Sony DVD recorder HXD870 - problems with freeview channels

Pixibelle

Standard Member
Can anyone help? I have just purchased this DVD recorder with inbuilt freeview. I have attached it to my sony Bravia TV (also with inbuilt freeview). I have connected them with an HDMI cable. When the DVD recorder is on I cannot pick up certain freeview channels BBC4/BBCi/BBC Parliament (all on one freeview multiplex). Everything is fine if I turn the DVD off. Not helpfull as i may want to record from BBC 4. This is also affecting my son's TV upstairs (on same aerial). Some research on the internet indicates the problem is the RF output channel used by the DVD recorder which clashes with the freeview multiplex channel. Is there anyway I can remedy this?

Thanks

Angela
 

Gavtech

Administrator
Can anyone help? I have just purchased this DVD recorder with inbuilt freeview. I have attached it to my sony Bravia TV (also with inbuilt freeview). I have connected them with an HDMI cable. When the DVD recorder is on I cannot pick up certain freeview channels BBC4/BBCi/BBC Parliament (all on one freeview multiplex). Everything is fine if I turn the DVD off. Not helpfull as i may want to record from BBC 4. This is also affecting my son's TV upstairs (on same aerial). Some research on the internet indicates the problem is the RF output channel used by the DVD recorder which clashes with the freeview multiplex channel. Is there anyway I can remedy this?

Thanks

Angela

Hello Angela. Welcome to the forum.

That would be a plausible explanation but..

The problem cannot be caused by the RF output channel - as this machine does not have a modulator ... and therefore does not produce an RF output - only RF pass through.

But this is an odd problem... Can you describe in careful detail [ including the route to your Son's TV ] the exact series of connection involved in your aerial system.
Also, I assume your TV has a signal strength gauge - Could you find out [ in conditions where you are able to receive it, ] what signal strength reading you get for BBC4.

I presume once the channel is blanked out you will not be able to get a reading at all - but if you can that would be instructive.
 

Pixibelle

Standard Member
Thanks for your response

We have connect this up as per Sonys own connectivity diagram for TV, video cassette recorder and DVD player/recorder. There is an RF cable from the aerial (rooftop) to "RF in" in the DVD recorder. There is a cable from "RF out" on the DVD to "RF in" on the VHS player, and there is a cable from "RF out" on the VHS to the RF socket on the TV. The actual TV is connected to the DVD by HDMI cable. There is also a scart cable connecting the VHS to line 1 on the DVD.

My sons TV is connected to the same aerial (with a device which allows two TV's to be connected to the same aerial). At the moment I have my DVD off and am happily watching BBC4, but my son can't? He has just told me he doesn't usually watch BBC4 anyway so can't tell me if he could ever get it!

I can't find a signal strenght guage on the tV, but have one on the DVD. Obviously as soon as I turn the DVD on BBC4 goes completely - no signal. But I have done a general signal check - it is confusing as it checks RF channel signals (doesn't tell you which channel) The results were:
channel 55 - Good 56%
Channel 56 53% fair
Channels 57 & 58 no signal
Channel 59 47% Good
Channels 60 & 61 No signal
Channel 62 39% poor
Channels 63 - 66 no signal
Channel 67 15% fair

I am not much of a techie - does this mean anything to you?

I also recently fitted a wireless router - could this affect the signal?

Thanks

Angela
 

JayCee

Distinguished Member
As an experiment remove the RF Out coax lead from the DVDR to the VCRs RF In (male plug end) and the RF Out lead from the VCR (female plug end) and connect both leads together.
With the VCR switched off...do you still have the problem?
 

ramjet

Banned
the video player will have an rf output and so this may be sending out an rf signal on a channel that is supposed to be freeview in your area

might be worth taking this out of the equation by removing the 2 coax leads and joining them together , and checking the freeview channels again

with the video recorder you need to set its output rf channels to an unused one for your area
 

Pixibelle

Standard Member
I tried taking the VCR out of the equation - it made no difference. Aldo we have always had the VCR and it has never affected freeview channels before. I wouldn't know how to set its output chanels to an unused one for our area, but as it caused no problems before, why should it now?
 

Gavtech

Administrator
Thanks for your response

We have connect this up as per Sonys own connectivity diagram for TV, video cassette recorder and DVD player/recorder. There is an RF cable from the aerial (rooftop) to "RF in" in the DVD recorder. There is a cable from "RF out" on the DVD to "RF in" on the VHS player, and there is a cable from "RF out" on the VHS to the RF socket on the TV. The actual TV is connected to the DVD by HDMI cable. There is also a scart cable connecting the VHS to line 1 on the DVD.

My sons TV is connected to the same aerial (with a device which allows two TV's to be connected to the same aerial). At the moment I have my DVD off and am happily watching BBC4, but my son can't? He has just told me he doesn't usually watch BBC4 anyway so can't tell me if he could ever get it!

Hi Angela.

Just one clarification please. The coax chain only seems to enter the DVDR once - so am I correct in assuming you are solely using the digital tuner part of the Sony DVDR?..
Since you mention the loss of only one multiplex, it seems safe to assume that you are correctly connected to the digital tuner... i.e. The RF sockets in the middle rear of the machine.

Also - just to eliminate one possible silly problem- Are you sure that the incoming aerial is connected to the input and not the output.
Likely it is OK as you specified that above.


Digital reception depends on the received signal being strong enough to cross the threshold of receivability. Once that threshold is crossed, reception is essentially perfect - so the quality and presence of a received signal is no indication of how close it runs to this threshold.

Basically, the DVDR should impose no loading on the signal, whether on or off... In an ideal world, the impact of the insertion of the machine and it's connecting cables into the RF chain should be zero... and it is tempting to say it may be faulty ... but I suspect it probably is not.

It isn't an ideal world of course, and the likeliest explanation is that there is just enough frequency sensitive attenuation in the whole system to just pull this particular multiplex below the threshold of receivability.

You have a number of flyleads in the chain and each connector and lead imposes significant loss at UHF frequencies.

It may help the analysis here to determine from which transmitter you are receiving. [ Do you know? You could do an online postcode checker which would probably provide that information - or send me your postcode by pm so I can check]
Usually in cases like this, the problem multiplex is being transmitted on one end or other of the local band... where the aerials sensitivity starts to fall off... and so it provides those muxes at a low strength to start with.
If I know the transmitter, I should be able to determine if this is an issue.

You also have a splitter in the feed - to feed your son's TV - and assuming it is a passive splitter, these impose a significant attenuation on the signal. [ If the splitter has a power supply then it is an active splitter and should not be imposing any loss ]
As it seems possible that your son's TV can never receive BBC4 - this is another strong indication that this particular channel / mux is right on the cusp of receivability.

So - what to do?

We can gather more information detail to determine which part of the band is involved.
BBC4 is on Mux B. You can see a list of all the channels that will be missing on Mux B here:http://www.dtg.org.uk/retailer/dtt_channels.html

Some testing: Is the splitter point accessible? Can it be temporarily taken out the chain to give you a direct feed as possible - and see if you then get BBC4 on the TV when the DVDR is on.
You could further improve this by making the UHF route to the TV as direct as possible... temporarily bypassing the VCR. This can be done by simply removing both sockets from the back of the VCR and plugging them together - but that leaves the flyleads in circuit and it would be better if their losses were removed also ... so take a direct feed from the DVDR to the TV.

Basically - all these tests will probably only lead to a conclusion that your signal strength is critically low on the problem mux.
That may be addressed by reducing the losses by using meaty low loss flyleads - but it would not address the loss of the mux at your Son's outlet.
All connectors should be in good condition and soldered if conventional coax. The aerial installation could be improved... or you could add a little amplification- assuming the splitter in use is passive only, that may be the ideal place to do it - Insert an active splitter to provide an active boost for both outlets.

Maybe if you are able to provide results of any tests such as bypassing the splitter if possible - or getting as direct a route to the TV as possible , via the DVDR we can see how to proceed. [ Transmitter info would be helpful too. ]

Regarding your wireless router - It should not interfere... but if you want to be certain, there will be an option somewhere in the software control to disable the transmitter. You could see if doing so would make any difference - but I think this is probably not a relevant issue.

Good luck.
 

Pixibelle

Standard Member
Thank you for taking so much time to address my problem. I will try all that you say - does look like a signal booster woud help, and I'll look into getting one.

I'll let you know how it goes.

Thaks again

Angela
 

mark_capewell69

Standard Member
Hi,

I have a HXD970 with the same problem. When the DVR is off I get all freeview channels no problem. When the DVR is turned on I lose all the programs on channel 55. My tv has a signal strength option and you instantly see channel 55 drop when the unit is turned on. It is only channel 55 that is effected all other freeview channels are fine.

I only have the Sony unit between my aerial and my tv so no other devices to interfere. I am only using the digital connection but have tried with the analogue pass through connected and it does the same.

I am at a loss as to why this is happening and think I need to contact Sony for a possible fix.

Anyones help would be appreciated

Mark
 

Gavtech

Administrator
Hi,

I have a HXD970 with the same problem. When the DVR is off I get all freeview channels no problem. When the DVR is turned on I lose all the programs on channel 55. My tv has a signal strength option and you instantly see channel 55 drop when the unit is turned on. It is only channel 55 that is effected all other freeview channels are fine.

I only have the Sony unit between my aerial and my tv so no other devices to interfere. I am only using the digital connection but have tried with the analogue pass through connected and it does the same.

I am at a loss as to why this is happening and think I need to contact Sony for a possible fix.

Anyones help would be appreciated

Mark

Welcome to the forum mark.

Your report is interesting.
You say all the other channels are fine... but you may simply mean that they stay above the reception threshold and you can still receive them.

Have you observed the TV strength meter for the other digital muxes - to see whether they drop also?... and is it by a similar amount?
Is channel 55 your lowest strength channel in the first place?

Also, does channel 55 happen to be at one end or other of the band of channels you receive... or in the middle somewhere?


It is probably worth contacting Sony to see what there reaction would be.
My guess is they would say contact your aerial contractor... but you never know.
 

HPSauce

Standard Member
Hi, I too have a similar combination of Sony Bravia and HXDR870 which suffers from the a very similar effect. I am on the Crystal Palace transmitter and have some slight break up of reception on certain channels, for example C4. Depending on the weather and time of day, when the 870 is switched on, reception sometimes becomes much worse on those marginal channels.

I think that the 870 is emitting a low level of RF intererence into the aerial connection when it is switched on but do not have the measuring equipment to prove this.

In fact all TV receiving equipment sufffer from these RF emissions to some degree but this would be must less likely to cause a noticeable effect with analogue reception.

A signal booster may well help to reduce the effect. Please let us know how you get on.

HPSauce
 

mark_capewell69

Standard Member
Thanks for the welcome Gavtech.

Only channel 55 drops and by a lot. On the TV strength meter it is 64% strength, 100% quality Channel 55 is not my weakest channel.

They had better not tell me to contact my aerial contractor as when I moved to freeview I paid £195 for a very large aerial on a very large pole :eek:)

It has to be a problem with the Sony unit due to it only effecting channel 55 and by so much.

I will locate an email address and send them the details to see what they have to say.

Mark
 

Gavtech

Administrator
Thanks for the welcome Gavtech.

Only channel 55 drops and by a lot. On the TV strength meter it is 64% strength, 100% quality Channel 55 is not my weakest channel.

They had better not tell me to contact my aerial contractor as when I moved to freeview I paid £195 for a very large aerial on a very large pole :eek:)

It has to be a problem with the Sony unit due to it only effecting channel 55 and by so much.

I will locate an email address and send them the details to see what they have to say.

Mark

Yes do. A notch response like this is definitely not right.

You'll keep us informed of course. - Thanks and Good luck.
 

Pixibelle

Standard Member
just to let you know I did bring up this problem with Sony and they said sometimes a dvd can interfere with reception especially if both have a freeview tuner. I thought this was a terrible response as I purposely bought two sony products which I thought should be compatible. More and more TVs are bring sold with integrated freeview, as are DVD players (especially Sony). I have since purchased Sky as I hoped it would boost my signal and solve my problems, but (see another thread http://www.avforums.com/forums/showthread.php?t=692367
) I now have problems with setting this up, and using Guide Plus!.

Angela
 

Gavtech

Administrator
just to let you know I did bring up this problem with Sony and they said sometimes a dvd can interfere with reception especially if both have a freeview tuner. I thought this was a terrible response as I purposely bought two sony products which I thought should be compatible. More and more TVs are bring sold with integrated freeview, as are DVD players (especially Sony). I have since purchased Sky as I hoped it would boost my signal and solve my problems, but (see another thread http://www.avforums.com/forums/showthread.php?t=692367
) I now have problems with setting this up, and using Guide Plus!.

Angela

Hello again Angela.

In a way I am sorry that you have given this up.
I regard this as a potentially very serious issue that requires a proper explanation or investigation by Sony.

Mark and HP sauces similar experiences above are certainly suggestive of a significant issue that needs looking at.

You would have had my support and backing ... and I am sure a number of others on this forum.
It is not adequate for them to say there can be reception interference between two products and leave it at that.
Even at the simplest of levels that will contravene regulatory practices.

At the very least they should provide a technical account of how, and why, this can be.


Regarding your Guide problem, there is plenty of good help in that regard already on the forum so I am sure you will be able to get that sorted out.
I've not been back to check your post... but the usual problem is simply that it can take a great deal of time for the guide to load... up to 3 days in extreme cases.
Good luck with it.

Thanks for reporting back.
 

Plutox

Standard Member
I regard this as a potentially very serious issue that requires a proper explanation or investigation by Sony.
Absolutely. I have an RDR-HXD970, also a Philips Freeview box which incorporates a signal level facility to ascertain the signal quality and quantity available on every channel. I have examined the signal at the Freeview box for each of the available multiplexes and can confirm that switching the recorder on or off made no difference whatsoever - I'd have been rather surprised if it had.

Like you, I feel that this requires further investigation. Sony Freeview tuners are unlikely to be all that different from any others - there aren't that many Freeview chip sets to choose from!

One reported instance may well indeed be a one-off incident. But two or three such reports must mean something and right now, it looks like a rather bizarre 'something'. If Sony really are aware of a subtle incompatibility (mutual interference) between its own units, that has the making of a very expensive liability in the style of an American class action.
 
M

mrfreeview

Guest
just to let you know I did bring up this problem with Sony and they said sometimes a dvd can interfere with reception especially if both have a freeview tuner. I thought this was a terrible response as I purposely bought two sony products which I thought should be compatible.

Yes I agree this is a terrible response from SONY and looking back at the fiasco with the complete range of HXD*70 machines deleting EPG timers when set via DVB-T seems typical of how SONY carry on these days.

With the HXD*70 timer issue it may be fair to say that the SONY help desk was less than "next to useless".

They simply refused to even acknowledge that there was a problem across the whole product range, despite months of bombardment from memebers of avforums.

And perhaps far worse also trying to blame anything and everything as the cause of the problem....simply IT COULDN'T POSSIBLY be in a SONY product!

The issue also exposed, for me, the lack of knowledge that the help desk actually possess on the products they claim to support.

And for this "quality service" they expect you to call a revenue share premium rate 0870 number! Fortunately there is an 0800 freephone equivalent...check www.saynoto0870.com

On a technical note your SONY products will have a CE marking. This means that they have passed an electromagnetic compatability test with respect to suseptability and emission. So to claim that they will interfere with each other appears to be nothing other than utter rubbish.

If anyone would care to PM me I may be able to provide a SONY contact.

Has anyone checked the power save option that they have set as per page 130 of the handbook?

Perhaps given that this is a clone of a Pionner machine the handbook may just be wrong!

When I owned a HXD1070 I had the DVB-T signal via an external splitter so I was not trying to connect devices in series. This could be a "solution" to your problems.

I hope my post has been of use :)
 
M

mrfreeview

Guest
I think that the 870 is emitting a low level of RF intererence into the aerial connection when it is switched on but do not have the measuring equipment to prove this.

Or there is a DC component present on the "Digital output" when the HXD-*70 is powered up OR an harmonic of 50Hz or similar from some switched mode power supply within the HXD

What is not clear is on the "Digial input" to the HXD how is the signal split between the internal DVB-T decoder chip and the "Digital Output".

Is this a passive splitter...I suspect not! But some "clever electronic device" that can/does behave a "bit strange" when powered up...perhaps due to component tolerance
 

mark_capewell69

Standard Member
Hi all,
last night I pulled out the tv and did some cable changes to test the tuner. Firstly I used a Y connection to give signal direct to the TV and direct to the DVD Recorder. TV was fine until DVD unit turned on then channel 55 effected again. So test 2 was to connect aerial direct to DVD with no aerial connection to the TV at all, then just use the HDMI to connect the DVD Recorder to the TV. Signal on DVD Recorder on channel 55 was non existent. All other RF channels are fine.

To me this does point to the digital tuner in the DVD Recorder being lets say "C"ompletely "R"ediculous "A"nd "P"athetic. ;)

I have not had any reply from Sony as yet but will be updating them with my findings.
 

Gavtech

Administrator
Hi all,
last night I pulled out the tv and did some cable changes to test the tuner. Firstly I used a Y connection to give signal direct to the TV and direct to the DVD Recorder. TV was fine until DVD unit turned on then channel 55 effected again. So test 2 was to connect aerial direct to DVD with no aerial connection to the TV at all, then just use the HDMI to connect the DVD Recorder to the TV. Signal on DVD Recorder on channel 55 was non existent. All other RF channels are fine.

To me this does point to the digital tuner in the DVD Recorder being lets say "C"ompletely "R"ediculous "A"nd "P"athetic. ;)

I have not had any reply from Sony as yet but will be updating them with my findings.

Hi Mark.

Again your report is interesting.
I am surprised to see that in your 'Y' configuration that the Sony tuner is apparently affecting something 'backwards' - Upstream - so to speak.
[ Angela's experience also seemed to indicate this was happening, although she could not be sure]

I don't suppose you happen to know if the Y splitter you are using is resistive or inductive?

Would you be prepared to do that test again? ... and confirm that the signal damping is being delivered by the coax [ and not other radiation] by disconnecting the cable coming from the Sony at the Y split... whilst it is in the condition of blanked out 55 on the TV ... and confirm that 55 returns to the TV.
 

mark_capewell69

Standard Member
Hi Gavtech,

yes I will do the test again tonight and post you the results. As for the Y connector it was a cheapie one that came in a kit so not sure on the type.

Mark
 

mark_capewell69

Standard Member
Hi Gavtech,

think I might be onto something. Having had a go at reinstalling the Y connector I managed to unplug the HDMI cable and channel 55 then sprang into life. Replaced the HDMI with a scart connection to the TV and I get the same signal strength on the TV as on the DVD Recorder.

I will get my hands on another HDMI cable to see if it is the cable or the HDMI output from the DVD.

I am aware of different versions of HDMI but not sure what version the existing cable is.

Will keep you informed

Mark
 

JayCee

Distinguished Member
This is weird...how can an HDMI output affect the tuner input on both TV and DVDR? :confused:
 

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