All posts by Michael Perry
Below are all of Michael Perry's postings, with the most recent are at the bottom of the page.
Susan
Professional TV engineers always used to carry a selection of attenuators, from 3 dB up to 48 dB and they can simply be connected in series. Good ones can be bought online quite cheaply so a small selection might halp - else you would need to get a variable type that you can adjust for best results.
It's not the box causing any 'interference' but the way they react to signals that are too strong or too weak - neither are a good thing! Whilst the 'Goodmans' branded boxes are inexpensive they are not the best on the market, nor the worst probably. It's said to be true that they don't react well if there is too much or too little signal. The need is to get the right balance between strength of the signal and quality of the resulting pictures. Hence selecting the right level of attenuation is important if your signal is too strong.
| link to this comment |
MikeB & Susan:
If you buy coaxial in-line attenuators they have a male connector at one end and a female at the other - you just plug them together one after the other if you need more attenuation. One possible is at 12DB COAX PLUG INLINE ATTENUATOR: Amazon.co.uk: Electronics Note that these have standard coaxial connectors so you can plug them in without needing any extra cabling. They are available in various degrees of attentuation, the normal range is 3, 6, 12, 18, 36 and 48 dB attenuation and that other suppliers are available.
Note that these are only intended for use with the UHF TV signals such as Freeview - they do *not* work with connections to satellite dishes!
| link to this comment |
Philip C:
Your starting point should be to ask your neighbours who also use Freeview (and not Sky or FreeSat) if they are getting the same effects. If they are then it's not you equipment. If you are using a communal aerial system like the neighbours you ask there may be a fault in that system that needs the attention of a specialist engineer engaged by the property owners. If, however, your neighbours have the problem and are using theor own separate aerials then it could be atmospheric problems that often occur with hot weather.
| link to this comment |
Jamie:
2-way broadband via satellite has been around for more than 10 years! From 2003 I worked for 3 years in Salisbury for a training services provider and we had all our internet connections via a 75 cm satellite dish that handled both downloads and uploads. It was never very fast and quite expensive at the time. It was eventually replaced by a pair of ADSL dedicated lines 'bridged' to give decent performance for the needs of 8 trainers and training designers.
| link to this comment |
Miss Linda Glease:
The simple answer is no, not all the Freeview services are available via the internet. To view them you need equipment designed to receive the UHF signals and to decode them from the digital format into sound and picture. That requires a Freeview equipped TV set of esle a box designed for Freeview reception.
Likewise, your Acer Tablet computer cannot of itself receive and display FreeSat programming.
| link to this comment |
Ade:
It does not appear in the programme listing on my Sky HD box, so I doubt it is generally available. But I live in Wiltshire so I suspect that few would be interested in RTE as they would generally appeal to those interested in Irish programming and affairs.
| link to this comment |
Anthony
The signals being transmitted are still UHF signals but with a different modulation method, so that does not affect the design of the aerial used to transmit or receive Freeview signals. The selling of aerials as being 'digital' has been shown to be more a marketing ploy than a technically required reality.
The older Yagi (or more accurately a modified Yagi) is perfectly capable of receiving the 'new' signals. However, it would be wise these days to fit a log-periodic rather than a wide-band Yagi. The simple reason is that with the planned or proposed changes over the next few years a Yagi designed for one group will not necessarily be suitable for the future frequencies to be used at some transmitters as the group may become unsuited.A Log-Periodic, on the other hand, is ideal as it will already be able to receive *all* the Band 4 and Band 5 transmissions into the foreseeable future. The modulation method does not affect the transmission or propagation of the signals.
However, the data can be more 'awkward' to decode and that is shown by some enquiries on this site where the signal strength is too high (but still less than 100% being shown on some receivers). In such circumstances, many receivers show an inaccurate message usually claiming there is no signals, what it really means is that the receiver cannot satisfactorily decode the signals.
It is not common to require an aerail amplifier unless the reciver is some distance from the transmitter. Even a 24 kW ERP will be perfectly receivable and decodeable at quite some distance if there are not obstructions, such as hills or trees or buildings, to 'block' the signal path.
Looking at the Winter Hill data at the top of this page I cannot see any of the Muxes being transmitted at 24 kW. Which transmitter are you referring to?
| link to this comment |
KMJ,Derby, jb38 and Briantist:
Readability of answers/responses of a necessarily technical nature will likely be scored as 'almost unreadable' as the general population have poor understanding of the more complex technicalities involved. As I understand it, the scoring system looks at how 'readable' our comments are from the perspective of 'general public' levels of understanding. What we who know something about the television systems regard as essential technical content is regarded by many as 'jargon' and so dismissed - in my view largely because they can' understand the basic principles involved. However, keen amateurs (the 'radio ham' types) go and find out if they don't understand something.
I'm sure all my posts 'fail' the test too, but I do try to be technically accurate (if my old memory cells allow).
| link to this comment |
Martin If you think it might be due to 4G signals, contact at800 on https://at800.tv/. If yiou are likely to be affected they will know and if necessary will supply one free filter to fit close to your aerial. According to the mapping alongside your post there are 5 masts within a relatively short distance, click on the "M's Freeview+4G map" entry or go to Map of Freeview reception at G781LN | ukfree.tv - 12 years of independent, free digital TV advice for more information. But none of the masts are specifically listed as being 4G though they may well be. Checking with at800 is your first step I think.
| link to this comment |
Monday 30 June 2014 8:19PM
Brian Chandler:
It is worth switching off your box, unpluging iot from the mians supply for at least 5 minutes and then plugging it back in and switching on. Let the system reset itself and then try seeing what channels are available. It may be a 'glitch' in the receiver's software operation that will be reset by the above procedure.