Problem receiving AT THE RACES

Randyleprechaun

Hi,

Client of mine is having trouble with AT THE RACES channel.

Checked dish and aligned as best as could. Signal strength was about 60% quality a little over 50%.

Changed the LNB and now both signal strength and quality are nearly 100%.

The problem still persists. Channel breaking up and then signal goes completely.

All other channels appear to be fine, all though I haven't gone through them all.

I'm thinking about replacing the cable as it's easy enough, only about 5-6 metre.

Could the problem be with the box or card, or has anyone seen similar problems etc.

JDxtra

As a test, see if he has same issue with 'CBS Drama'. It's on the same sat transponder.

STB

Randyleprechaun wrote: »

Hi,

Client of mine is having trouble with AT THE RACES channel.

Checked dish and aligned as best as could. Signal strength was about 60% quality a little over 50%.

Changed the LNB and now both signal strength and quality are nearly 100%.

The problem still persists. Channel breaking up and then signal goes completely.

All other channels appear to be fine, all though I haven't gone through them all.

I'm thinking about replacing the cable as it's easy enough, only about 5-6 metre.

Could the problem be with the box or card, or has anyone seen similar problems etc.

Its on 2 weak transponders alright. 11304 (Ireland) and 11603 (UK). Here in hurricane land there is about a 30% drop over other Eutelsat TPs.

Having said that even allowing for the margin til breakup and given the percentages after replacing the LNB, I would be looking for the DECT phone that he has nearby.

Randyleprechaun

Right,

Went back to customer and brought my own sky box from home. Same problems with "at the races" and also "CBS Drama" and "CBS Reality".

I then ran anew cable out the window to the dish and still problem persists.

There is a cordless phone in the house but it is in the next room to the sat. receiver so I think that shouldn't be causing any problem.

The dish face is ever so slightly rusted but as I'm getting near 100% strength and quality I'm assuming the dish can't be the problem.(I've seen dishes before that are nearly rusted away working fine!!!!) I'm open to correction on this!!!!

Ronnie Raygun

Won't the 100% reading be for the default transponder the Sky box uses for signal readings, not what you had it tuned to? Can't you check/change the default in the service menu?

11344 mhz, when downconverted by the lnb, should be well away from the DECT frequencies. 11603 would be pretty close.

Not to say it isn't worthwhile to try switching the phone (or any other likely interferer) off.

Randyleprechaun

Ya, I tried unplugging the phone earlier and it didn't fix the problem!!!!

I'll change the default tp tomorrow and see what the signal levels are like. Just tried out on my own box at home and signal levels are identical same as the default tp

Antenna

Is the UK ATR viewable with an Irish ATR subscription if you tune it in in "other channels" ?? (only difference is the ads)

The UK one is on a different transponder and might be unaffected by your problem.

swoofer

came across this a few times but difficult to pin down, is the house a semi detached? does the cable go through cavities? are you using a wall plate to connect to sky box?
did you try fine tuning the lnb, it only takes a minute amount of adjusting? and use the best possible cable with no kinks or joins. i would even run a cable straight from dish to box.

Ronnie Raygun

What "fine tuning" can you do with a Sky lnb? They're all pretty much locked in place at whatever no. skew setting you use. No finer skew, or in/out movement.

STB

Ronnie Raygun wrote: »

What "fine tuning" can you do with a Sky lnb? They're all pretty much locked in place at whatever no. skew setting you use. No finer skew, or in/out movement.

Skewing a Sky LNB can have positive results, but the skew is limited.

Assuming that the dish is set up correctly. ie aligned and tweaked to maximise reception of the weak signals that prevail on Eutelsat 28.5, I would still maintain that the source of interference is one of 3 things, RF from a phone or other device coupled with poor cabling/joined cabling.

This taking into account that the OP has already eliminated a dodgy LNB/poor sensitivity in the tuner.

Ronnie Raygun

The stepped skew adjustment on a Sky lnb doesn't exactly qualify as fine tuning. That's what I was trying to say.

steveon

Have had the same problem in Limerick county, changed dish, ran new cables, removed wireless phones, baby monitors wireless printed, also upgraded customer to Sky hd box from std box nothing worked, tuning in the English version in the other channels worked but unfortunately cant record, checked customers 2 neighbours within a half mile and found them to both have the same problem, driving around the general area I found a home with a large amount of different masts aerials, and sat dishes all pointed towards the op's home which could point to the problem??? if not the fact as already pointed out it could be broadcasted on a weak transponders which is unacceptable seeing as it is quite a popular channel.. in Ireland at least.

Randyleprechaun

Already tried new cable, my own box (with at the races subscription), plugged out cordless phone......nothing worked.

Replacing dish at the minute.

Report later!!!!

