Poor reception after recent channel updates

cal60

We are in Monaghan town and until recently had good reception. Both tv's are tuned as country uk , region NI as I have found reception on RTE especially is better this way. We were getting messages about the need to retune on 4th Sep as there were changes to frequencies being made. Since retuning Channel 4+1 HD has gone altogether and Channel 4 HD and RTE 1 HD are both suffering breakup.

Anybody else having these issues ?

Elvis Hammond

Ch.4 +1 HD is now on a frequency that's more than likely incompatible with your aerial setup.

The others should be alright: can you find which UHF channel no. or frequency you're getting them on?

The Cush

For the Saorview channels check your recommended transmitter here - http://coverage.2rn.ie/index700.php

danm14

The multiplex which carries Channel 4+1 HD is now being broadcast on UHF Channel 51. It's broadcast at quite a low power (I'm surprised it was ever receiveable in Monaghan at all) so the very strong signal from Clermont Carn (Dundalk) on UHF Channel 52 might be interfering with it.

Are you able to receive Forces TV on 96? If you have it, your aerial should be fine for the new frequencies, and Channel 4+1 HD should return in March when transmissions on Channel 52 from Dundalk cease.

cal60

@ Elvis Hammond .Thanks for the reply.
RTE 1 HD seems to be coming in on Ch43 DVB-T

The Cush

cal60 wrote: »

Thanks for the reply.
RTE 1 HD seems to be coming in on Ch43 DVB-T

Monaghan transmitter, UHF 40 & 43.

How may aerials do you have?

cal60

2 aerials. Had to get a new aerial a couple of years ago to get the Saorview channels.

Elvis Hammond

cal60 wrote: »

... RTE 1 HD seems to be coming in on Ch43 DVB-T

That's the Monaghan transmitter, but it's possible your aerial is pointed at Clermont Carn (Dundalk direction). Do you have any duplicates of the Saorview channels?

The Cush

I'm assuming as he has installed the TVs with UK as the country, all Saorview channels are stored in the 800s including duplicates.

cal60

Yes the Saorview channels are in the 800's. If it helps anything the signal strength on RTE1 is S94% Q52%. From looking at the Aerial it seems to be pointed at Corcaghan which is where the RTE mast is.

The Cush

cal60 wrote: »

If it helps anything the signal strength on RTE1 is S94% Q52%. From looking at the Aerial it seems to be pointed at Corcaghan which is where the RTE mast is.

The SQ is low for some reason, can you check the SQ for all the channels in the 800s. Those on the old frequencies will have a dot after the channel name. Is the SQ the same for the new frequency channels and the old frequency channels?

I'm wondering if the aerial is "out of group" for the new channels? The aerials here have a coloured tip to identify their group, can you tell what group your aerial is?

Digifriendly

I have been informed on this and another forum that certain diplexers (combining 2 areials into 1 for RTE/BBC) are cutting out Com 7 (BBC News HD, Ch. 4 HD +1) which is now on C51 and Com 8 (Freesports) which is now on C60. As I understand it C51 is difficult to receive for this reason and not the fact that RTE is still using C52 but will know next March for sure so I'm going to hold off getting any aerial work done. Interesting that when I turn the power for the amplifier for RTE reception off C51 comes in so poster above may be right that C52 is interfering.

cal60

image.jpeg

Image of aerial

Rick_

cal60 wrote: »

Since retuning Channel 4+1 HD has gone altogether and Channel 4 HD and RTE 1 HD are both suffering breakup.

Anybody else having these issues ?

Channel 4 HD is on the same MUX as BBC 1 HD, BBC 2 HD, UTV HD and Channel 5 HD, are these all working OK?

The Cush

cal60 wrote: »

image.jpeg

Image of aerial

I assume the top aerial is a high-gain (Group A?) aerial for Divis and the lower one a wideband LP for Monaghan.

Could that be a 5052 or a 3740 UHF Diplexer below with Monaghan on the high leg and if so could this be affecting reception of the new Saorview frequencies from there?

mrdtv2010

I think there are several reasons for a lot of these problems following the NI miniswitchover:

a) Incorrect diplexers now being used

b) Signal overload between adjacent channel configurations (eg Clermont Carn and Kilkeel).

