Smart converter boxes?

n2rj

Moderator
Staff member
#1
Today I dusted off the Apex DT250 and connected to an older TV in a spare bedroom. My dad's going to be visiting over the summer so I want to give him both OTA and cable options on the TV (cable doesn't carry all of the local channels. They even dropped one channel claiming they couldn't receive it after the analog shutoff!)

When I was doing the channel scan, it did a short "scanning" sequence without displaying actual channel numbers, then jumped way ahead percentage wise and scanned 2-51. That's right. 2-51. It skipped from 51-69 and finished the scan. It also stayed on some channels longer than others, and quickly skipped blocks of channels as if it knew which channels would have a signal in this area. It also missed out WNJJ-LD on channel 41 which is the strongest signal here (receivable indoors with a paperclip in the antenna socket!)

So my question is this - is there some sort of a signal it receives that tells it which channels are live in this area? Some sort of datacast it gets from one or more channels?
 

Tim58hsv

DTVUSA Member
#2
It also stayed on some channels longer than others,
My Zenith converter does that when it tries to lock onto a weak channel like the ones from Columbus, Ohio. Those stations are too far away to get a picture from most of the time but the box still receives a low signal.
 

n2rj

Moderator
Staff member
#3
I understand for the weak signals it will try and then timeout, but it skipped really fast in known white spaces and skipped 52-69 really fast too. Something is telling it not to scan those channels.
 

Trip

Moderator, , , Webmaster of: Rabbit Ears
Staff member
#4
If it can't detect even the hint of a pilot carrier, it'll just move past it, whereas if there's a weak signal, it'll linger there trying to get a lock. There's no magic signal telling it whether or not there's a station present, I suspect this box just rejects channels without pilot carriers very quickly.

- Trip
 

Piggie

Super Moderator
#5
It also missed out WNJJ-LD on channel 41 which is the strongest signal here (receivable indoors with a paperclip in the antenna socket!)

So my question is this - is there some sort of a signal it receives that tells it which channels are live in this area? Some sort of datacast it gets from one or more channels?
This might be the clue, so strong you only need a paper clip, and it might be distorted going into the box by too much signal from an amp or too much antenna. Just a guess, but it popped out at me reading and commented.
 

n2rj

Moderator
Staff member
#6
If it can't detect even the hint of a pilot carrier, it'll just move past it, whereas if there's a weak signal, it'll linger there trying to get a lock. There's no magic signal telling it whether or not there's a station present, I suspect this box just rejects channels without pilot carriers very quickly.

- Trip
Hmm. Not really based on what I see. I'll post a video of it.
 
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