with the picture quality. The repair guy was very helpful, and he solved the problem in about 10 minutes. He ended up taking the cable out from the 721 to the receiver and replaced the cable with RCA wires. He said that the 721 was designed to work better with the RCA wires, and he was right. The quality is 100% better now. Thanks to everyone for the help. I appreciate it.


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## kmcnamara (Jan 30, 2004)

So you had your 721 connected with coax? No wonder you were having problems. Did you also realize that the coax output does not contain stereo audio? Using RCA, you'll also get stereo.


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## mindwarp (May 19, 2003)

and check if you have in your tv s-video inputs, and if you are using them, because pq will improve a lot.


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## Slordak (Dec 17, 2003)

You'd be amazed at the number of "big screen" TVs (or even HDTVs) with nothing hooked up to them but a single sorry black coax wire. Folks are often used to smaller, cheaper TVs, where this is the only input, and don't know any better when they have better input options available.

Personally, I'd be fine if my TV had no analog tuner and no coax connection at all, but this hardly seems to be the majority view point...


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## garypen (Feb 1, 2004)

kjvella said:


> He ended up taking the cable out from the 721 to the receiver and replaced the cable with RCA wires.


D'OH! :bang


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## jmbrooks (Jan 11, 2004)

That's odd, I just started using the coax output (gasp) to send the signal to my other TV's (so I can watch PVR events on any TV) and the PQ is fine. Since the house was not wired with A/V (yellow/red/white RCA), I had to use the installed RG6.

I deactivated the old 3900 receiver in my bedroom. Both the 501 and 721 reside in the living room with the best connections available to my primary system (s-video & optical audio). This way I have a total of 3 tuners. Doesn't happen very often, but there are times when I want to record 3 programs at the same time. Each recievers coax output is fed to an A/B switch and then out through a video splitter to the other 2 TV's in the house, works nicely and allows great flexibility with less equipment. Sure glad these receivers send the audio/video to all outputs simultaneously.

Now where am I gonna put that HD receiver when I finally get one??


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## TomCat (Aug 31, 2002)

garypen said:


> Usually, ground hum appears as a horizontal bar that moves vertically up the screen, not right to left.


Which makes me think that this is not a ground loop problem. That is caused by grounding connected equipment separately to individual grounds with slightly different ground potential, and then connecting the equipment chassis to chassis via the shield of the interconnecting cable, which can then induce 60-cycle hum into the picture. It rolls upward slowly as GaryPen says, due to the beat pattern between 60 cycles (AC) and 59.94 cycles (NTSC). If you see the same thing with 2 rolling bars (120-cycle) it could be failing filter caps in the PS or another manifestation of the first (ground loop) problem.

If you are seeing what you describe, the more likely cause is a bad ground (poor shield integrity on the signal cable) or poor shileding in the 721 itself allowing interchassis interference, either of which can allow local pickup or ingress of a second signal competing on (nearly) the same frequency (in this case probably on channel 3). Since the local pickup is slightly different in frequency than the difference between 60 and 59.94, it will sometimes present as horizontal rolling or diagonal lines instead of the slow rolling hum bar.

Tightening or replacing wires is a good fix, but moving to baseband is better. Not only does it remove the arena for signal competition, it increases PQ, allows stereo, and just plain works better.

Hmmm. After re-reading this, I might switch to decaf.


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## garypen (Feb 1, 2004)

TomCat - I knew I was correct about video ground hum. I didn't want to argue with Big Bob. (Maybe if he was _Little_ Bob, I would have. His avatar is pretty scary too. WTF is that?)

The guy's problem was solved though, when he switched to composite instead of RF output. It sounds to me like he either had a bad RF modulator in his 721, a bad RF cable, or a serious amount of RF interference in his home. Definitely not ground hum, or it would have continued, even after switching cables. (Also, what are the chances of two pieces of equipment in the same location being plugged into two different outlets with two different grounds?


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## riekl (Jan 21, 2003)

garypen said:


> TomCat - I knew I was correct about video ground hum. I didn't want to argue with Big Bob. (Maybe if he was _Little_ Bob, I would have. His avatar is pretty scary too. WTF is that?)
> 
> The guy's problem was solved though, when he switched to composite instead of RF output. It sounds to me like he either had a bad RF modulator in his 721, a bad RF cable, or a serious amount of RF interference in his home. Definitely not ground hum, or it would have continued, even after switching cables. (Also, what are the chances of two pieces of equipment in the same location being plugged into two different outlets with two different grounds?


Odd my bedroom TV always has these diagnol lines (top right to bottom left) and i was told it was a ground loop .. tried all kinds of filters was never able to resolve it so i just live with it.


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## garypen (Feb 1, 2004)

Diagonal lines are not caused by ground hum. It sounds like some kind of induced noise, such as from a generator, transformer, motor, or appliance, maybe your fridge or flourescent lighting?

If the TV has these lines, even if it is not connected to anything else such as cable, vcr, dvd, etc, it's not ground hum. You can disconnect everything from the TV, and see if it still does it.

Ground hum is caused by voltage differential between two different grounds, which can only take place when you have two different pieces of equipment plugged into two different power sources, which have two different grounds. A single device, plugged into a single power source, with a single ground, cannot have ground hum.


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## Big Bob (May 13, 2002)

garypen said:


> I didn't want to argue with Big Bob. (Maybe if he was _Little_ Bob, I would have.


Wise move.


garypen said:


> His avatar is pretty scary too. WTF is that?)


An image captured by Hubble. I don't remember exactly what it is (was). Something really big blowing up. I like it for some reason.

As for ground problems, I didn't think this was a ground problem, but I was shown to be wrong once, so I thought it was worth checking out. It is so easy to use a ground lifting adapter, it is worth the 1-2 minutes just to see what happens.

Even though in theory this shouldn't be a ground problem, I have yet to see a theory that encompasses all of the weird and wacky ways that grounding problems can present themselves.

When troubleshooting, I like to eliminate the possibilities that are easiest first. Lifting the ground is one of the first ones I try as it is just so easy to test, and sometimes it actually is the problem.


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## garypen (Feb 1, 2004)

Big Bob said:


> Lifting the ground is one of the first ones I try ...


Sure. For a guy named Big Bob, lifting the ground must be easy. I saw Superman do it once in a movie.

BTW, that avatar looks like a severed, tattooed head.


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## kjvella (Jun 19, 2004)

mindwarp said:


> and check if you have in your tv s-video inputs, and if you are using them, because pq will improve a lot.


Thanks for the advice. I went to Wal-Mart and found an updated "Automatic Audio/Video Selector With RF Modulator" by Philips. That modulator allows me to connect up to FOUR components (including S-Video) to my TV. I also purchased the S-Video cable from Philips with 24K Gold series technology to connect the 721 to the modulator. AWESOME DIFFERENCE!!! It is like having a new television set. I would highly recommend this solution to everyone. The total cost with tax was only $40.23.


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## kmcnamara (Jan 30, 2004)

If you're not connecting the S-video cable from the 721 directly to the TV, you're not getting the real benefit of S-video. I'm sure it's an improvement over what you had before, but it's not real S-video. What kind of cable connects the modulator to the TV? Coax?


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## kjvella (Jun 19, 2004)

kmcnamara said:


> If you're not connecting the S-video cable from the 721 directly to the TV, you're not getting the real benefit of S-video. I'm sure it's an improvement over what you had before, but it's not real S-video. What kind of cable connects the modulator to the TV? Coax?


Yes, a coax runs from the modulator to the television.


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## SimpleSimon (Jan 15, 2004)

kjvella said:


> Yes, a coax runs from the modulator to the television.


Arrgghhh. That's worse than RCA cables which are worse than S-Video which is worse than Component, etc., etc.


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