In case a) new diplexers may be needed and replacement may need to wait until the final Saorview switchover.

In case b) variable attenuators may or may not work when applied to the more powerful signal. Digifriendly's post was telling in that respect, when the amp was removed the lower powered adjacent channel worked. This is because the systems have specific ACI rejection properties and the receivers are built to minimum standards. This is very reminiscent of early DTT when some of the receivers did not work because adjacent high power analogue signals drowned out the lower power DTT signal: inserting variable attenuators restored the service.

I suspect trial and error may be necessary but a good start would be to know what the diplexer cut point is and dial back on amplification. I am afraid that the 700Mhz clearance will probably lead to more Freesat installations as overlap coverage is likely to be clipped.

TAFKAlawhec

Digifriendly wrote: »

I have been informed on this and another forum that certain diplexers (combining 2 areials into 1 for RTE/BBC) are cutting out Com 7 (BBC News HD, Ch. 4 HD +1) which is now on C51 and Com 8 (Freesports) which is now on C60. As I understand it C51 is difficult to receive for this reason and not the fact that RTE is still using C52 but will know next March for sure so I'm going to hold off getting any aerial work done. Interesting that when I turn the power for the amplifier for RTE reception off C51 comes in so poster above may be right that C52 is interfering.

When E52 & E56 is switched off at Clermont Cairn (due to be on 4th March 2020), COM7 & COM8 at Divis is due to move to channels E55 & E56 on the same day, in common with the phased UK SFN for those two multiplexes when each region is having other multiplexes being cleared off frequencies above E48. The present transmissions from Divis on E51 & E60 are only temporary.

Elvis Hammond

Digifriendly wrote: »

... Interesting that when I turn the power for the amplifier for RTE reception off C51 comes in so poster above may be right that C52 is interfering.

Not in this case.

mrdtv2010 wrote: »

... In case b) variable attenuators may or may not work when applied to the more powerful signal.

That can't be done with CC/Kilkeel, as those installs use a single aerial.

cal60

PFMC84 wrote: »

Channel 4 HD is on the same MUX as BBC 1 HD, BBC 2 HD, UTV HD and Channel 5 HD, are these all working OK?

All the HD channels above are coming in on CH24. The signal stats today are S~90% Q~65-70%.

RTE1 on CH43 S92% Q25-40% and unwatchable.
Above are all on. Walker WPS3219SM TV with built in tuner

Second TV tuner:
On a Panasonic DMR-HWT130 tuner box connected to a Phillips TV
RTE1 on CH43 S and Q both approaching 100% and good reception
HD channels above CH24 .S~90% Q~20% but no difficulty watching.

Perhaps the Walker tuner is just not as efficient as the Panasonic ?

Elvis Hammond

Unless you're behind a hill or trees or some other obstruction, you shouldn't really be struggling for signal.

Was there any other work done when the aerial was changed, say to interior cables etc.? The problem is probably downstream of the stuff on the roof.

The Cush

cal60 wrote: »

RTE1 on CH43 S92% Q25-40% and unwatchable.
Above are all on. Walker WPS3219SM TV with built in tuner

Second TV tuner:
On a Panasonic DMR-HWT130 tuner box connected to a Phillips TV
RTE1 on CH43 S and Q both approaching 100% and good reception
HD channels above CH24 .S~90% Q~20% but no difficulty watching.

Perhaps the Walker tuner is just not as efficient as the Panasonic ?

Tuners vary as to how they work with weaker signals, we have seen this since Saorview started.

As the last poster, EH says, the problem you have with the Saorview frequencies is somewhere between the aerial and TV points as indicated by the near 100% signal at the second TV and at lower quality signal at the other TV point.

This could be faulty cable due to physical damage, water ingress etc,. Faulty connections etc.

How is the incoming split between the 2 or more TV points?
Is there a distribution amp to split and feed the TV points?
Is there a masthead amplifier out near the aerials?

cal60

@ the Cush . The aerial is split on a powered unit in the attic . Not sure about a masthead amplifier.

I tried tightening up the end of the cable at the distribution unit and TV end as well keeping mains cable and aerial cable separated and the position seems improved somewhat eg CBS is coming in on CH30 which was previously lost. On the other hand atmospheric conditions are better tonight .

