From: Vincent McIntyre <vincent.mcintyre@gmail.com>
To: Eyal Lebedinsky <eyal@eyal.emu.id.au>
Cc: list linux-media <linux-media@vger.kernel.org>
Subject: Re: [progress]: dvb_usb_rtl28xxu not tuning "Leadtek Winfast DTV2000 DS PLUS TV"
Date: Tue, 26 Sep 2017 22:45:11 +1000 [thread overview]
Message-ID: <20170926124508.GA17883@ubuntu.windy> (raw)
In-Reply-To: <678bf4fa-5849-1fb2-adf1-a07458767d9e@eyal.emu.id.au>
On Tue, Sep 26, 2017 at 02:32:26PM +1000, Eyal Lebedinsky wrote:
>
> While the problem persists, I managed to find a way around it for now.
>
> I changed the antenna input.
>
> Originally I used a powered splitter to feed all the tuners, and it worked
> well with the out-of-kernel driver. This driver does not build or work with
> a more modern kernel so I shifted to using dvb_usb_rtl28xxu which fails to
> tune.
>
> The new wiring splits (passive) the antenna in two, feeds one side directly
> to the two "Leadtek Winfast DTV2000 DS PLUS TV" cards (through another passive
> 2-way) and the other side goes to the old powered splitter that feeds a few
> USB tuners.
>
> Now all tuners are happy. It seems that the "Leadtek Winfast DTV2000 DS PLUS TV"
> cannot handle the amplified input while the USB tuners require it.
>
> I hope that there is a way to set a profile in dvb_usb_rtl28xxu to attenuate
> the input to an acceptable level thus unravelling the antenna cables rat-nest.
Glad you had some success.
I did some more rummaging in v4l-utils. It may help you to know about
dvb-fe-tool, which gives information about the frontend device
(eg /dev/dvb/adapter0/frontend0). In particular you can monitor the
s/n as you make changes:
# dvb-fe-tool --femon -a 0 #here doing adapter0/frontend0
It displays info about the signal quality and the carrier/noise (C/N) ratio,
which might help any investigation of where the driver fails to cope as
you change what you are feeding it.
I noticed your dvbv5-scan showed C/N around 20dB but the manpage shows
'good signal' with C/N of 36dB which suggests the device should be
expected to deal with higher signal levels.
Once you figured out the signal level, did a dvbv5-scan work with no
errors? In the example you showed I saw the channels getting 'lock'
but then some kind of error occurred.
Regards
Vince
next prev parent reply other threads:[~2017-09-26 12:45 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-18 4:26 Urgent: dvb_usb_rtl28xxu not tuning "Leadtek Winfast DTV2000 DS PLUS TV" Eyal Lebedinsky
2017-09-23 12:48 ` f26: " Eyal Lebedinsky
2017-09-24 9:04 ` Vincent McIntyre
2017-09-24 9:42 ` Eyal Lebedinsky
2017-09-25 0:16 ` Eyal Lebedinsky
2017-09-25 13:24 ` Vincent McIntyre
2017-09-25 14:37 ` Eyal Lebedinsky
2017-09-25 15:23 ` Eyal Lebedinsky
2017-09-26 4:30 ` Eyal Lebedinsky
2017-09-26 4:32 ` [progress]: " Eyal Lebedinsky
2017-09-26 12:13 ` Eyal Lebedinsky
2017-09-26 12:45 ` Vincent McIntyre [this message]
2017-09-26 13:17 ` Eyal Lebedinsky
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20170926124508.GA17883@ubuntu.windy \
--to=vincent.mcintyre@gmail.com \
--cc=eyal@eyal.emu.id.au \
--cc=linux-media@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.