Radio

I Have an iPod Touch and I have downloaded the application A+ Police Radio Free, and it allows me to listen to police radios in different countries like New Zealand and the U.S.A., and also Australia. It let’s me listen in four Australian States, Queensland, South Australia, Western Australia and New South Wales. I don’t want to get caught listening to this if it’s illegal, so could you please help me?

It really depends on your local laws. Some places it is totally legal, others totally illegal, other fine at home, but not in your car or outside your home.

When were radios invented?
Who invented radios?
What are their significance?
Did they help in WW1 and WW2, if so, how?

Please can you try to answer some of these questions,
I can’t find any helpful websites to find these answers.
If you do come across any good websites about radio and why it is significant then can you put it in your ’sources’ box!
Thank-you in advance
Bea x

The original radio was called the ‘wireless telegraph’ and was used to send messages with dots and dashes, just like Samuel Morse’s device. An Italian named Gueliemo Marconi is/was usually credited with the invention of the radio/wireless telegraph, but he was sued for stealing Nikola Tesla’s work, and had to pay millions of dollars of damages to Tesla.

http://inventors.about.com/od/rstartinventions/a/radio.htm

Later, voice and music was sent over radio, and that was a huge leap in entertainment technology, and, of course, military technology. Radio is the basis of both RADAR and something called the ‘proximity fuse’ which helped win WW II.

I have a few GP340 UHF Motorola Two-Way radios, which need to be licensed before I can legally use them. I have not yet tried the programming software, but…

Can I set the frequency channels to the PMR channels in the range of: 446.103125 MHz to 446.196875 MHz (UHF)
The power output to: 4W

and legally use the radios without license in the UK?

or not even lower the power? Please advise.

Thanks.

In the UK, you are not allowed to operate any radio on the PMR frequencies over 500 milliwatts. As the minimum power on these radios is 1 watt, you are not supposed to use the PMR frequencies. However, the programming software does allow you to do so.

Nick

I frequently listen to internet radio. This can be linked up by audio sender from the dining room computer to the aux socket on the lounge HiFi, and could also possibly be heard elsewhere in the house by purchasing dedicated internet radio receivers utilising our wireless broadband connection.
It would therfore appear to be far more cost effective and less restricting if this signal could instead be transmitted via FM in some way to my existing portable radios. Is it possible to utilise and adapt the new MP3/FM car transmitters for this purpose, or is there some other simple means of achieving this?

yes fm wireless transmitter… up to 50-60 yards it works adjustable fm transmitter from 88.0 to 107.0

a capacitor is frequently placed across a 110V line to reduce the noise in radios.what is the smallest voltage such a capacitor should have?

110 VAC is the rms voltage that is an effective equivalent to 110VDC.

The 110 VAC voltage actually gets to a higher peak voltage of

1.414 x 110 = 155.54 volts peak

These higher peak voltages although brief in duration can damage a capacitors dielectric insulation if the peak voltage exceeds the working voltage of the cap

You could also add a safety factor of at least 10%(or more) so a cap rated no less than 175 would be required. Higher voltage rated caps (200v for example) would work and provide an added measure of safety

If I did get into Morse code, I would want to purchase a small, portable radio to send messages. Portability, for me, would be huge if it were possible to find a portable radio.

Also, how small do these radios typically get? Is it possible to get something as small as a walkee-talkee?

Radios which do morse code can be very small! Personally, I built one and put it in an Altoids tin. I probably could have fit it in something smaller even but you can’t beat the price and they’re everywhere. It’s a 30m rock-mite transceiver and transmits half a watt. It was only $29 from smallwonderlabs.com. Another interesting tiny morse transceiver is the ATS-3b, which has a VFO, operates on 6 bands and up to 4 watts and will still fit in an Altoids tin!

cn someone give the whole science behind it? how did they develop it? how did they know they could transfer signals through wires..how did they know to convert signals to transmissions? how do they use satelites and frequency in radios? etc etc…
well the 1st answer doesnt help at all…..

That would take half a day to answer so I will refer you to a couple useful links through wikipedia.

In short, the discovery of electricity led to the study of it for any purpose imaginable from communications to physical therapy to mechanics. The telegraph would transmit electrical pulses (long and short) over a conductive wire and an alphabet of dashes and dots was created to utilize this means of communications.

Radio was discovered by combining electric and magnetic waves of energy to produce an electromagnetic signal that could be tuned to transmit or receive different frequencies.

Telegraph
http://en.wikipedia.org/wiki/Electrical_telegraph

Radio
http://en.wikipedia.org/wiki/Radio

P.S. If you really want to learn about the mechanics of radio technology I suggest building one. I made one when I was younger and it was a good experience, but I believe they sell radio building kits now so it shouldn’t be as difficult gathering up all the materials.

I get one heck of an interference on my TV from the local taxis as they use their radios (i live next to a main road).

Pleas help it is driving me NUTS!!!! thanks!
I can actually hear what they say and where they are going whilst the TV goes into white noise.
Thanks for your answers, but i DO use Digital TV, though with an indoor aerial.

Hiya !

One solution would be to use a couple of ferrite rings in your aerial lead – something like these from Maplin Electronics…

http://www.maplin.co.uk/Search.aspx?criteria=ferrite ring&source=15

If you want more details – drop me an email

bought yesterday. Neither will work on batteries. The batteries are brand new and ive tested them with a battery tester and the battery tester is brand new. The batteries are duracell they say 9v2 on the package. The radios say they take one 9v battery. I dont know whats wrong.

The clock should still work on batteries, or maybe the batteries only act as a backup, so that when AC power is restored your clock is still set. Your cd player however will not work simply on a 9v battery.

what are these kinds of radios, perhaps where could I buy one?

THANKS

The units are called "Scanners".
I don’t know where you live but in canada most of the police services have moved from using regular communications systems to a newer system known as "Trunking". You will need to by a trunk tracker scanner in order to listen to what they are saying. These scanners are a bit more difficult to program than the older type because not only do you need to program the frequency the police are using, you also have to program a 4 digit code for the division you want to listen to.
If you live in an area where the cops have not moved to a trunking system then you can use a conventional scanner and listen to cops, fire, ambulance, cordless phone calls,
ham radio, and much more. You can buy either type of these scanners at several electronics stores like "Radio Shack"
"The Source In Canada" as well as stores that sell communications equipment like ham and cb radios. There are several brands but I like the "Uniden" units. You can get handheld battery operated models or one’s for mobile or home base use. If you choose a mobile or home model then there are several types of antennas you can choose from. just make sure you get an antenna that is made for the frequncies you want to listen to. If you want to save some cash you will find tons of scanners for sale on "Ebay".

Take care.