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| Thread ID: 84542 | 2007-11-09 18:27:00 | Ghosting tv image | Mike (15) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 609849 | 2007-11-09 18:27:00 | We've just moved into a new house and while we get all the channels on the tv fairly clearly (no noise), a couple of them have a slight ghosting on them. Is it possible to fix that? Cheers, Mike. |
Mike (15) | ||
| 609850 | 2007-11-09 19:41:00 | We've just moved into a new house and while we get all the channels on the tv fairly clearly (no noise), a couple of them have a slight ghosting on them. Is it possible to fix that? Cheers, Mike. You could try realigning the aerial - I assume it is on the roof. Its an aerial problem so if pointing it in another direction does not stop the ghosting, you will need a new aerial. Check all connections and coax while you are up there but if faulty these will degrade the overall signal but not cause ghosting. |
Morpheus1 (186) | ||
| 609851 | 2007-11-11 04:06:00 | Ghosting is caused when the signal is bouncing off something else and coming at your aerial twice from 2 different places.. a hill or someone elses roof etc. might not be much you can do about it, repositioning the aerial may work, but then other channels might turn to crap. |
Agent_24 (57) | ||
| 609852 | 2007-11-11 09:27:00 | Ghosting is caused when the signal is bouncing off something else and coming at your aerial twice from 2 different places.. a hill or someone elses roof etc. might not be much you can do about it, repositioning the aerial may work, but then other channels might turn to crap. A correctly designed antenna will eliminate ghosting. A local aerial specialist will know which type will suit. |
Morpheus1 (186) | ||
| 609853 | 2007-11-11 09:39:00 | Ghosting Better picture or sound quality can sometimes be obtained by altering the alignment of the aerial. This will require someone to watch or listen for the best reception whilst the aerial is slowly pointed from side to side, up or down, or twisted. If that is unsuccessful, it is usually possible to find another position for the aerial which results in better reception. There are aerial configurations that null unwanted signals. Talk to your aerial specialist for information on these. Poor installation of an antenna and cabling can also cause create ghost images. A faulty joint or improper cable connection will often cause ghosting. In some cases, the phenomenon may persist regardless of the type of antenna used, because the unwanted signal may be very strong. Where the problem persists, ask an aerial specialist if there is another type of aerial available, which may be more suitable for reception in your area. In severe cases the most effective option may be to fit a satellite receiver and dish combination. :) |
Trev (427) | ||
| 609854 | 2007-11-11 17:15:00 | it is usually possible to find another position for the aerial which results in better reception. There are aerial configurations that null unwanted signals. Good point. I forgot about this. It means moving around on the roof holding the antenna above your head (on a mast), and possibly on top of the garage or other places to find the null point. Most aerials are mounted on a chimney or with wall brackets. If the null point is in the middle of the roof it could be difficult to mount. Trev, would poor quality coax allow signals through the shield, causing ghosting? I had not thought of this possibility. |
Morpheus1 (186) | ||
| 609855 | 2007-11-11 20:38:00 | Coax is not usually affected by parallelism or induced signals..hence the name CO-AXIAL..to eliminate signal getting to the core wire thru the shield. The ghost problem, when it was related to cables was usually the old 300ohm stuff...remember that flat two-wire molded stuff? If you didn't impart a certain twist into the flat cable and have the standoffs just right, you'd get ghosts and snow by accident. Coax has little problems along that way. There MAY be a complete open in the shield if you tried to splice the coax together...it can be done, but you gotta be good! Adding connectors is also problematic if done poorly. Usually though..antenna placement is at fault..and it might be a large hill or neighboring building that is reflecting the signal late to your receiver too. Sometimes, there is another channel on the same frequency that is crawling into the back end of your tuner...that's not too easy to correct without attenuation devices..etc. |
SurferJoe46 (51) | ||
| 609856 | 2007-11-11 22:49:00 | You can get differant types of 75 Ohm cable. 75 ohm air space TV coaxial cable for low signal areas, and 75 ohm heavy duty RG-6 Quad which has less atenuation used for when you need a long antenna lead. :) |
Trev (427) | ||
| 609857 | 2007-11-12 00:41:00 | A correctly designed antenna will eliminate ghosting. A local aerial specialist will know which type will suit. An appropriately designed antenna may minimise ghosting, but if the source of the ghost reflections is within the main beam of the antenna some ghosting will remain. No antenna can eliminate ghosting, it can only minimise it. Mitsubishi marketed a NZ designed and manufactured digital ghost removing system here under their Black Diamond brand name that really did remove ghosting. It relied on a special signal transmitted during the sync pulse interval and it was stunningly effective, but sadly it did not last long on the market. It appears kiwis were happy to tolerate ghosting. In my TV repairing days it was not uncommon to be called out for a rolling picture but no mention of ghosting and when you got there the picture was virtually unwatchable. You had to demonstrate a stable image using a pattern generator (or even rabbit ears) to convince them that their signal was the problem, not the TV. Cheers Billy 8-{) |
Billy T (70) | ||
| 609858 | 2007-11-20 05:39:00 | Would it be spamming? to say about my new forum discussing such matters? www.dtvforum.co.nz | apsattv (7406) | ||
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