Capturing Broadcast TV Signals

[stickboy1375]

All cable companies are claiming all digital channels.

Well, now we are mixing two cans of worms together. There are two separate and unrelated things that some people get confused:

1) The Digital Transition of the broadcast or over-the-air TV that you receive with an antenna. This is what we have been discussing in this thread. Nothing to do with cable or satellite.

2) The elimination of analog by the cable companies. Even though over-the-air broadcasts are digital the cable companies will convert them to analog, so if you have cable nothing will change.

For now.

The cable companies want to eliminate those analog channels because they are bandwidth hogs and they are running out of room. They can put up to ten digital channels or three or four HD channels in the same space as one analog channel so the switch to digital is a no brainer. Kinda like compressing your computer HD when it runs out of room.

When this happens every TV on cable will either have to have a digital tuner (which all do that have been manufactured in recent years) or a cable box for the TV just to work. A cable box will be required in most cases to get the premium programming, pay-per-view, etc. just like now.

Some cable companies have timed their own change to digital to coincide with the Digital Transition. There are lots of theories as to why, some good, some nefarious.

-Hal

Thanks Hal.

 

[egnlsn]

All cable companies are claiming all digital channels. so what gives? I'm just going to wait and see for myself.

Hal gave an excellent explanation. Let me just add that most large cable companies are doing ADS (Analog Digital Simulcast), which is the duplication of the analog channels in digital format. The settop box has all of the channels below 100 mapped to their digital counterpart, so that when you select channel 2, rather tuning to 54MHz the box tunes to the frequency where the digital transmission of channel 2 is located. Eventually, they will start taking the analog channels off the system, and if you have a box, you will never know it. Most likely, a dozen or 2 analog channels will remain (locals, QVC, stuff like that) for some time.

 

[grich]

The Des Moines stations that are analog VHF will go back to their VHF channels for digital after the switch.

Grich, egnlsn, if you dig down in rabbitears.org it looks like when they do they will be greatly reducing their power.

Isn't that in keeping with only allowing low power stations to remain in the VHF band?

-Hal

The intent of the FCC was to give stations the same coverage area with digital transmission as they have with analog. Since it takes less power at VHF frequencies to achieve a given coverage area than at UHF frequencies, many stations elected to return to their original VHF channels. The FCC computer models have shown some stations can replicate their analog coverage area with less power transmitting in digital. Let's hope they're right.

An extreme example...Channel 5 in Des Moines transmits 100kW analog. They are returning to channel 5 after the transition. Their digital license is calling for only 11.5kW. Since low-band VHF channels (2-6) are more prone to skip and electrical interference, many people are worried that a low-band VHF DTV signal just isn't going to hold up in electrically noisy environments. Most low-band stations are moving to either UHF (14+) or high-band VHF (7-13) for their final DTV channel assignment.

I haven't visited rabbitears.org...I may do that tonight.

 

[hbiss]

The FCC computer models have shown some stations can replicate their analog coverage area with less power transmitting in digital.

Ahh. I was wondering how they could cut their ERP from 100Kw to 11.5Kw and the coverage area stayed the same.

I've got a bridge I want to sell you too.

-Hal

 

[grich]

Ahh. I was wondering how they could cut their ERP from 100Kw to 11.5Kw and the coverage area stayed the same.

I've got a bridge I want to sell you too.

-Hal

I'm glad I don't work for that station. :smile: