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Recent HD Upgrade

boon147

Active Member
Morning all,

I recently upgraded to a Digital Stream HD PVR (Having also tried the SAGEMCOM first) and i noticed that they needed a lot stonger signal.

I fully expected this, and all seemed ok, but i did the 'fan' fix last night on my DS, and when i came down this morning, i couldnt get any signal? In order to rectify this, all i had to do was move the excess cable at the back of the box, but it would only work if the cable was left in a certain place?

I assume this is due to interferance, but i have a 90db sheilded cable. Anyone have any idea's? I dont have a booster in the loft, and would like to avoid that option if possible.

Cheers,

Paul
 

Rodders53

Distinguished Member
Which lead(s) needed to be moved? What cable is "90dB shielded" and where is that figure published?

Try different hdmi leads as - the expensive ones especially - seem to leak UHF which is picked up by aerial cables. Pound store ones have regularly been reported here to be better screened and solved problems for others.

It's good practice to keep cables as short as practically possible and to route aerial leads as far from all others as possible.

Is the downlead from the aerial in one continuous run? Is it double screen satellite grade (WF100 or equivalent) or something else?

If there's a wall plate is that a 'screened' or 'unscreened' variety?

Lastly is the aerial in the loft space or outside on the roof? What style of aerial is it?

You may find issues with your PVR are more frequently discussed in the PVRs and VCRs | AVForums.com - UK Online area? Have a read there in case a similar problem has occurred before - but don't double post (forum rules). A moderator will move the thread across if you ask.
 

boon147

Active Member
Thanks for the extensive reply.

Its my aerial lead that needs to be moved, and its the aerial that is apparently 90db sheilded. It isnt printed on the cable, but it was stated in the advert when i bought it. The only markings on the cable are 75 Ohm.

The HDMI leads i have are not expensive, however i have a few spares so i will swap them to see if it makes a difference.

I did think about drilling a hole in my entertainment unit at the back of my PVR, so i can route the aerial cable down and underneath the unit (unit is raised off the floor so cable wont be trapped) and into the wall plate. Unfortunately the wall plate is about 8 metres away from the PVR.

The down lead is in one continuous run, however im not sure what grade it is as it is a new house and was installed before i moved in, and again as for the wall plate, im not sure.

The areial is loft mounted, and is a High Gain aerial.

The issue is not with the PVR, because the SAGEMCOM i had before behaved the same way. The only thing that is different since i had my SD PVR is that fact that the signal is now transferred via HDMI, so maybe you are onto something there.

Ill change the HDMI lead, and also route the cable under the unit so its away from all cables.

Ill give it a go and post back with the results.
 

Rodders53

Distinguished Member
I've just had a look at the specs of some decent quality aerial cables and >85dB and >90 dB figures for 'screening' is typical. If that is used for the fly lead and is 8m from the wall socket then your idea careful placement is sound. {Anything local won't readily get into the down-lead or wall-plate connections.}

You should be able to gauge your downlead quality by looking at its construction (e.g. at the aerial is connection or behind the wallplate) and comparing it to Satellite, Television, FM, DAB, Aerial, Coaxial Cable, Plugs, Sockets, Connectors & Leads

If you have already gone through Digital Switchover you may need to reconsider that amplifier - if you don't want to fit the aerial outside. (If you haven't the power increase should help at DSO).
 

boon147

Active Member
Hi,

Thanks for your reply. I checked all plugs again and re-fitted any that looked faulty. Unfortunately the signal was still weak.

In the future, I will look at getting a really good aerial lead, as there are no markings on the cable so i have no way of knowing if it is correctly screened.

I think its down to a loft mounted aerial, coupled with a new PVR that is more sensitive and needs a good signal due to the HD (And yes the DSO has already happened in my area)

Anyway, after re-fitting the amplifier / booster in the loft, all is now working OK and the picture is spot on.

I will use this as a short term solution until i have the time to find out why this is happening.

Many thanks for your great help and advie. I will be back in the near future to nip this one in the bud.

Thanks again, i owe you a pint!
 

Rodders53

Distinguished Member
Loss #1: Aerials in lofts can lose a lot of signal compared to one outside. A reduction of 10dB (1/10th of the signal) is quite likely.

Loss #2: Loft aerials are lower than one outside above the roof and signals increase with height, usually

There's nothing wrong with using an amplifier. It's a normal requirement in some locations... even with outside aerials (masthead amplifiers).

Changing the aerial cable is unlikely to make a big difference to the signal delivered down it with the same aerial arrangement - in fact, it may not even be measurable. Double screened cable will reduce interference pick-up relative to a cheap cable but that doesn't seem to be your problem. Only getting the aerial outside will increase the signal picked up by the aerial you have.
 

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