Amateur Radio

Making Airfix models.

800MHz is a commercial band. The closest ham bands to it are from 902MHz to 928MHz.

No. Not only is it illegal to amplify a CB radio beyond the FCC permitted four watts, but stereo amplifiers and linear amplifiers work in very different ways.

Orthogonal FDM is a method of passing digital data that uses multiple carriers. The basic idea is, you take a high-rate data stream, convert it into a number of low-rate data streams, put each of these streams on a slightly different frequency and dissemble all of it back into the high-rate stream at the distant end. A low-rate stream doesn't require as much bandwidth as a high-rate one does, so you can afford to use multiple frequencies without knocking everyone else off the air. Error correction schema are used to prevent losing data, and monitoring the atmosphere allows the radio to move channels around as necessary to ensure reliability. The reason you want to go through all this trouble is to be able to communicate when atmospherics turn bad. A similar technique is used in tropospheric-scatter radios, which bounce radio waves off part of the upper atmosphere; because the troposphere changes all the time, the only way to reliably communicate via it is to transmit the same data over several different frequencies at once. But in troposcatter, it's called diversity operation.

Minimum-shift keying is a form of frequency-shift keying, in which one frequency stands for a 1 - or 'mark' in teleprinter terms - and a different frequency for a 0, or space. This is a technique that's over a century old, and a century ago the way you did it was to wire a small capacitor in series with the contacts on an electromechanical relay, wire that assembly in parallel with the frequency-determining capacitor in your transmitter, and wire the relay's coil to your teleprinter. When the system needed to send a mark, the teleprinter closed the relay which changed the total capacitance of the LC tank which caused the radio's transmitting frequency to change. And they did it this way for at least seventy years! The problem with it (besides needing all those mechanical parts to get the thing to work, and the slow transmitting speeds it required; you certainly wouldn't be able to watch YouTube videos on your phone by keying an oscillator with a relay) is the technique created huge, bandwidth-eating sidebands that didn't matter when the only people sending FSK data were police departments and newspapers, but these days the only people NOT sending FSK data are babies too young to use phones, your grandma who refuses to buy a cell phone, and people in prison who aren't allowed to own cell phones. Today you couldn't get away with eating this much bandwidth, so "minimum-shift keying" - an FSK technique that creates very small sidebands - is the way to go, and feeding the signal through a gaussian filter to create gaussian MSK gives you a very reliable way to transmit data.

A good answer to put on your paper might be "OFDM uses multiple carriers and GMSK uses a single carrier."

Radio Radiorson

Radio Radiorson

Okay Whatever Here is the answer:

Marconi is sometimes given credit and considered the "Father of Radio". It was Nikola Tesla who invented the radio in 1891.

http://wireless.fcc.gov/services/index.htm?job=cft&id=amateur&page=cft_renew_amateur

Go to that site, and I suggest that you use the ULS. Your FRN will be in the ULS under your callsign, or on your license. 73's.

A cycle per second is a Hertz, abbreviated Hz. Therefore, a billion cycles per second (assuming an American, or "short scale", billion) is a Gigahertz (GHz).

The 10-meter band is a portion of the shortwave radio spectrum internationally allocated to amateur radio and amateur satellite use on a primary basis. The band consists of frequencies stretching from 28.000 to 29.700 MHz

There is some evidence that amateur SWL operators (receiving only) intercepted NASA communications dealing with Astronauts sighting UFO"s from space craft. The once-popular Ham radio magazines (on the general newstand market) plugged upcoming space shots with some gusto in the late sixties- (Apollo the ultimate DX ( distance reception)) was a frequent cover story with a picture of a space capsule.The subject occasionally flares up in UFO publications, rarely seen on the newstands or magazine stores.

Nobody is really sure, not even the authorities and old-timers in the hobby itself.

The formal designation for that service is "Amateur Radio".

One theory is that H.A.M. is an acronym paying homage to three great radio pioneers:

Heinrich Hertz (demonstrated existence of electromagnetic waves),

Edwin Armstrong (invented modern FM radio), and

Guglielmo Marconi (developed wireless telegraphy).

