Picture/sound break up

Andybrody

Member
Hi all
Not posted for while all been running well for ages.
Recently for about a week I have been experiencing random picture and sound break up on HD channels only.
I'm tuned into Mendip transmitter I have done a complete re-tune on automatic tuning and then restored everything from a recent manual backup.
I thought this had cured the problem but after about 4/5 hrs the problem re-appeared but does not happen so frequently. Before re-tune it was happening ever two or three minutes and always at major scene change,
now it only happens at about 20 to 30 minute intervals.
I hope that the tuner is not packing up, I have tried before re-tune recording one HD channel and then watching another HD channel to try and force it to use the second tuner for current screen display but the problem persisted

I have included the following info.

Web interface version: 1.4.2-7
Custom firmware version: 3.00 (build 2137)
Humax Version: 1.02.32 (kernel HDR_CFW_3.00)
Loader Version: a7.30
System ID: 80bc.7e00
Serial Number: 63 7104460 01483
Last Boot Reason: Remote control handset

upload_2017-10-21_21-17-27.png

Thanks for looking hope someone may be able to help
Cheers
Andy
 
OP
Andybrody

Andybrody

Member
Ok here's my update with a twist.
I have reduced signal strength by moving the feed from full output on loft amp to one of the normal (lower)
outputs. I'm not sure of the gain difference but it has not change the signal level or quality (as above).
The good news is that I have not had any picture/sound breakup at all, here's the twist before reducing the signal strength I used to have to wait for "PROCESSING" for ages uptown 20 seconds when trying too look at recordings on the hard drive either locally or on bedroom HD Fox T2, I had learnt to live with that as I believed the HDD needed formatting or replacing.

So thanks prpr for the suggestion that has cured two problems
 
OP
Andybrody

Andybrody

Member
Your signal's too strong. Get an attenuator (or take your amplifier out).

Ok here's my update with a twist.
I have reduced signal strength by moving the feed from full output on loft amp to one of the normal (lower)
outputs. I'm not sure of the gain difference but it has not change the signal level or quality (as above).
The good news is that I have not had any picture/sound breakup at all, here's the twist before reducing the signal strength I used to have to wait for "PROCESSING" for ages uptown 20 seconds when trying too look at recordings on the hard drive either locally or on bedroom HD Fox T2, I had learnt to live with that as I believed the HDD needed formatting or replacing.

So thanks prpr for the suggestion that has cured two problems.
 

prpr

Well-Known Member
I'm not sure of the gain difference but it has not change the signal level or quality (as above).
Where are you looking? If the WebIf, then it won't unless you retune. It will most certainly have dropped the level - I would guess at least 15dB (but we don't really know how that affects what the Humax software displays).
Do you know what make/model your loft amp. is? Sounds like something that ought to be part of a bigger distribution system, rather than the normal run-of-the-mill domestic stuff.
 

Black Hole

May contain traces of nut
I'm not sure of the gain difference but it has not change the signal level or quality (as above).
Please be aware that the signal stats reported in WebIF >> Diagnostics >> Mux Info (as per your screenshot above) are snapshot figures accumulated by the tuning process, at the time of tuning. If you perform an auto-tune you get stats for all the muxes, whereas if you do a manual tune there are only stats for the mux you tuned last.

The only way to get proper live signal condition figures is Menu >> Settings >> System >> Signal Detection, then select each mux in turn and watch the strength and quality bars for half a minute or so looking for quality dropping below 100%.
 

Luke

Well-Knwοn Мember
If you perform an auto-tune you get stats for all the muxes, whereas if you do a manual tune there are only stats for the mux you tuned last.
After starting an auto tune and cancelling it so that no channels are stored one of my HDR-FOX T2s it was then tuned via the manual tune menu and the web-if showed this:
After retune.PNG

Then after reboots it changed to this:
After reboot.PNG
The last 3 tunes were all manual but the strength and quality now show stats for all muxes.
 

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prpr

Well-Known Member
Tunefix overwrites zero signal readings in the database with those it cached on the previous reboot. To get accurate figures you should do an auto-tune followed by a reboot to update the cache. Then any subsequent manual tunes which would zero everything apart from the mux. you're tuning will get updated correctly on the next boot.
 

Luke

Well-Knwοn Мember
Tunefix overwrites zero signal readings in the database with those it cached on the previous reboot. To get accurate figures you should do an auto-tune followed by a reboot to update the cache. Then any subsequent manual tunes which would zero everything apart from the mux. you're tuning will get updated correctly on the next boot.
I've done that and of course you correct concerning the 2 muxes from my example not being repoplated. I just have the other muxes populated from the manual retune.
I.e. after wiping out the channels, fully rebooting and then retuning I have all but two of the muxes populated which is correct for how I retune to Crystal Palace (London), and after another reboot the situation now stays the same with all but two muxes populated. Sudbury is a bit different and for that I would end up with just the 1 mux populated as Black Hole presumed.
if you do a manual tune there are only stats for the mux you tuned last.
It depends which transmitter you tune to and how you manually tune. With Crystal Palace the quickest why for me to tune in my location after a total channel wipe it can end up with all but two muxes with stats.
 
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Black Hole

May contain traces of nut
I was not accounting for having tunefix installed. Without that, it would behave as I stated.

Even with tunefix, the figures are only snapshots and cannot account for dynamic conditions. The only way to be sure is by the process I described.
 
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Luke

Well-Knwοn Мember
I was not accounting for having tunefix installed. Without that, it would behave as I stated.
My previous description included enough detail to show that tunefix had not impacted what was shown in the first image.
My first image was before tunefix has been unable to do anything. The machine had not been rebooted after the manual tuning yet.

Also it was just the 8th and 9th mux in the second image which were.

Without tunefix my first image still applies and demonstrates that using the manual tuning menu can result in stats for more than 1 mux.

Even after destroying the cache as prpr stated and then using identical manual tuning it results in the same selection of manual tuning as when the cache had not been destroyed and there had been no reboot yet.
It is repeatable.
After deleting all channels via a cancelled auto-tune and then a full reboot:
Starting position after reboot.PNG
Then immediately using Manual Search menu and immediately taking a screen shot:
After manual tuning.PNG
 

prpr

Well-Known Member
using the manual tuning menu can result in stats for more than 1 mux.
How exactly are you doing this then (because I've only ever seen the numbers for the last mux. manually tuned, and everything else being zero)?
 
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