I can't see NBC with the digital conveter box

Ok This is what I found out and hopefully found your solution..
Have you heard of Double Rescan?
The Federal Communication Comission Designed a Process called double rescan.
Double Rescanning erases and thenreprograms the channels in the converter box an digital TVs memory.
To Double Rescan, you will first need to disconnect the antenna from the converter box or antenna.
Then disconnect the converter and or digital tv power supplies from the wall. Wait a minute before plugging them back in. The antenna should still be disconnected.
With the antenna disconnected run the channel scan function on the coverter box or digital tv. When the scan completes you will have completely removed any channel data the converter box or digital tv, had in its memory.
Now it's time to rescan for real.
Do this by reconnecting the antenna to the converter box or digital tv and running the channel scan function again.
Thus the double rescan is born.
If the double rescan doesn't work, then try some tips and tricks to get your converter box up and running..I will have to look up the url again that has the tips and tricks...
If the double rescan doesn't work let me know and I will look up more options..
I really hope this works..

Not sure how you are connected to receive the signal, but if you are not using a cable box and going off air, then either the signal is not coming in from NBC, or your antenna needs adjustment. IF its over the air, its also a digital signal which will tune to lets say channel 4. For digital it will be 4.1 or 4.2 etc.
If you are using a cable/sat box to then connect to the TV, call the provider and ask.

Are you sure the converter box is working properly and that you can recieve the signal?

Very easy to find out just plug it in.Have an antena,get picture ur tv work with digital,their no more analog signal out there.

try doing a rescan of the channels, might also be new RF signal obstruction in the area, try re pointing your antenna a different angle, this helped me once when a weak channel was freezing often.

If you are receiving digital signal and channel is fuzzy, something wrong. Only Analog signal is fuzzy. With Digital it is great picture or nothing. For channel 6, check to see if they are broadcasting in digital yet. If they are not, this is why you are not getting a signal. If they are broadcasting in digital, then you need a stronger antenna.

What type of antenna are you adjusting? If it is not a UHF then you will have to try another such as a Smart Antenna or one from Wal-Mart for digital TV.

That just means that stations you can't pick up while the box is on are not broadcasting digital signals yet. Most will be after February.

http://www.urc.philips.com/

check any SAP settings in the menu