Peter Rhea

Ronnie Raygun wrote: »

11344 mhz, when downconverted by the lnb, should be well away from the DECT frequencies.

1594 mHz would be in the satnav. (GPS etc.) frequency range. All nearby freqs. are also navigation: http://www.comreg.ie/_fileupload/publications/ComReg0890R3.pdf

Randyleprechaun

First of all, thanks to all who replied to thread...much appreciated.

Right,

Went there this morn and replaced the dish. At the races IRE worked for about 3 minutes, then gone. Spent an eternity tweaking the lnb but to no avail.

So, to recap,

1. The box and card are fine, as I tried my own box there and still had problem
2. The cable is fine, as I ran a cable out the window direct to dish and still had problem.
3. Replaced dish and lnb, signal levels are near 100%. Still no AT THE RACES, CBS Reality or CBS Drama.
4. Plugged out DECt phone and broadband....still no good.

So, I tuned in the UK version and customer is happy enough as they don't need the CBS ones.

Anyway, to add to the mix....and I know you'll think, why didn't he mention this before, but as glaringly obvious as it is...i didn't take much notice of it!!!!

There is a telecom tower directly in line of the dish. It's about 500 or 600 metres away. I know it's not blocking signal or anything but could there be issues regarding signals coming from the tower interfering with the sat signal for this weak transponder.

Thanks again all

Ronnie Raygun

I'd doubt the phone mast would be doing you any favours. Can you re-site the dish, even just for trial purposes?

Randyleprechaun

Ronnie Raygun wrote: »

I'd doubt the phone mast would be doing you any favours. Can you re-site the dish, even just for trial purposes?

The way the house is faced in relation to the tower means that I cannot re-site, well at least not any meaningful distance. Suppose I could do it as a trial anyway!!!

It's not just a phone mast either, it's an actual tower with multiple satellites and masts all over it.

Ronnie Raygun

Looks like a job for the analyser ...

snaps

Randyleprechaun wrote: »

The way the house is faced in relation to the tower means that I cannot re-site, well at least not any meaningful distance. Suppose I could do it as a trial anyway!!!

It's not just a phone mast either, it's an actual tower with multiple satellites and masts all over it.

Not by any chance Ballinrobe is it? I have lots of problems with the Eircom mast next to the Garda station here. Ive one Polish customer whos dish looks dead straight at the mast (No other place to put the dish as his property where ever you look is in line with the mast) can only get half his cyfra+ channels. Some frequencies have zero signal (TVN transponder being one).
Some other locals on the same road that have sky UK/IRL have problems too with their channels, Discoverys being one batch. The only thing it can be is the mast, ive replaced cable, upgraded dish, lnb, but still nothing.

Its frustrating.

Randyleprechaun

Ballinrobe ya. Just down from garda station a small bit.

Have you seen problems with at the races before round the area.

I was thinking it must be playing some part in the problem.

Thanks snaps

snaps

Randyleprechaun wrote: »

Ballinrobe ya. Just down from garda station a small bit.

Have you seen problems with at the races before round the area.

I was thinking it must be playing some part in the problem.

Thanks snaps

yes its the mast, I've put lots of dishes up there for many different satellite providers. Its certain frequencies that are being knocked out. I was at one of the houses Thursday, wasted an afternoon moving dish, running new cables etc. The frequency and frequencies that are troublesome is around 11.000. Tvn is on 11.393 v. The reciever will show signal, but my meter shows 0db. I know other people doors up and down have trouble with some of the discoverys from sky Ireland.

snaps

Moving dish makes no difference, even people who's dishes are not looking straight at the mast have problems. Even near the cemetary people have problems.

zg3409

I was in contact with a guy before that has similar issues in Dublin with a nearby mast. The phone mast shared the same roof. Normal mobile masts interfere with 800/900/1800/1900/2100 etc. Some microwave links in particular Irish broaband fixed wireless are 10 to 10.6Ghz very close to the real satellite frequencies. I presume he got it sorted in the end.

I had two suggestions

1) Use a fibre LNB. It does not use coax and does not use normal IF frequencies, so may work OK. Quite an expensive solution but would work with Sky boxes.

http://www.globalinvacom.com/products/fibreopticlnb2.php


2) Open the lnb plastic cover and see if there is screws for adjusting the local oscillator frequency. They are somtimes labelled H and L for high band and low band. Twiddling the screws would move the signal in IF, so if the interference is say 1500Mz by twiddling the screw the wanted channels may appear at say 1450 so now work OK. This option is no use for Sky boxes, but other models on a blind scan may pick up the wanted channels at their new location. I can do the maths if you need and supply a modified LNB with know adjustment if known.

For example 11.393 - 10.6 (LNB LO) = 793Mhz which is probably a mobile phone output.

It may or may not solve the problem. The adjustment allowed is very minimal. However may only cost 5 Euro.

