Icom IC-R8500 Squelch function, Functions for FM, Functions for SSB/CW, Center indicator

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RECEIVE FUNCTIONS 4

■Squelch function

The IC-R8500 has 2 types of squelch, noise squelch and S-meter squelch.

Noise squelch: Only acts on noise; has good sensi- tivity. It can be adjusted for reception of weak signals. Strong signals exceeding a certain level will always cause the squelch to open.

S-meter squelch: S-meter squelch does not open for weak signals but can be adjusted to open for signals over a wide range of strengths. Once you have selected a threshold point in a range, the IC-R8500

Noise squelch threshold (not available in SSB, CW, WFM and

AM narrow modes)

S-meter squelch threshold

• Signals below the S-meter level are muted.

will open for all signals above this point.

To adjust the squelch, rotate [SQUELCH].

•Clockwise rotation closes the squelch (sets the threshold point higher); counterclockwise rotation opens the squelch (for reception of weak signals).

When [SQUELCH] is

S 1 3 5 7 9 +20dB +60dB

rotated past center,

the S-meter shows

 

the signal strength

SIGNAL

needed to open the

 

squelch.

 

■Functions for FM

DCenter indicator

FM signals have a wide bandwidth which makes them

 

easy to receive. However, you may be tuned off-cen-

RECV

ter resulting in audio distortion. The IC-R8500’s off-

 

center indicators appear in such cases, making it

 

easy to fine tune to the center of the frequency.

One of these indicators appears when the received

 

signal is off-center.

 

 

DAFC

AFC stands for automatic frequency control. The AFC circuit automatically compensates the tuning when a receive frequency drifts or goes off frequency.

When one of the off-center indicators appears, the IC-R8500 can adjust the receive frequency automat- ically—when the AFC function is turned ON and an off-center frequency is received, the frequency in the display automatically changes to reflect the center of the signal.

AFC

RECV

When one of these indicators appears, the displayed frequency is automatically moved to the center frequency.

■Functions for SSB/CW

DIF shift

The IF shift function electronically changes the cen- ter of the IF (intermediate frequency) passband fre- quency to reject interference. The IF shift is not avail- able in FM and AM modes.

➀Adjust the [SHIFT] control for a minimum interfer- ence signal level.

•The audio tone may be changed while the IF shift is in use.

➁Set the shift control to its center position when there is no interference.

APF IF SHIFT

APF IF SHIFT

APF IF SHIFT

Shifts low

Center

Shifts high

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Contents IC-r8500 Explicit Definitions Accessories included with the IC-R8500 QtyTable of Contents Panel Description ➋ SLEEP/SET Switch SLEEP/SETFront panel ➎ Headphone Jack Phones@0S-METER 5SPEECH/LOCK Switch SPCH/LOCK7MAIN Dial @7SCAN Switches Scan Scan SET Auto p Skip pPrio p DLY D/S pRear panel 9RECEIVE Indicator 7ATTENUATOR IndicatorsFunction display MHz kHzConnections Mounting installationLocation Receiver standRequired connections TYPE-N Connector Installation Example Using a long wire antenna for HF bandsPL-259 Connector Installation Example Antenna connection GroundingTape recorder connections Connecting to a PCTransceive function Data demodulation terminalUsing the keypad Frequency SettingExample Setting the Frequency Using the Keypad Read me firstSelecting a tuning step Using the main dialSetting the programmable tuning step Setting the lock function coverageReceive Functions Initial settingsMode selection Squelch function Center indicatorFunctions for FM Functions for SSB/CWNoise blanker BFO adjustmentAudio peak filter Dagc functionData communications For high speed data 9600 bps reception in FM modeConnections Receiving methodMemory Channels Bank Initial Contents UsageGeneral Bank selectionUsing the keypad Using the M-CH selectorChannel selection Bank limit functionClearing ProgrammingCopy and paste memory editing Bank name programming Channel/bank namesChannel name programming To rearrange bank channel assignments Assigning channel numbersDeleting memory channels ➃ Push Bank for 1 sec. to perform the selected operation Adding/inserting memory channels➂ Rotate M-CH to select the following Operation ScansMemory scan Memory select scanDProgrammed scan Specifying skip channel and frequency Mode select functionPriority scan Specifying skip channelsTurning OFF the automatic function Automatic bank limit/skip functionsVoice scan control function Programming scan edge frequencies Scan speed/delay functionsScan resume condition OFF DLY ∞Scan speed Assigning a function to the DELAY/SPEED controlScan delay Operation Sleep TimerSelecting quick set mode SET ModeSelecting initial set mode Display Example Quick SET ModeQuick set mode items Initial set mode items Installed, you can select between English When the optional UT-102 Voice Synthesizer Unit isInstalled, you can select between faster or slower This item sets the data transfer rate. When AutoRS-232C socket Remote jack Connector InformationIf OUT jack AGC OUT jackREC Remote jack DC 13.8 V and DC in socketsREC OUT jack Phones jackCommand table Control CommandsData format Basic format from PC to IC-R8500‘OK’ message from IC-R8500 to PC Memory channel contents set & write 1A‘NG’ message from IC-R8500 to PC Special bank number and channels bnMaintenance ➂Replace the top cover Optional InstallationsCR-293HIGH Stability Crystal Unit TV-R7100 specifications OperationGeneral TV receiverTroubleshooting Memory Channels Scan Problem Possible Cause Solution Receiver SpecificationsGeneral AH-7000 OptionsFL-52ACW Narrow Filter 455 kHz 500Hz/-6 dB AD-55/A/V AC AdapterCount on us

IC-R8500 specifications

The Icom IC-R8500 is a highly regarded general-purpose receiver that has made its mark among amateur radio enthusiasts and professionals alike. This versatile communication receiver is known for its wide frequency coverage, advanced features, and robust design, making it a valuable tool for various applications, including shortwave listening, public safety communication, and aircraft monitoring.

One of the standout features of the IC-R8500 is its extensive frequency coverage. It spans a range from 0.1 MHz to 3 GHz, allowing users to access a wide spectrum of signals. The receiver includes coverage of HF, VHF, UHF, and even microwave bands, making it suitable for listening to everything from amateur radio transmissions to satellite communications.

The receiver employs a high-performance double-conversion superheterodyne architecture, which contributes to its excellent sensitivity and selectivity. The advanced RF circuitry minimizes interference and enhances the clarity of received signals. Users can expect outstanding audio quality and a wide dynamic range, even in challenging reception conditions.

Digital Signal Processing (DSP) is another key technology incorporated into the IC-R8500. The DSP capabilities allow users to apply noise reduction and filtering techniques to improve the quality of the received audio. Features such as automatic notch filtering and IF filtering help eliminate unwanted noise, enhancing the listening experience.

The IC-R8500 is equipped with a large, easy-to-read LCD display that provides information on frequency, mode, signal strength, and other essential parameters. The user-friendly interface simplifies operation, allowing quick access to various settings and functions. Additionally, the receiver supports various modulation modes, including AM, FM, SSB, and CW, catering to different listening preferences.

For those seeking enhanced connectivity, the IC-R8500 offers multiple options, including an audio output jack, and external speaker connections. It also has a built-in memory function, allowing users to store and recall favorite frequencies easily. The receiver can be controlled via a computer interface, offering versatility for advanced users and programmers.

In summary, the Icom IC-R8500 stands out for its wide frequency range, superior sensitivity, and advanced features powered by DSP technology. Its robust construction and user-friendly design make it a favorite among communications enthusiasts seeking a reliable and versatile receiver for various applications. Whether for hobbyist listening or professional use, the IC-R8500 remains a top choice in the world of radio receivers.
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