Welcome to DBSTalk
- Start new topics and reply to others
- Subscribe to topics and forums to get email updates
- Get your own profile page and make new friends
- Send personal messages to other members.
OTA plays great but records pixelated
Posted 07 March 2011 - 02:07 PM
We have a VIP722K DVR. The tech just installed a converter so we could get the local channels with our new outside antenna for over the air local channels.
The local channels have good strength and look great while watching them. When we record them they are pixelated and choppy. I have watched a program live while recording it and it plays great yet the recording is terrible.
Posted 16 March 2011 - 11:56 AM
In order to understand diversity, you must understand multipath distortion.
When a radio frequency (RF) signal is transmitted towards the receiver, the general behavior of the RF signal is to grow wider as it is transmitted further. On its way, the RF signal encounters objects that reflect, refract, diffract or interfere with the signal. When an RF signal is reflected off an object, multiple wavefronts are created. As a result of these new duplicate wavefronts, there are multiple wavefronts that reach the receiver.
Multipath propagation occurs when RF signals take different paths from a source to a destination. A part of the signal goes to the destination while another part bounces off an obstruction, then goes on to the destination. As a result, part of the signal encounters delay and travels a longer path to the destination.
Multipath can be defined as the combination of the original signal plus the duplicate wave fronts that result from reflection of the waves off obstacles between the transmitter and the receiver.
Multipath distortion is a form of RF interference that occurs when a radio signal has more than one path between the receiver and the transmitter. This occurs in cells with metallic or other RF-reflective surfaces, such as furniture, walls, or coated glass.
More via above link.
Posted 16 March 2011 - 12:03 PM
I believe multipath would also affect the live broadcast, not just the recording.
Posted 16 March 2011 - 02:34 PM
I am not a technical guy in this field and would appreciate any help anyone can offer.
Posted 16 March 2011 - 02:48 PM
This is starting to sound like a hard drive problem.
-- My cat's breath smells like cat food.
Posted 17 March 2011 - 11:56 AM
Posted 18 March 2011 - 12:01 AM
I have a 922, which is very much like a 722K with extra stuff... and they share the same OTA tuner module.
I have told Dish repeatedly about a problem with OTA channels... where if I tune from a SAT channel OR especially from a lower-signal level OTA, I find my OTA tuner is either not locking OR locking at a lower than available strength.
Channel 5-01 comes in nearly 100 all the time.
Channel 11-01 comes in nearly 80 all the time.
Both are typically solid at those levels when they lock...
If I change directly from 11-01 to 5-01... I find that 5-01 will breakup and lock at 80 instead of 100... and I have to actually tune to another channel and then back again to lock at the best available signal.
Obviously this isn't something you can do with a timer... because it will change once and lock to whatever it gets.
It looks to me like the OTA tuner is somehow not completely releasing frequencies when it tunes to another OR the firmware is doing something very funky on channel changes... Either way, I find some glitches from time to time in recordings that wouldn't have been there if I had been able to do the workaround watching live.
In your case... if you have a lot of marginal channels... it could very well be that they too are locking at lower than possible signal levels when the timer fires, and then the recording is even more glitchy than mine.
I think there are also issues when using both OTA tuners at the same time where a glitch on one can cause a glitch on the other... but I haven't been able to verify that.
Take a look at all of your OTA channels and their signal levels when you tune to them... then try changing back and forth between some of the higher-signal ones and see if you ever get better signal locks doing that.
IF so... then you could be experiencing something similar to what I've seen on my 922.
-- My cat's breath smells like cat food.
Posted 18 March 2011 - 10:39 AM
OP's problem is very puzzling.
Posted 19 March 2011 - 10:27 AM
Hope it helps.
Thanks for all the help from people on the forum.
Posted 19 March 2011 - 10:32 AM
How far are you from the broadcast towers" Not that it has anything to do with your problem.
Posted 20 March 2011 - 12:03 PM
Posted 27 March 2011 - 03:54 PM