February 12, 2015 at 4:05 pm #1057940General LightingModerator
I read recently that whilst a lot of younger folk (in USA?) listened to “linear radio” content (i.e a radio show presented by a DJ or a sequence of mixes via a certain stream at a certain time); many now find the concept of buying a radio receiver (that isn’t also a smartphone/tablet etc) totally alien.
It often only when they start to drive motor cars do they encounter traditional radio – there is usually a set in most vehicles; but the poor quality of content is more likely to encourage them towards connecting their personal audio player to a €6 china “legal pirate” transmitter (which ironically is setting up a radio station of their own!)
Sports fans in UK may well purchase or use a transistor radio to listen to football (soccer) or cricket commentaries on the medium and long frequencies (cheaper than a satellite subscription). There is DAB in Britain but currently its shite – some stations use 80kbps mono MP2 encoding for EDM and that sounds rough; and portable receivers are expensive and if they can even run on batteries/accu they do not last long.
Of course today you can listen to your favourite music with streaming at very good audio quality (often better than Band II FM) and sometimes even on mobile devices (if your network can handle it) – but I increasingly feel that every would be AV engineer should own at least one analogue portable radio receiver.
It need not be a high tech world receiver like the Tecsun I just bought – a €6 transistor radio from ASDA will serve just as well. Or borrow one from your parents/grandparents! You want the sort of receiver that will run from its own internal batteries.
Apart from the fact by tuning you may still discover something interesting on an odd frequency (a pirate, a foreign station you might not normally receive due to atmospherics; radio is also a good way to learn languages); it is a very useful low cost piece of test equipment for unearthing sources of interference; that can make the rest of your AV kit sound bad or otherwise malfunction.
As an experiment; tune the set to a low power community station on band II VHF (FM), or a foreign station on low or medium frequency (MW/LW) – don’t worry if you don’t understand the language.
walk around your building; especially where your AV equipment is set up; and/or where there are any kinds of computers or electronic equipment with plug top power supplies. Listen carefully; and you will hear many places where the radio signal is swamped by “ssssssss” noise; or even rhythmic sounding pulses of noise that coincide with something like a computer mouse being moved or hard drive access.
If you hear this on LF/MF; it is the sort of interference that very easily finds it way into audio installations unless you use decent cable; balanced audio if possible and sometimes transformers; and avoid connecting the shield of two pair cable to signal ground at more than one point.
At VHF; its more of a simple nuisance factor if you happen to enjoy the radio programme being broadcast; in which case move the radio elsewhere [the top of the PC case is not a good place!] and/or use extension audio cables; or set up an external or loft antenna.
This might sound like all old fashioned stuff; but by doing this you “get the ear” for where interference comes from and what equipment might cause it; and learn useful ways of making all your productions sound better raaa
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