Another theory is when the first amateur radio operators where using CW (Morse Code), that they tended to have a "heavy" (hard) hand, and was called being "ham fisted". This tends to be the most common theory, by the ARRL. (KC0KM)

Squealing can come from a number of things. But usually, its a bad ground connection from the radio or either the antenna needs a better ground.

That is a matter of opinion. It depends on the style someone likes.

Well, it depends on 2+1 things:

The first two things are:

Age

Condition

The last (+1) is the human factor; how much is somebody willing to pay for it.

I have received a grundig for free, bought one for $75, and have seen them on eBay for over $600 and $1000. Although I don't believe they are worth more than $150-$200 , it still depends on your condition and what somebody wants it for.

If you are offered $100 consider it sold.

If you are offered $200 consider yourself lucky.

If you are offered more than $300 consider the buyer a sucker.

The "money" is in OLD (1920-1940) AM radio. Grundig is just not that old yet.

There are three classifications (Technician, General, and Extra) of ham radio operators. Depending upon the band or frequency they are operating on and license class, some bands only allow 25 to 100 watts of power. The maximum power that a ham can operate with is 1500 watts. This is controlled by the FCC. The FCC website has all the information about which bands and licenses are necessary.

In addition to garden variety AM (double sideband, full carrier), Single Sideband may be used on CB, with full, reduced, or suppressed carrier.

The purpose of these variations is to reduce interference on the CB channels, which have been jam-packed since the the 27 MHz Citizens Band was created almost 60 years ago.

No. The only emission mode allowed to CB is AM voice.

mint 1ooo

http://riverside.ca.scanamerica.us/index.php There ya go!

Channel 1 is not programmed

It means to see if you can communicate direct or by relay with someone.

Prefixes assigned to the Republic of India: -- ATA to AWZ

-- 8TA to 8WZ

-- VTA to VWZ

Just bought one of these last week and was frustrated by the lack of a wiring diagram, so I posted one to my blog: http://www.portecho.net/?p=373. It's easier to show with a diagram than explain in words, so I recommend checking out that image.

Basically, with the wiring terminals facing up, the front row (closest to the shaft) is the right channel and the back row is the left. Using the same orientation, the right-most terminal is for your grounds, the middle is input, and the left is output. Don't forget to wire input and output grounds together.

So, strip your input and output wires, solder the red wires to the right and white/black to the left and copper to the ground. Hope that helped.

When two frequencies are "mixed" the sum and the difference frequencies are produced. These frequencies are called heterodynes. If these frequencies are outside the range of human hearing they are said to be supersonic. The full name of a superhet receiver is supersonic heterodyne. This receiver uses a mixer to produce an intermediate frequency outside the range of human hearing.

Before superhets were in common use, but following from the old crystal set was an amplified form of the crystal set, called the 'Tuned Radio Frequency" receiver, or "TRF" for short. With many TRF receivers, a control called 'regeneration' controlled the gain of the RF amplifier, and could be turned up to the point that the entire radio set became unstable and oscillated, usually at the frequency you were tuned to. With the gain set just below the point of oscillation, these receivers were very sensitive. For listening to morse code signals, the control would be advanced just into the oscillation stage, and the difference in frequency between the received signal and the receiver's oscillation became a 'beat note', or a beeping sound, that was easy to receive in noisy conditions.

This form of reception became known as 'heterodyne reception', and this type of radio was called a 'regenerative receiver'.

Problem was, this operation usually required 3 hands, a still room and a lot of patience. Once tuned, the radio would drift in frequency, or burst into loud screaming oscillation, seemingly for no apparent reason. Sometime later, the 'super-regenerative' receiver was developed in an effort to simplify operation and these were used up into VHF frequencies into the early '30's.

Eventually, with the development of better radio tubes and more elaborate design, the suphet rapidly became the most popular, as it was so easy to use. At last, you only needed one hand to operate a radio. And you could walk away and come back and it was still tuned to the station. This was the '30's where radios found their way into every westerner's living room, bringing news and entertainment to the masses (that could afford it). By the 60's, we all had 'transistors', and the superhet was everywhere. Now, most of us have TV, cable or satellite. And you know which process they all still use to turn the RF signal into a video signal that the screen can display?

Just testing!