THE POSTCARD CROSSING PROJECT

From Holand

Walkie Talkie Two Way Radios

Walkie talkie two way radios have been around since Motorola built a large, cumbersome hand-held portable two-way radio for US soldiers to use during World War II.
The original military walkie talkie was a breakthrough for its day, because it meant that any soldier could pick it up and use it, and unlike other military radios, this one could be carried easily. The batteries were built-in, and the telescopic antenna could easily be collapsed for transport. So it was very quick to get the radio set going, and it could be operated just about anywhere – even while a soldier was walking. And that’s where the nickname ‘walkie talkie’ came into being.
That first handheld US Army walkie talkie had only one channel, and despite its chunky size and low power transmission strength, it was powered by valves – as all radio equipment was back in those days. The transistor had already been discovered back then but wouldn’t go into production for several more years.
By the 1960s transistors were becoming commonplace and simple silicon chips were coming into use as well. This was a perfect time to introduce walkie talkie CB radios to the American public. These low-powered CB radios were licensed by the FCC as Part-15 radio appliances.
These 27 MHz walkie talkie two way radios were limited to a few hundred milliwatts of power, and by law they could only have a small antenna. This meant they could only be used over short distances, but they proved to be very popular nonetheless.
For the first time, these small cheap 27 Mhz handheld CB radio transceivers could be carried by campers, hunters, fishermen and other sportsmen and hobbyists.
Soon they would be replaced by VHF and even UHF two-way radios, which also worked mostly line-of-sight but had an FM signal for better sound clarity. FM became the normal mode for business radios and for police and public service band radios in mobile, base and handheld walkie talkies as well.

What is the difference between CB Radio and Ham Radio?

Many people think CB Radio and Ham Radio (that's licensed, trained Amateur Radio operators) are one and the same thing. There are some similarities, yes, but the differences are like chalk and cheese.

CB or the Citizens Band Radio Service is where the FCC allows untrained and unlicensed individuals to use low-powered two-way radios radios for personal or business use.CB radios are limited to a power output of 5 Watts AM or 12 Watts PEP (in single sideband/SSB mode). These 2 way radios operate in the 27 MHz HF (shortwave) band, and people using them are only permitted to talk to others within the United States. No overseas (DX) contacts are allowed. The CB radio service has 40 channels assigned to it. Since each channel can be used in AM mode or as USB (upper sideband) or LSB (lower sideband) in single-sideband mode, some folks like to imagine they have 80 or 120 channels. But that's not quite right.

Single sideband transceivers (SSB two-way radios) cost more than AM transceivers because they use more complex circuitry, and they take a little more skill to operate properly. In return, the SSB radio signals will almost always 'get through' over longer distances, and in poorer atmospheric conditions than an AM signal can manage.

Ham Radio (officially called the Amateur Radio Service) is where people who have studied two-way radios, antennas and US and international regulations - and who have passed an examination (and paid a fee) are allowed to communicate with other radio hams in their own country and with other licensed radio hams around the world.Ham Radios (Amateur Radio equipment) can range in power from less than 1 Watt to 1000 Watts, and it isn't the equipment that gets licensed... It is the person operating it.

Most handheld ham radios would be 5 Watts or less, but mobiles are usually between 10 and 100 Watts, most HF amateur radio base stations are 100 or 200 Watts, and hams are allowed to use linear amplifiers that give them up to 1000 or 2000 Watts of power.On top of this, Amateur Radio Operators (Hams) are permitted to use large antennas on towers that may be 30 feet, 50 feet or higher in the air, plus all kinds of fancy sophisticated antenna systems to send out a highly directional transmitter beam. Like yagi or quad antennas.Why do radio Hams have all these privileges that CBers do not? It comes back to the licensing and the expertise that Hams/Amateur Radio Operators study for.

They are supposed to have the skills to set up and operate their two-way radio hobby, and to do it without causing any radio interference to their neighbors or to other radio users.Amateur Radio operators also have to know how to handle emergency radio traffic, which is admittedly quite rare. (It seems to happen much more in the movies.) Licensed Hams are taught not to interfere if distress traffic is taking place. One takes control, and the others know to shut up and just listen. But that is another subject.

Visit:

http://www.squidoo.com/CB-Radio-and-Ham-Radio