[mythtv-users] ATSC channel not detected with ATI TV Wonder 600

Will Dormann wdormann at gmail.com
Fri Jan 3 18:36:18 UTC 2020


On 1/3/20 11:43 AM, John Pilkington wrote:

> https://nocable.org/browse-stations/callsign/wpxi-pittsburgh-pa
> 
> WPXI is scheduled to start its repacking process on 4/13/2017 and finish
> on 8/2/2019. After the repack, the RF channel (not digital) will change
> from 48 to 23. This means that to continue to view WPXI, you will need
> to rescan your TV after that scheduled completion date.



Hey John,

Yeah, the repacking is what was described in the original link I sent.
As far as I'm aware, the RF channel seems to be mostly irrelevant when
tuning ATSC with a digital tuner.   For example, here's the relevant
w_scan output for another local station, KDKA:

-----
$ w_scan -fa -A1 -x | tee dvbscan.txt
w_scan -fa -A1 -x
w_scan version 20141122 (compiled for DVB API 5.10)
using settings for UNITED STATES
ATSC
VSB US/CA, DVB-T TW
scan type TERRCABLE_ATSC, channellist 1
output format initial tuning data
WARNING: could not guess your codepage. Falling back to 'UTF-8'
output charset 'UTF-8', use -C <charset> to override
Info: using DVB adapter auto detection.
	/dev/dvb/adapter0/frontend0 -> TERRCABLE_ATSC "LG Electronics LGDT3303
VSB/QAM Frontend": good :-)
Using TERRCABLE_ATSC frontend (adapter /dev/dvb/adapter0/frontend0)
-_-_-_-_ Getting frontend capabilities-_-_-_-_
Using DVB API 5.10
frontend 'LG Electronics LGDT3303 VSB/QAM Frontend' supports
INVERSION_AUTO
8VSB
QAM_64
QAM_256
FREQ (54.00MHz ... 858.00MHz)
-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_

<snip>

539000: 8VSB(time: 00:09.816)         signal ok:	8VSB     f=539000 kHz
(0:0:0)

<snip>

tune to: 8VSB     f=539000 kHz (0:0:0) (time: 03:06.319)
        8VSB     f=539000 kHz (0:0:0) : updating transport_stream_id: ->
(0:0:2501)
service is running. Channel number: 2:1. Name: 'KDKA-HD'
service is running. Channel number: 2:2. Name: 'StartTV'
service is running. Channel number: 2:3. Name: 'DABL'
-----


According to this page
<https://www.rabbitears.info/market.php?request=print_station&facility_id=25454>,
KDKA is channel 25.  And cross-referencing with
<https://www.sigidwiki.com/wiki/ATSC_Broadcast> I see that the lower
edge of channel 25 is 536 MHz.   Add 3 (half of the 6 MHz bandwidth),
and you get 539 Mhz, which is exactly what w_scan reports above.

Now let's look at WPXI's new channel 23.   In the same table above,
channel 23 is 524 MHz + 3 = 527 MHz.

Here's the relevant line from w_scan for the WPXI frequency of 527MHz:
527000: 8VSB(time: 00:48.319)         signal ok:	8VSB     f=527000 kHz
(0:0:0)

But if I look later in the w_scan output where it tunes to the "signal
OK" frequencies, it seems to not find anything:

tune to: 8VSB     f=527000 kHz (0:0:0) (time: 00:56.021)
        Info: no data from PAT after 6 seconds
        Info: no data from VCT(terr) after 26 seconds


Is it possible that this station is broadcasting in a way that isn't
compatible with the TV Wonder 600, or the related software that is using
it?   Or perhaps that the TV Wonder 600 just isn't good at receiving TV
on channel 23?


Thanks
-WD



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