Ghosting

Darby OGill

I get "ghosting" only on Network 2. It is not as bad as it used to be, but still quite noticeable on dark/black pictures. I have a good-sized aerial in the attic, and RTE 1, TV3 and TG4 are fine. Any ideas/suggestions?

Robert

I get lines only on Network 2 I live quite high up and have a new aerial up high no my chimney with a booster. RTE1, TV3, TG4, Channel 4, UTV, BBC1, BBC2 are all perfect picture. The pictures goes through a vcr RF Modulator and sky box.

lines are co-channel interferance usually ie, another station / channel on the same frequency interfering-very little can be done about it.

Regarding ghosting,a lot of this has to do with the confined space of your attic, signals bounce around the walls, you are lucky it's only affecting one channel.
The only surefire way to get rid of it is to mount the aerial outside, even by mounting it to a wall facing the direction you are getting the signal.
mm

Darby OGill

I'm in the middle of Kildare. Where are my RTE etc. signals coming from? Kippure?

watty

I get ghosts on RTE1. I'm sure it is RTEs fault as sometimes the picture is ghost free. (I have professional Chimeny mounted aerial).

RTE's transmission network is not as good as they think it is.


You need an outdoor aerial. With indoor, set-top, or attic you will almost always have ghosts to greater and lesser extent on all channels.

Outdoor Log periodic aerials reduce ghosts caused by mulitpath reception. A high gain yagi aerial can make ghosting worse as it has "side lobes" that can pick up a reflection from Hill or Building.

Ghost types (A ghost is a fainter shifted copy of the picture):
1) Single sharp & bright ghost (perhaps some equally spaced fainter ones): Bad connector, damaged cable, RTE transmission fault or reflection from nearby building.

2) Diffuse changing Ghosts: Signal going through big trees. Esp. if is gone by end of November and comes back in Spring /summer.

3) Intermittant Ghost with picture shake: Aircraft. I suffered this in Co. Clare only from Concorde Air France training flights.

4) Soft faint Ghosts. Further away trees in path or reflections from hills / tower blocks farther away.

Co-Channel Interference:
Mild: Faint static herring bone pattern (common on Cable)
Medium: Faint Moving diagonal lines and patterning
Severe (any of) : Rolling grey to black bar, sound buzz, Negative picture appearing in background, Severe colour flicker and losing colour intermitantly.

Sometimes the TV tuner is "overloading" and 6dB or 12dB inline barrell 75 Ohm attenuator will cure "mild" or "medium" completely. If the interfering channel is actually on the same frequency an Attenuator will not help.


Interference (Ingition etc, Motor bikes are worst).
Moving white flecks all over picture.

Darby OGill

Watty, type 4 best matches the effect I'm getting- the ghost image is faint and only obvious on very black/dark images. I assume it's not a tv fault.

My attic aerial (must check make/type!- but I'm pretty sure it's for indoor use only) points east-west, and signal must come through gable wall/roof (dormer bungalow). I've moved it about to ascertain optimum position and the picture quality is generally excellent on all four terrestrials. Recently a tv installer was in the house (social visit) and remarked that the picture quality was remarkable when I told him the set-up.

The co-ax from the aerial has a joint (two different types!), and is then connected to a mains booster (Mercury model)- does any of this make a difference in your opinion?

From your explanation , I would say that if you had even a cheap outdoor aerial,your reception would be crystal:)

You are probably getting your signal from Kippure, which would come in on a portables telescopic anyway.

Are you trying to avoid the licence man or summat:D or is there a reason why you won't just throw an aerial onto the chimney, especially when you have installers arriving on social visits...
mm

Darby OGill

I have a TV licence more's the pity, so none of yer oul' snide comments.

The problem is not so bad that I could be arsed to put an aerial on the chimney- I'm just looking for the easy way out as usual.....

To be honest, since I got the FTV card, I've hardly watched any terrestrial TV. None of dem ghost fellas on satellite so far- unless you count that creepy bloke who presents the antiques show thingy, (on BBC I think). Now he's scary.......... :eek: