Wikipedia:Reference desk/Archives/Miscellaneous/2015 August 10

= August 10 =

Free Radio Frequency.
Hi All,

I have been working on a project of Radio frequency and their allocation to various countries, can anyone tell me if there is any radio frequency which someone can use it for free and same frequency can be used around the world or not? any information or link to info would be a great help.. thanks in advance Seekhle (talk) 12:59, 10 August 2015 (UTC)


 * ISM band.--Phil Holmes (talk) 13:07, 10 August 2015 (UTC)


 * Note that it's typically some combo of power and frequency that the law worries about. That is, some power level will probably be illegal, no matter what frequency you choose, but at some frequencies more broadcast power is permitted than at others. StuRat (talk) 18:46, 10 August 2015 (UTC)


 * Most countries agree for slices of bandwidth across the spectrum to be reserved for Amateur_radio_frequency_allocations. Uses must be non-commercial, and may require license for certain powers, but they should be otherwise free to use in many places around the world. There are some differences in which specific bands are considered open for amateur use in different countries. With some careful reading of the article and refs therein, I think you can find some bands that are freely usable almost everywhere. SemanticMantis (talk) 18:50, 10 August 2015 (UTC)

thanks for the response guys.. but is there someone who can give me specific answers please.Seekhle (talk) 09:37, 11 August 2015 (UTC)
 * Frequencies under 9kHz are usually free, as it it too expensive to make transmitters for this. Also the submillimeter waves over 300 GHz are likely to be unused. But can you use it? It will depend on local laws, and whether equipment can be manufactured. The ISM bands are documented in a table there, but the most popular is 2.4 to 2.5 GHz. Others include 13.553 MHz to 13.567 MHz and  26.957 MHz to 27.283 MHz. Graeme Bartlett (talk) 11:35, 11 August 2015 (UTC)

Thanks Graeme bartlett, which frequency i can use in "europe" for my large scale usage for free or minimal charge?if there are any..thanks in advance cheersSeekhle (talk) 12:55, 11 August 2015 (UTC)


 * What power level do you require ? StuRat (talk) 16:17, 11 August 2015 (UTC)
 * Region 1 includes Europe. And what is your application? What range do you need to send your waves. Do you need to send information, and if so what rate? And what is your toleration to interferences or outages? Graeme Bartlett (talk) 22:33, 11 August 2015 (UTC)

sorry for the late response.all the above parameters which can be ideal to GPS device..thanks greame and sturat in advance..Seekhle (talk) 06:17, 14 August 2015 (UTC)
 * GPS already has defined frequencies. But I suppose if you want to build your own system it is possible. However if you want to transmit from satellites, you really want as little interference as possible.  Also those extremely high frequencies will be absorbed in the atmosphere. If you really have enough money to launch a satellite why are you asking here? You will need to reserve and license a frequency slot in one of the navigation bands instead. Graeme Bartlett (talk) 13:17, 14 August 2015 (UTC)

bronze horseman weird photo
why does the monument look so small in, especially the pedestal? In the photo it appears as though it was hardly 3-5 m (10-16 ft) long, whereas in reality it's about 13 m (42 ft.) The picture is almost claustrophobic. Other photos look "normal." Is it because of perspective compression (great distance to object+high zoom)? Asmrulz (talk) 15:47, 10 August 2015 (UTC)


 * I think it's mainly because the camera was positioned about 15 feet above the ground. Our unconscious size-estimation tends to assume that the viewpoint is at ordinary eye level, unless there is evidence to the contrary. Looie496 (talk) 16:07, 10 August 2015 (UTC)


 * Agreed. The only size references are the people behind it and how the bushes are trimmed.  Of course, the people and bushes could be far away, but you can tell they are not by their focus and color.  Remove those, and there's no clue as to the scale. StuRat (talk)  18:44, 10 August 2015 (UTC)


 * Using the people as a rough scale, it's clear the base is at least 30-35 feet long. To do it right, though, someone would need to be standing next to or just in front of the base. ←Baseball Bugs What's up, Doc? carrots→ 20:14, 10 August 2015 (UTC)


 * Obviously this is a monument to Norma Desmond: "I am big. It's the picture that got small." Clarityfiend (talk) 02:24, 12 August 2015 (UTC)
 * :) Asmrulz (talk) 15:41, 12 August 2015 (UTC)