ITV reception problems

[ABT89R]

I am glad that ITV is now being beamed, unfortunately I can't view ITV1 at all as the picture breaks up and freezes continually, ITV2 fairs little better. I suffered similar problems previously with Sky News but the fitment of a signal attenuator in line cured this.

I would be most grateful for any help and advice that anyone could offer me on how I might cure this latest problem.

Thanks.... ABT89R

 

[w hole]

Hello Fellow Charter Member

First : Tell us where you are.....

Regards ;~}

W Hole

 

[rolfw]

[updated:LAST EDITED ON 24-Nov-01 AT 07:15 PM (GMT)]Hmmm, can't remember which part of Germany you are trying to receive from, but perhaps you are suffering from the double edged sword of too much power on some channels and too little on others. Try taking the attenuator out and see what happens with the new channels. I believe the new channels are on the 2D satellite, so the footprint is very restricted.

Rolf

 

[ABT89R]

Hi,
please excuse the omission. I am in Rhineland Pfalz Germany, on the Rhine, at latitude 50.4009 and longitude 7.6126 to be exact.

I tried it with the signal attenuator removed and the results were even worse.

ABT89R

 

[ABT89R]

I have spoken to other people in this area with Sky and they have no reception problems with ITV1. They are using the mini dish, I use a 60cm mesh dish. My local satellite equipment dealer said that my dish is not ideal for digital reception, and that I should change it to an 80cm dish.

Anyone got any thoughts or comments please?

Regards.. ABT

 

[rolfw]

May be right, but possibly more to do with the LNB. The older universal LNBs are not as stable as the newer ones which are designed for digital reception. The dish may also be slightly malformed, so you would receive some frequencies well and others less so.

Rolf

 

[ABT89R]

Hi Rolf,
the LNB was replaced when I changed from analogue to digital this year, so that shouldn't be the problem. There is no obvious distortion to the dish that I can see, apart from a bit of deformation on the perimeter lip, but I don't know how much distortion is needed to cause a problem. It won't cost too much to get an 80cm dish anyway.

Thanks! ABT

 

[rolfw]

Well, it's got to be one of the two ABT, particularly if someone closeby is receiving without difficulty. So changing the dish will certainly do no harm, the LNB may be new, but could still be of the older design, there are still LNBs being sold that are not specially designed for digital reception. Remember that the German analogue sat industry is still flourishing.

Best of luck,

Rolf

 

[Channel Hopper]

First try changing the connector on the end of the cable and see if there is any water inside the line.

If your neighbour is a friend of sorts, I would ask to swop out receivers as it could be a fault in the tuner at the frequency of ITV. Go to his house first with your receiver as this will look as though you are checking the indoor equipment rather than using his receiver as a test piece of equipment.

If nothing can be found then I would then run another cable to the dish , nothing fancy, just a loose line, this would show if the problem is the cable, a nail, water again, or maybe a kink where it goes round a corner.

 

[Deleted]

Has anyone had any success receiving ITV as far out as Berlin? Apparently is is possible to receive a clear signal using an 80cm dish in Brunsbüttel (western Schleswig-Holstein), so there must be some hope for Berlin, or am I being too optimistic?

Is it possible to receive ITV regions other than those meant for the area for which the card is coded?

Let's hope it doesn't occur to anypone to put the BBC signals on that pesky #*&&%@ narrow-beam satellite....

Qwerty

 

[rolfw]

[updated:LAST EDITED ON 27-Nov-01 AT 06:40 PM (GMT)]@ABT, As Channel Hopper says, it is worth checking things like the cable and connectors, but I seem to remember that your signal strength and particularly quality were all good on the other channels, so it's possibly not that. Another good reason for using one of the newer dishes is the width of the beam, the Sky minidish is designed to work well in siuations where the satellites are parked close to other sat groups, thereby receiving less in the way of spurious signals, I think that this is an issue for the future rather than the here and now. Also try going into manual tuning, Services/system setup/01Select/Manual tuning, enter the transponder settings and it will give you a signal strength and quality reading specific to that transponder.