Let us know what works

biffontour

I have had a similar experience with At the races on a few installs, an easy way of figuring out where the signal is being Interupting is if you can get a piece of wood or a baking tin or something and move it around the dish. It will block what ever signal is Interupting your signal. Then all you have to do is move the dish so that something is blocking where it is coming from.

Hope this helps

zg3409

biffontour wrote: »

a piece of wood

I would have thought that wood would not block any 800Mhz signals. If it is a 10-13Ghz signal then it might, but they also bounce off walls etc, but hey if it works it works!

biffontour

zg3409 wrote: »

I would have thought that wood would not block any 800Mhz signals. If it is a 10-13Ghz signal then it might, but they also bounce off walls etc, but hey if it works it works!

Only reason I was using a plank of wood was because I was standing from the ground while watching the tv for where the interruption was coming from, seem to work tho

STB

zg3409 wrote: »

I would have thought that wood would not block any 800Mhz signals. If it is a 10-13Ghz signal then it might, but they also bounce off walls etc, but hey if it works it works!

Once he can identify the source ie the mast, he can create an obstacle to block the mast whilst also seeing 28.2. The RF interference issue is due to the fact that the satellite dish is in the LOS of the Phone Mast/repeater.

The solution is to make sure you are using double screened cable and to keep the cable as low to the ground as possible. Move the dish to an area of the house that blocks the satellite dish and lnb away from mast. This may also mean lowering the dish from the top of the house if possible.

snaps

moving the dish doesnt solve the interference. Even without LOS to the mast there is still interference on certain frequencies, not as bad but still enough to annoy.

snaps

I had another call last night from someone different who lives next to that mast. They are having problems with their channels too now. It certainly seems something is now interfering with the satellite frequencies from that mast. The Eircom lads around town have said that Vodafone contractors have been doing a lot of work there recently (The mast is mounted on Eircom land)

zg3409

Maybe it's part of Eircoms TV plans

Step 1 Jam Sky

Step 2....

STB

snaps wrote: »

Moving dish makes no difference, even people who's dishes are not looking straight at the mast have problems. Even near the cemetary people have problems.

The point snaps is that the dish shouldnt be able to see the mast.

I have seen suggestions before that mounting the dish upside down (LNB arm at top) which sets the tilt of the dish so as to not pull in what is presumably the offending H signal.

Of course if the bleed is that strong then the operator of the mast needs to find out why.

There will be much more of this when 4G mast start operating. In the UK the mast operators themselves have set up a fund to pay for filters etc to those affected, but its highly likely that they will not be useful and the situation will be akin to the Wind Turbine affect already being experienced by some.

Ronnie Raygun

STB wrote: »

I have seen suggestions before that mounting the dish upside down (LNB arm at top) which sets the tilt of the dish so as to not pull in what is presumably the offending H signal.

In order to receive the satellite signal, the dish still has to be "looking" on the same elevation, no matter what way up it is.

zg3409

STB wrote: »

I have seen suggestions before that mounting the dish upside down (LNB arm at top) which sets the tilt of the dish so as to not pull in what is presumably the offending H signal

I have mounted dishes upside down for hobby land to land microwave TV links. The brackets used and setup is very different. I would normally recommend a plastic bottle over the LNB to stop water problems.

It mentions here an upside down dish
http://www.satcure.co.uk/tech/upside_down_dish.htm

and that it might reduce terrestrial interference

I would have thought that mounting the dish upside down would have no effect on it's beamwidth, direction or sensitivity to signals from an angle. It might be that the dish could be mounted a little closer to the ground to hide nearby unwanted signals, but I am doubtful.

Of course if the bleed is that strong then the operator of the mast needs to find out why.

There will be much more of this when 4G mast start operating. In the UK the mast operators themselves have set up a fund to pay for filters etc to those affected, but its highly likely that they will not be useful and the situation will be akin to the Wind Turbine affect already being experienced by some.

Operators are allowed to transmit at high power at 800/900/1800/1900/2100 etc. They are the righful users of these bands. The IF of receivers and LNBs use these frequencies. Putting a filter inline would only block wanted channels on the receiver.

A filter would be of use for Saorview and UHF masthead amplifiers as they do not need 800Mhz and above, and so it could stop problems ocurring. So filters are of no use for this problem.

If possible a spectrum analyser should be used to identify the problem frequencies and then methods attempted to reduce or elimiate the problem, comparing one method to another.

As I already said a fibre LNB does not use 800-2100 frequencies on the cable, but is very expensive. A cheaper option for non Sky users is to tweak an LNB so it shifts the frequncies slightly by even 50Mhz which might solve the problem. This is fairly easy to do and very low cost.

A larger dish might improve the wanted signal, so might help if it is marginal.

STB

zg3409 wrote: »

I have mounted dishes upside down for hobby land to land microwave TV links. The brackets used and setup is very different. I would normally recommend a plastic bottle over the LNB to stop water problems.

It mentions here an upside down dish
http://www.satcure.co.uk/tech/upside_down_dish.htm

and that it might reduce terrestrial interference

I would have thought that mounting the dish upside down would have no effect on it's beamwidth, direction or sensitivity to signals from an angle. It might be that the dish could be mounted a little closer to the ground to hide nearby unwanted signals, but I am doubtful.

Operators are allowed to transmit at high power at 800/900/1800/1900/2100 etc. They are the righful users of these bands. The IF of receivers and LNBs use these frequencies. Putting a filter inline would only block wanted channels on the receiver.

A filter would be of use for Saorview and UHF masthead amplifiers as they do not need 800Mhz and above, and so it could stop problems ocurring. So filters are of no use for this problem.

If possible a spectrum analyser should be used to identify the problem frequencies and then methods attempted to reduce or elimiate the problem, comparing one method to another.

As I already said a fibre LNB does not use 800-2100 frequencies on the cable, but is very expensive. A cheaper option for non Sky users is to tweak an LNB so it shifts the frequncies slightly by even 50Mhz which might solve the problem. This is fairly easy to do and very low cost.

A larger dish might improve the wanted signal, so might help if it is marginal.

I was suggesting the upside down dish so as to prevent unwanted RF being received on the LNB from the phone mast. Where does terrestrial come into this ? Moving the dish low to high will point to horizontally polarised IF.

I am fully aware that the download frequency of the LNB and the broadcast frequencies of the mast are common (this is the whole issue). I never suggested that a filter would be a solution for satellite. That is the solution that is put being forward for filtering out TVI from 4G on UHF in the UK.

Rightful users ? That does not mean that you can interfer with other spectrum users. Given that the majority of the base station installations are operating @ 65dbm eirp, many of them with exemptions from PP from planning authorities from years ago, I would make it their problem.

If one of these is that close in proximity to wipe out a weak transponder such as ATR or CBS channels, then interference is the least of your worries.

@snaps I presume its the Vodafone MOBRE installation in Ballinrobe opposite Petes PCs ?

Ronnie Raygun

STB wrote: »

I was suggesting the upside down dish so as to prevent unwanted RF being received on the LNB from the phone mast. Where does terrestrial come into this ? Moving the dish low to high will point to horizontally polarised IF.

Phone masts tend to be terrestrially based ... Do you mean the upside down dish might be less susceptible to ground reflections, or what?

Also, what do you mean by the part I've bolded?

snaps

Yes its that mast. Its a huge mast with many types of stuff on it, microwave dishes, cell sites etc.

The houses are the other side of it. Nearest house less than 100m away, possibly closer.

snaps

Another call yesterday from a new tennant next to this mast. I knew before i turned up we would have problems. His house looked like it had been machine gunned as the were holes drilled all over it where dishes had been moved to try and get good signal. Firstly i showed him that wherever the dish went on his land it was looking straight at the mast (Row of houses on the north of dish, satellites right behind mast), so Hotbird which he needed was sitting right behind the mast. I showed him the frequencies on my meter that were non existent, then walked 300m or so down the road and showed him the signals were much improved (We must have looked strange carrying a dish waving it around on the side of the road!). He still didn't understand, but put a dish up anyway leaving him with only half of his channels receivable. I wasnt happy with it, but the chap insisted I put the dish up.

steveon

snaps wrote: »

Another call yesterday from a new tennant next to this mast. I knew before i turned up we would have problems. His house looked like it had been machine gunned as the were holes drilled all over it where dishes had been moved to try and get good signal. Firstly i showed him that wherever the dish went on his land it was looking straight at the mast (Row of houses on the north of dish, satellites right behind mast), so Hotbird which he needed was sitting right behind the mast. I showed him the frequencies on my meter that were non existent, then walked 300m or so down the road and showed him the signals were much improved (We must have looked strange carrying a dish waving it around on the side of the road!). He still didn't understand, but put a dish up anyway leaving him with only half of his channels receivable. I wasnt happy with it, but the chap insisted I put the dish up.

Hard to beleive nothing is being done about this.....dont pity ye installers near there....

snaps

steveon wrote: »

Hard to beleive nothing is being done about this.....dont pity ye installers near there....

nothing can be done really. It affects about 15 houses at a guess. Just luck of the draw.

steveon

Have a similar problem but its in county Limerick affects about 20house in a half mile radius definetly some form of landbased signal causing problems

snaps

I think its a bit of both here in Ballinrobe. Loss of signal due to the Mast itself blocking the signal (When in line of sight), but recently new microwave dishes have been put on the mast which seem to be causing radio interference too for others not in line of sight but near enough.