I'll see how it goes for a couple of days.

Elvis Hammond

The only time atmospheric conditions should come into it, is the odd occasions when high pressure can cause distant transmitters to come in strong enough to cause interference.

This could actually be the case in the next few days.

cal60

Elvis Hammond wrote: »

The only time atmospheric conditions should come into it, is the odd occasions when high pressure can cause distant transmitters to come in strong enough to cause interference.

This could actually be the case in the next few days.

There may be some other explanation but our experience (even prior to the retune) is that when it rains in particular that the RTE reception could be poor.

Elvis Hammond

Is the aerial looking through trees? The install should really be delivering sufficient extra margin to cope with a bit of rain.

Digifriendly

Com 7 (C51) now coming through clear on one of my TVs with excellent signal quality. Is it HP weather causing this? Since Frequency change channels on COM 7 have been unwatchable.

cal60

Digifriendly wrote: »

Com 7 (C51) now coming through clear on one of my TVs with excellent signal quality. Is it HP weather causing this? Ssince Frequency change channels on COM 7 have been unwatchable.

Ive just tried a manual tune on Ch51 and nothing coming in there but I too feel weather can have an impact .

Digifriendly

cal60 wrote: »

Ive just tried a manual tune on Ch51 and nothing coming in there but I too feel weather can have an impact .

I have to add it is only on one TV and not the other but signal quality has shot up dramatically.

Elvis Hammond

cal60 wrote: »

Ive just tried a manual tune on Ch51 and nothing coming in there but I too feel weather can have an impact .

I mentioned in post #2 that your aerial setup would be incompatible with the new COM 7 & 8 frequencies: the Divis aerial itself is more than likely a grouped type, & will be worse than useless on chs. in the 50s & 60s, & the diplexer would filter them out anyway. You're too far away from Divis for sufficient signal to be picked up on the other aerial, or leak in by other means.

Weather shouldn't have any noticeable effect, unless maybe due to something like trees getting wet.

TAFKAlawhec

Elvis Hammond wrote: »

Weather shouldn't have any noticeable effect, unless maybe due to something like trees getting wet.

In the days in the UK where low-powered DTT sat alongside analogue transmissions, it wasn't unusual to hear of a few people mention that reception of some multiplexes were affected by weather conditions at the time or that had just been passed. A multiplex could be gained or lost in wet weather, for example a rainy cloudy day could slightly increase the general reception quality due to "rain fade" marginally attenuation a distant co-channel analogue signal. Equally, a multiplex or two might have gone down if the aerial was in the attic, pointing through tiles, and the tile material had a habit of holding on to the moisture. With DSO taking place by region in the UK and high power multiplexes taking its place, this is rarely heard about any more.



Rain fade in these parts is normally associated with Ku and Ka band satellite reception, but in some other parts of the world it can affect reception of UHF & even VHF terrestrial signals. However given that Ireland has a temperate maritime climate where humidity is most often medium to high even in sheltered inland areas well away from the sea throughout the year, and that it very rarely suffers from mother nature's extremities that other landmasses get occasionally afflicted with, seeing rain fade affect such reception tends to be a very rare occurance - but I have seen it happen once back in September 2012 before the analogue TV network was shut down - a heavy rain shower lasting about 3-4 minutes succeeded in wiping out UHF reception from Carin Hill which only recovered around two minutes after the rain stopped. I suspect that as the RX site was a significant distance from Cairn Hill and not LOS, the falling of torrential rain on the peak of a boggy mountain a few miles away in line with the signal path caused diffused signals that can otherwise allow for knife-edge reception to be absorbed instead.

Digifriendly

Interesting that over the last few days Com 7 (C51) has been coming through in one of my TV sets. Even more interesting is that when I now power up the masthead amp (for CC reception only) the signal quality for C51 improves substantially whereas last week I had to turn the power from the amp off to get any signal for C51. Does this suggest that Com 7 is coming through my RTE aerial rather than one for Divis?
BTW I live in Moira and am c12 miles as crow flies from Divis and have always had good reception from CC. My aerial for Divis (televes Pro 27) is wideband and was installed back in 2002 in order to get the old Freeview multiplex that was on C48. I think that my RTE aerial (Triax 52 element) is possibly wideband as well and both aerials are diplexed.