Kchibo DSP Full Wave Band Handheld Portable Satellite Radio D680

Specifications:

• Frequency Range: FM 64-108 MHz; AM 522 - 1710 KHz (9k tuning step); SW 2.30 - 21.85 MHz
• Memory Preset: 90, FM , AM and SW ( 30 x 3)
• Noise Limit Sensitivity: FM better than 3.5uV, MW better than 3mV/m, SW better than 32uV
• Single Signal Selectivity: >40dB
• SNR: FM >= 45dBu; AM > = 40dBu; SW >= 40dBu
• Power: DC 3V 300mA or 2 x AA batteries (not included)
• Maximum Current Consumption: <200mA
• MPO: ≥100mW
• Stereo Reception Separation: >=20dB 
• Speaker: 57mm/8ohm/0.5W
• Earphone Jack: 3.5mm 32ohm
• Size: 121 x 74 x 25mm / 4.76 x 2.91 x 0.98in(L x W x H)

Features:

• AM/FM/SW radio
• FM stereo
• This full wave band radio adopts advanced SDR technology
• Imported high quality DSP processor
• Build in high speed MCU circuit
• Signal strength indication
• Four searching modes
• Manual scan
• Auto scan
• 90 memory presets
• Tuning knob
• 40 levels electronic volume control
• Wake-to-radio
• Perpetual calendar
• Sleep function
• Telescoping antenna
• The full wave band radio is with built-in speaker
• Standard earphone jack 

Details:

• Advanced DSP digital tuning AM/FM/SW pocket radio receiver

• The full wave band radio offers manual, auto tuning and 90 memory presets

Size in Detail:

How Does FM Radio Work?

Sound Waves and Frequency:

• All sound energy is in the form of a wave. The frequency of a wave is the measurement of the number of cycles that it undergoes in a given time frame. Hertz is a measurement of frequency that depicts the number of wave cycles per second. FM signals are measured in megahertz so an FM signal of 97.5 relates to 97,500,000 waves/second

Frequency Modulation:

• FM actually stands for Frequency Modulation. FM signals use various frequency levels that reproduce the sound of the originating source (i.e. music). You've probably noticed that FM contains all your music channels while AM radio is limited to news and talk programming. This is because frequency modulation allows for the transmission of the greater range of frequencies (high and low sounds) contained within music.

Transmission:

• FM radio originates at the broadcast source (radio stations). These stations use large antennas to send out their broadcast signal. Electrical charges are pushed up and down the broadcast antenna at a rate that relates to the carrier frequency. The movement of electrical charges creates an electromagnetic field which sends out
• electromagnetic waves. The waves are sent in all directions. Carrier waves are sent out at a frequency that can be detected by your antenna (the radio station number). They carry sound information that includes the different frequencies of the original broadcast

Reception:

• The electromagnetic carrier wave travels through the atmosphere until it is picked up by a receiver antenna (i.e. your car radio antenna). At this time the wave causes electrical charges to be pushed up and down your antenna and on into your receiver. The receiver decodes the modulated frequency information and then passes it to the speakers

Processing and Hearing:

• The speaker vibrates according to the processed frequencies and pushes air molecules that recreate the original sound waves and pass them to your ears. You hear the music or talk that was sent in the original broadcast. Since electricity works at the speed of light, this process, from broadcast to listener, is instantaneous

Loss of Signal:

• You've probably noticed, particularly if you listen to FM radio in the car, that eventually you will lose your signal. The simple reason for this is that the short wavelength of FM radio waves cause them to travel in straight lines. The earth, however, is curved. Therefore, as the earth curves, FM waves continue in a straight line into the atmosphere and are no longer receptible. The short waves are also affected by obstacles like mountains

How to Build an FM Radio?

• A radio provides signal transmission via the use of electromagnetic waves. The frequencies a radio uses are lower than those of visible light. A German scientist by the name of Heinrich Hertz was the first to detect and product radio frequencies, in 1888. Radios are still in wide use, even in this internet age.Building a simple FM radio only requires a small amount of time and materials. Although this radio is fully functioning, it isn't very pretty

Instructions:

• Solder the ferrite loop to the variable capacitor. Only solder the ferrite wire that is painted black. Make sure you are soldering the ferrite loop to the center lead of the variable capacitor
• Solder the unpainted wire of the ferrite loop to the variable capacitor's right lead
• Solder the germanium diode to the same right lead of the variable capacitor as the unpainted wire of the ferrite loop. Only connect one end of the germanium diode
• Solder one end of the piezoelectric wire to the other (free) end of the germanium diode
• Solder the other end of the piezoelectric wire to the variable capacitor's center lead
• Take note of the red-painted wire of the ferrite coil. Use an alligator clip to attach it to the antenna wire
• Use the remaining alligator clip lead to attach the green-painted wire of the ferrite coil to a good ground. You can use a cold water pipe for the ground

Package Included:

• 1 x Portable Satellite Radio
• 1 x Earphone
• 1 x User Manual