Archived from groups: alt.tv.tech.hdtv (
More info?)
He asked if it's normal for a TV to 'hang' (like a Windows PC after a
Windows program or O/S crashes) after tuning a bad channel. The
academic answer is 'NO'; a *properly* designed/tested/working tuner
should *NEVER* lockup just because the station-signal is weak or garbled.
But the reality, confirmed by many on avsforum.com, is that *many*
ATSC tuners glitch or lockup when tuning a weak-signal. If there's *NO*
signal at all, the tuner's decoder skips it and moves on. But if the
signal is weak, the tuner tries to 'decode' the signal, and that's the
failure-point.
The firmware (or maybe it's the hardware) is pretty lousy, and the
firmware will wait forever to get the decoded statistics for the channel
(format, program-guide info, etc.) On a *good* signal, this takes a
split-second. On a garbled or weak signal, this can take upwards of
seconds.
In my area (Los Angeles, CA), two ATSC broadcasters (KRCA-DT/68 and
KLCS-DT/41) multicast up to 4 channels atvarious times of day.
During other times, only 2 channels are actively broadcast (but
all 4 are still in the PSAT/PSIP table accompanying the broadcast.)
What's the problem? Well the 'absence' of a real signal causes many TVs
(like Samsung's built-in tuner HDTVs) to 'freeze.' They reach the
subchannel, look for a valid MPEG-stream, then sit there endlessly
waiting. Fooling around at Circuit City, I tried to change the channel
(after tuning this 'phantom'), and the TV responded like 15-20
seconds later. But at least it responded...
It was obvious to me the firmware was badly written. It reminds me of
the earliest DVD-players. If they encountered a dirty/scratched DVD,
the player would stutter and/or lockup -- the remote would stop
responding. The modern DVD-players have better firmware, and the
'eject' button acts like a 'RESET' button. (At least it does on my $50
DVD-player
hdtvfan wrote:
> Simple, you answered your own question. You need more signal.
> A outdoor UHF only antenna should help. A antenna mounted UHF
> pre-amp using RG-6 coax may be needed if the stations are 40 to 60
> miles away.
>
> hdtvfan
>
> On 21 Aug 2004 21:43:04 -0700, inkyblacks@yahoo.com (inky blacks)
> wrote:
>
>>Does your tuner ever lock up?
>>
>>My set is a Toshiba 51HX93 with what I think is a built in 4th
>>generation LG ATSC tuner. If I do not get a strong signal, my receiver
>>chip loads up and the set goes black after a few seconds of trying to
>>move around the indoor antenna. Then I have to turn off the set and
>>unplug it as well to clear the memory before I can get a picture
>>again.
>>
>>Do other people have this problem or is my set defective?
>>
>>Is this something a repair man can fix or is it endemic to all Toshiba
>>RPTVs?
Unfortunately, I don't have your particular TV, so I can't answer that.
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