[mythtv-users] Signal strength now reporting 50% instead of 100%

[James Abernathy]

On Mon, May 9, 2022 at 7:41 AM Paul Harrison <mythtv at mythqml.net> wrote:

> On 09/05/2022 11:41, James Abernathy wrote:
>
>
>
> On Sun, May 8, 2022 at 8:39 AM James Abernathy <jfabernathy at gmail.com>
> wrote:
>
>>
>> Results of my first test of the Hauppauge WinTV Quad HD in a new system
>> with Ubuntu 20.04.3 LTS and mythtv v31.
>>
>> I installed Ubuntu 20.04.3 minimal and added the apt repository for v31.
>> The install was as expected and I setup the 4 tuners to correspond to the
>> Quad tuner PCIe card.
>>
>> I used a table top antenna in my lab since I didn't have a tap for the
>> big attic antenna.  I could not get the PBS station 40 miles away as
>> expected but the nearby stations all scanned.  While watching LiveTV, I
>> noticed that the signal strength displayed was 80-100% instead of 40-50% in
>> V32 Ubuntu 22.04, my production backend.
>>
>> I'll try later today or tomorrow to move the test PC to a room that can
>> access the same 8-way splitter that all my other tuners and tvs are
>> connected to.  At this point it's looking like the difference between v31
>> and v32 or Ubuntu 20.04 and 22.04.
>>
>> Where I'm located with respect to the TV towers you can get great signals
>> with a coat hanger jammed into the F-connector.
>>
>> Jim A
>>
>
> I've narrowed down when the signal reporting gets changed. On my newly
> built test system with MythTV v31 on Ubuntu 20.04.3 LTS my signals were
> reported as ~100% on most of my channels using my Hauppauge WinTV quadTV as
> it had for years on my production backend.
>
> I added the ppa:mythbuntu/32 repository and upgraded to v32. The system
> updated all 21 packages and everything was working as before but now on v32.
>
> But when I use Watch Live TV all my reported signal strengths were between
> 40-50%.  So the change is MythTV v32 related and not the version of Ubuntu.
> The OS remained at Ubuntu 20.04 with latest patches without any package
> updates to Linux during this test.
>
> Jim A
>
>
> Could be this commit which changed the signal strength range for DVBv5 :-
>
> https://github.com/MythTV/mythtv/commit/5d76841b8c1878
>
>
> You could  try starting the backend with --dvbv3 to see what you get with
> the old DVB v3 API.
>
>
> Like other have said if it not causing you any problems then I wouldn't
> worry to much about it.
>
>
> Paul H.
>
You are correct. Starting the mythtv-backend with --dvbv3 does restore the
signal strength to what I was seeing on v31.

So what I'm hearing is by default in v32 the signal strength is based on
dbm instead of %. Are there any problems using --dvbv3 instead of the
default??

Jim A
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