All posts by Michael Perry
Below are all of Michael Perry's postings, with the most recent are at the bottom of the page.
Nick Horrex:
You can get log-periodic aerial of up to 56 elements with commensurate higher gain than those with fewer elements. I use a Log36 but my brother uses a Log48 as he is further away from the transmitter than me. Our uncle now uses a Log56 as he is even further away in a different part of the country. I must admit that such aerials a not easy to find though. However, a variable gain amplifier can resolve weaker reception as long as there is no local interference present.
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Christel Haddon:
F1 will only be on Sky Sports via a subscription as far as has been revealed so far. Not being a fan of Riugby, I can't say whether it it will be available or how.
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Nick Horrex:
A log-periodic aerial uses ALL the elements for reception of ALL the available channels across the UHF bands. It is not the case only some are used for some frequencies - the way a log-periodic works requires all the elements to be correctly in place. The number of elements affects how much inherent gain the aerial has, the more elements the higher the intrinsic gain.
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Bren:
An aerial has to be either horizontally polarised or vertically. The main boom, carrying all the other elements, has to be virtually level with maybe a little uplift at the end furthest from the dipole where the cables are connected (on a log-periodic the cables usually enter at the other end). It must never be vertical or even nearly so as it must 'look at' the transmitter mast at Waltham or Sutton Coldfield - it can't do both but a 'side lobe' may give you some unexpected reception though at low strengths.
The decision about whether the small elements across the main boom should be horiziontal or vertical is determined only by the transmitter aerials. At Waltham, and at Sutton Coldfield if you are getting West Midlands news, the transmitting aerials provide only horizontal polarisation. Therefore all the smaller elements mounted across the main boom *must* be horizontal. If you tilt them at 45 degrees you will lose some or several signals and others will be weaker, perhaps too weak for reliable reception. The angle of the roof of your house is irrelevant.
Ideally you should move your aerial as far away from all water tanks and pipes as is possible whilst still being aimed directly at the wanted transmitter, at a bearing of 123 degrees for Waltham or at 231 degrees for Sutton Coldfield. Both transmitters can be well received in West Bridgeford (I used to work in the Nottingham area when I was a TV Service Engineer) but Waltham is best as it carries the East Midlands services.
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Nick Horrex:
Yes. The way the elements react to the wanted signals is crucial and they are designed to all react to give the required gain at the frequencies covered. They *all* add something to the strength of the wanted signal to varying degrees. Those behind the most active element are essential reflectors and there can be several at the higher frequencies but they are all required, so none are 'redundant'. Those in front of the active element act as directors and are again essential for satisfactory reception. That is unlike a Yagi design where a dipole is the only active element and is a compromise, especially on a 'wide band' Yagi or modified Yagi design. Because they are a compromise, the strength of the received signals varies quite a lot across the band claimed to be covered, which is why they are not liked by TV engineers.
A good high gain log-periodic is alweays better than a Yagi for wide band reception - which is what we will all have as Arqiva adjust the transmitters to allow for the 4G signals in the 700MHz band.
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Christine Clarkson:
Please check all your aerial cables and connections to ensure they are making good contact inside the sockets. Also try turning all your TV equipment off at the mains socket, wait five minutes and turn on again. After a further five minutes check to see what channels you can get. If that does not solve the problem your system has a fault that needs to be looked at by a qualified contractor.
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Julie Hedges:
Please contact ITV directly, not this website. Further, do not give your email address publicly as there are occasionally some pople accessing this website and posting inappropriate material. If they use your email address you could be bombarded with unwanted spam.
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Edith O'Dell:
Try contacting True Entertainment directly. This website is not responsible for any programme output from any broadcaster, it is intended to give reception advice.
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Bren:
You cannot simply join two different aerials together in parallel - that ruins the impedance matching which *must* be maintained at 75 Ohms. An impedance mismatch reduces the available signal very considerably and is to be avoided at all costs. One possibility is to use a diplexer but they are very 'lossy' as they reduce the signal levels for each input or output by 67%! The better alternative is to have each aerial with its own separate feed into the room where you view the TV and fit a coaxial switch so that you can select one of the aerials at a time.
However, the digitaluk trade link below you posts show that reception from the Nottingham transmitter, located near Nuthall, is variable to very poor. It's just too far away from West Bridgford and there are hills in the way. It is also a lower power transmitter and only provides 6 multiplexes, so potentially fewer channels.
If you can arrange that your aerial does not try to look through brickwork you're likely to get better results, tiles and roof cladding absorb less signal than solid bricks. As you appear to be on Radcliffe Road, I'm surprised you have reception problems as you should have a clear view towards the Waltham transmitter, with only the bulk of Trent Bridge Cricket Ground to avoid, but most of Radcliffe Road is well away from that. I also know for certain that reception in Lady Bay is excellent.
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Wednesday 7 February 2018 11:08PM
MikeB:
Most of it is offensive rubbish and of no relationship to this website so I hope Briantist will delete all of it soon.