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Discussion Starter · #1 ·
Hey guys,


I am a pretty tech savvy individual, but when it comes to TV transmission, tuners, etc I get kind of lost.


So, we subscribe to Comcast Digital cable with On Demand. In order to get the menu system and the on demand, we are using the rather large Motorola setup box on our main TV (a new LCD HDTV).


However, we have two other TV's in our house (both new Samsung HDTV's). They both have ATSC/QAM tuners. For these two TV's we are plugging directly into the wall outlet (no set top box or converter). It tunes channels, and many of them are listed as digital (DTV).


Here's where my questions come in.


1. What exactly is clear QAM and does one actually need to subscribe to a cable package to receive it?


2. Comcast wanted us to get one of this converter boxes (model number DC50x). Image . What exactly would this do? It is of my understanding that you only need this for analog TV's, correct? If so, then I do not need one for my QAM-enabled HDTV? Maybe a better question would be, when does a QAM HDTV need a digital box, if at all?


3. What exactly is the DC50x and if I don't use the DC50x on my HDTV, am I missing anything?


4. The switchover that happened earlier this year was for over-the-air transmissions only, correct? If so, what is a DTA and how does it differ from the digital converters that the coupons were for?


Thanks, and sorry for the "noobness" of my questions.
Any info is greatly appreciated
 

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Discussion Starter · #2 ·
Ok, after continued research I have answered a couple of my questions.


Currently, I can tune all the digital/analog channels that I subscribe to using my TV's built-in tuner (I don't have to use the Pace DTA). When Comcast started switching over to digital, old analog TV's will need the DTA, but QAM TV's do not. However, this is only because the FCC is requiring Comcast to broadcast these channels (previously called expanded basic but now called Digital Starter [30-80]) in clear QAM. However, this can change in the future. So for now, I am good with the built in tuner.


Is that right?
 

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Quote:
Originally Posted by AhrenBa /forum/post/16985424


1. What exactly is clear QAM and does one actually need to subscribe to a cable package to receive it?

QAM is an efficient means of transmitting digital television signals. "Clear" QAM is just a short-hand for referring to QAM signals that are not encrypted. Generally, it isn't QAM that you subscribe to: You subscribe to receive certain service offerings, and those service offerings may be delivered by QAM. And what is encrypted will vary from place to place. The only requirement for providing unencrypted service is that service providers must provide one signal (broadcaster's choice) for each local broadcast channels. There is no requirement to provide unencrypted service for cable channels.

Quote:
Originally Posted by AhrenBa /forum/post/16985424


2. ... when does a QAM HDTV need a digital box, if at all?

The issue you raised pertains to the difference between a regular cable set-top box (STB) and a cable digital terminal adapter (DTA). DTAs are currently prohibited by law from doing any kind of decryption (because they do not support separable security), without a waiver from the FCC. Therefore, generally, anything you can receive via a DTA you can receive on your HDTV if it has a QAM tuner. However, you will not receive those channels on the channel number that the cable company publishes, but rather on a specific QAM frequency which will have nothing to do with the channel number that the cable company publishes. You'll basically need to discover the mapping on your own, and recognize that it will change over time without notice. This is normal and completely within the provisions of the law.

Quote:
Originally Posted by AhrenBa /forum/post/16985424


3. What exactly is the DC50x and if I don't use the DC50x on my HDTV, am I missing anything?

See above.

Quote:
Originally Posted by AhrenBa /forum/post/16985424


4. The switchover that happened earlier this year was for over-the-air transmissions only, correct? If so, what is a DTA and how does it differ from the digital converters that the coupons were for?

Totally unrelated. The switchover that happened earlier this year pertained to over-the-air transmissions, and the digital converters that the coupons were for were ATSC/8VSB tuners, not QAM tuners. Over-the-air stations were not able to use the more efficient QAM technology because sending signals through the air makes the subject to a lot more interference, as compared to sending signals through a wire.
 

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Quote:
Originally Posted by AhrenBa /forum/post/16985578


When Comcast started switching over to digital, old analog TV's will need the DTA, but QAM TV's do not. However, this is only because the FCC is requiring Comcast to broadcast these channels (previously called expanded basic but now called Digital Starter [30-80]) in clear QAM. However, this can change in the future. So for now, I am good with the built in tuner. Is that right?

Assuming you don't have any premium channels, or perhaps even just a higher tier of expanded basic, probably. There is no hard-and-fast rule about where you go from needing DTAs to needing STBs. For example, I suspect that, once the transition happens here in October, we'll be able to get (let's say) USA Network via unencrypted QAM, but we won't be able to get BBC America that way (because the latter in one tier above expanded basic).


Also, a lot of people seem to be convinced that Comcast will be successful in getting the waiver I mentioned above. I am not sure why they're convinced, but they are.
 
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