All posts by Michael Perry
Below are all of Michael Perry's postings, with the most recent are at the bottom of the page.
Nicholas:
Having worked in the TV electronics and software industries in technical roles all my working life I am able to make most things in wood, metal, ceramics, etc. I have built many electronic devices over the years ranging from radios, TVs to transmitters and audio high fidelity amplifiers.
When designing an aerial dipole, the shape and dimensions are critical so it covers the frequencies wanted, any variation can give unexpectedly poor results. A piece or copper wire is not suitable for use other than for a very narrow range of frequencies and then only if it is accurately shaped.
Under the Electrical Interference legislation, aerial amplifiers shouyld be imune from such interferenec, but cheap ones are susceptible.
Your 'solution' is not suitable for general use but some may wish to experiment, as you did.
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Dave Wayman:
Your TV has tuned to a different transmitter in all likelyhood. If you give a full post code we would be able to see where you are in relation to the range of possible transmitters.
To solve your problem you need to manually tune the offending channels on your TV set, the User Manual will tell you how to do that. Check which channels the multiplexes are broadcast on by looking at https://ukfree.tv/transmi…ill.
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Hafizur Meah:
You should find it on Logical Channel Number 114 if your TV set is a Freeview HD type (not just 'HD Ready'). The other requirement is that the transmitter you are using carries COM8 - not all do.
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Nicholas:
Your assertions about using copper at UHF does not fit the known physics of aerial design.
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Martin morgan :
Indoor aerials rarely give useful results in my extensive experience. It's a question of signal strength, not distance. 8 Miles from a smaller transmitter could well be too far away. If it is a main transmitter it could still be too far. You're better off with a properly installed roof aerial of log-periodic design.
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Iggy:
Then you only need to fix the twin cable to the external wall where it cannoit easily be reached by casual walkers. You can get fixings for twin cables easily, they are designed for twin coaxial cables so are wider than those for single coaxial cables. It is wise to maintain the twin feeds in case you wish to record one channel whilst watching another.
Note that you cannot 'split' satellite coaxial cables because of the way the control systems work for each individual element within the LNB (the small 'box' mounted in front of the dish face). The TV or Set Top Box (STB) controls the receiving elements within the LNB to get the services wanted for that device. If two devices wanted different services they would conflict and could possibly damage the LNB and maybe the receiver as well.
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trevorjharris:
Please check the range of people who have a legal right to gain entry to your property, there are more than you think. Many Government officials have the right to enter, as do Customs Officers, Immigration Officers as well as Police Officers in certain circumstances. They do not always need to obtain a warrant to be allowed entry and if you refuse them you could be committing an offence.
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Tony Hill:
Check all the cables and connections between your aerial and TV set. There could be a poor connection and by just removing and re-inserting the plugs that can resolve the issue. Also check for any damage to the aerial cables. You should also check that your TV is tuned to the correct channels and what the signal strengths are. Too much signal, or too little, will cause the symptoms you report. The ideal strength is between 60% and 85%.
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Bill McDonald:
I also use the Mendip transmitter but live in West Wiltshire, so I'm probably further away from the transmitter. However, we don't have any problems with receiving COM7 or COM8. We use a Log36 aerial aimed carefully at the transmitter and to avoid any local trees.
It could be that trees may be the cause of your problems, especially if your aerial is slightly off line.
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Tuesday 15 August 2017 10:58AM
nicholas:
This is not generally a good idea. The replacement dipole element needs to be exactly the same domensions and shape as the removed aluminium one, mounted at exactly the same position as the old one and in the same orientation of course. Further, copper develops green verdigree on exposure to the atmosphere and that is a very poor conductor. Plus there could well be electrolytic reactions between the copper and the terminals unless they are all plated to prevent both corrosion and electrolysis.
The best way of improving reception is to use the correct aerial, mounted correctly outdoors, aimed accurately at the transmitter and properly connected using good quality cables.