@Qwerty, If you look further down the page for postings by Mark alias mljgmljg, he I believe lives in Berlin and has problems with the 2D transmissions. With regard to the regional version, they are all available through other channels, but you should be able in most circumstances to get the nearest other region on 963

Rolf

 

[ABT89R]

Hi, I have managed to fix the problem. I removed the equalizer that I had fitted, this was 12dB to 1dB and replaced it with an adjustable one from 0.5dB to 20dB. As soon as this was fitted the reception was perfect, I didn't even have to adjust the trimmer pot'.

ABT

 

[w hole]

Hello All

What is an Equalizer, what purpose does it serve, and how/where is it fitted?

Regards

W Hole

 

[rolfw]

[updated:LAST EDITED ON 02-Dec-01 AT 02:01 PM (GMT)]An Equaliser will normally allow for high frequency signals to arrive at the required destination at the same signal strength as their less attenuating lower frequency brothers. ie putting a slope in the signal strengths. The higher the frequency the bigger the transmission and cable loss, so the equaliser attenuates the lower frequencies to a larger degree than the higher frequencies.

An attenuator reduces all frequencies equally.

An Equaliser is ideally fitted at the beginning of the cable run for best results, but can be fitted at the box, the attenuator will work at either end of the cable.

Rolf

 

[w hole]

with you so far R.

but what is the reason for Attenuating the lower frequencies?

Regards

WH

 

[Channel Hopper]

A slope equaliser will not attenuate the lower frequencies so the notation is incorrect

The fitting of these should only be done where there is a long run of cable between dish and receiver. The near linear output of gain from the LNB is attenuated more at higher frequencies when it passes through the cable. I assume a trimmer is used to best mimic and reverse the effects of the cable (adjustment based on length and size of cable)

The slope of the equaliser is designed to reverse the tail off at the top, giving the receiver something at all frequencies, however they also add noise, and if the signal is not good to start with, it wont help pull out the signal from the background

Since Germany is not far from Poland, it would be easy to get a cheap dish in steel (1m or 1.1m) from over the border for about the same price as an equialiser, and then you could guarantee perfect reception regardless of the cloud cover.

 

[w hole]

Hello All

I know I'm thick, but I still can't quite make out why someone would want to use this device.

What 'practical' purpose does it serve?

Regards

W Hole

 

[rolfw]

To answer your question W Hole, assuming that a receiver has a lower and upper threshold for signal reception, a signal received outside either is unusable.

On long runs of cable, the higher signals suffer much greater from loss and so when they arrive at the receiver they fall well below the levels of the lower signals. To enable both sets of signals to fall between the acceptable strength thresholds of the receiver , it is occasionally necessary to equalise them, ie to make sure that they are of similar strengths when they reach the receiver. An analogy (for equalising on terrestrial UHF systems anyway) is the handicapping in a horse race, the expected faster horses carry lead weight so that the lesser horses will be able to keep up and a closer finish is accomplished.

I have never yet had to use equalisation on a satellite setup, as very seldom have I had a cable run of more than 50 metres, but I'm sure the situation must arise occasionally.

@Channel Hopper You unquestionably have more in depth knowledge than I, if it doesn't equalise by attenuating the lower frequencies, how does it achieve the required results?

Rolf

 

[ABT89R]

@W Hole - the device I replaced was an equaliser, and I replaced it with a variable attenuator. To answer your question "why would someone fit such a device?" Very simply, and not being technically au fait with all this, I fitted it to cure a reception problem that meant certain channels were unviewable.IT WORKED!

Regards,
ABT

 

[Channel Hopper]

Dear Rolf

The characteristics of the semiconductor and filter system inside the line amp (or equialiser) mean that the amplification of the frequency spectrum has a slope to it (hence slope equaliser) The upper frequencies are not amplifed as much as the lower ones

In almost all cases Ive seen these units are sold over the counter as a quick fix solution, - its quicker and cheaper than replacing a bad run of cable, and since they cure the one problem the punter has been experiencing, its unlikely they are returned when another fault crops up. Running thicker wire has far more benefits from a signal point of view

No substitute for a bigger dish though, you get more gain at the front end and less noise.