IC-746Pro_review_ARRL_2002.pdf

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1、ARRL Laboratory Expanded Test-Result Report ICOM IC-746 Pro Prepared by: American Radio Relay League, Inc. Technical Department Laboratory 225 Main St. Newington, CT 06111 Telephone: (860) 594-0214 Internet: mtracyarrl.org Order From: American Radio Relay League, Inc. Technical Department Secretary

2、225 Main St. Newington, CT 06111 Telephone: (860) 594-0278 Internet: reprintsarrl.org Price: $7.50 for ARRL Members, $12.50 for non-Members, postpaid. Model Information: IC-746 Pro Serial #: 01484 QST Product Review May, 2002 Manufacturer: ICOM America 2380 116th Ave NE PO Box C-90029 Bellevue, WA 9

3、8004 Telephone: 425-454-8155 ARRL Laboratory Expanded Test-Result Report Model: ICOM IC-746 Pro Serial: 01484 Copyright 2002, American Radio Relay League, Inc. All Rights Reserved. Page 1 Downloaded by? Amateur Radio Directory? ? www.hamdirectory.info Table of Contents: Introduction.3 Transmitter Ou

4、tput Power.4 Transmitter Output Power Results.5 Current Consumption.5 Transmit Frequency Range.6 CW Transmit Frequency Accuracy.6 Spectral Purity.7 Spectral-Purity Graphs.8 Transmit Two-Tone IMD.11 Transmit IMD Graphs.12 SSB Carrier and Unwanted Sideband Suppression.15 CW Keying Waveforms and Sideba

5、nds.15 Keying Waveforms .16 Keying Sideband Plots.16 CW Keyer Speed Range.19 Keyer Sidetone Frequency.19 Transmit/Receive Turnaround Time.19 Transmit Delay Time.19 Transmit Composite Noise.20 Transmit Composite Noise Graphs.20 Receiver Noise Floor .21 Receive Frequency Range.22 AM Sensitivity.23 FM

6、SINAD.23 Antenna Port Isolation .24 Blocking Dynamic Range.24 Two-Tone 3rd-Order IMD Dynamic Range.26 Third-Order Intercept.27 Swept Dynamic Range Graphs.28 Second-Order Intercept.30 In-Band Receiver IMD.30 FM Adjacent Channel Selectivity.31 FM Two-Tone 3rd-Order Dynamic Range.32 IF and Image Reject

7、ion.32 Audio Output Power .33 Audio Hiss.33 IF and Audio Frequency Response.33 Squelch Sensitivity.34 S-Meter Sensitivity .34 ARRL Laboratory Expanded Test-Result Report Model: ICOM IC-746 Pro Serial: 01484 Copyright 2002, American Radio Relay League, Inc. All Rights Reserved. Page 2 Introduction Th

8、is document summarizes the extensive battery of tests performed by the ARRL Laboratory for each unit that is featured in QST Product Review. For all tests, there is a discussion of the test and test method used in ARRL Laboratory testing. For most tests, critical conditions are listed to enable othe

9、r engineers to duplicate our methods. For some of the tests, a block diagram of the test setup is included. The ARRL Laboratory has a document, the ARRL Laboratory Test Procedures Manual, that explains our specific test methods in detail. While this is not available as a regular ARRL publication, it

10、 may be downloaded from our web page. Most of the tests used in ARRL product testing are derived from recognized standards and test methods. Other tests have been developed by the ARRL Lab. The ARRL Laboratory test equipment is calibrated annually, with traceability to National Institute of Standard

11、s and Technology (NIST). The units being tested are operated as specified by the equipment manufacturer. Equipment that can be operated from 13.8 volts (nominal) is also tested for function, output power and frequency accuracy at the minimum specified voltage, or 11.5 volts if not specified. Also, u

12、nits that are capable of mobile or portable operation are tested at their rated temperature range, or at 10 to +60 degrees Celsius in a commercial temperature chamber. ARRL Product Review testing represents a sample of only one unit (although we sometimes obtain an extra sample or two for comparison

13、 purposes). This is not necessarily representative of all units of the same model number. It is not uncommon that some parameters will vary significantly from unit to unit. The ARRL Laboratory and Product Review editor work with manufacturers to resolve any deviation from specifications or other pro

14、blems encountered in the review process. These problems are documented in the Product Review. ARRL Laboratory Expanded Test-Result Report Model: ICOM IC-746 Pro Serial: 01484 Copyright 2002, American Radio Relay League, Inc. All Rights Reserved. Page 3 Transmitter Output Power Test description: One

15、of the first things an amateur wants to know about a transmitter or transceiver is its RF output power. The ARRL Lab measures the CW output power for every band on which a transmitter can operate. The equipment is also tested on one or more bands for any other mode of operation for which the transmi

16、tter is capable. Another purpose of the Transmitter Output-Power Test is to measure the dc current consumption at the manufacturers specified dc-supply voltage, if applicable. Many transmitters are de-rated from maximum output power on full-carrier AM and FM modes. In most cases, a 100-watt CW/SSB t

17、ransmitter may be rated at 25 watts carrier power on AM. The radio may actually deliver 100 watts PEP in AM or FM but is not specified to deliver that power level for any period of time. In almost all cases, the linearity of a transmitter decreases as output power increases. A transmitter rated at 1

18、00 watts PEP on single sideband may actually be able to deliver more power, but as the power is increased beyond the rated RF output power, adjacent channel splatter (IMD) usually increases dramatically. Key Test Conditions: Termination: 50 ohms resistive, or as specified by the manufacturer. Block

19、Diagram: CAUTION!: Power must only be applied to the attenuator input! Do not reverse input and output terminals of the Bird 8329. RF Power Attenuator minimum power showed 0 segments lit. 2. The unit showed LED segments reaching a fixed display label reading 100 at full power. Current Consumption (D

20、C-powered units only) Test Description: Current consumption can be important to the success of mobile and portable operation. The ARRL Lab tests the current consumption of all equipment that can be operated from a battery or 12-14 vdc source. The equipment is tested in transmit at maximum output pow

21、er. On receive, it is tested at maximum volume, with no input signal, using the receivers broadband noise. Current Consumption: Voltage Transmit Current Output Power Receive Current Lights? Notes 13.8 V 19.8 A 110.7 W 1.9 A ON ARRL Laboratory Expanded Test-Result Report Model: ICOM IC-746 Pro Serial

22、: 01484 Copyright 2002, American Radio Relay League, Inc. All Rights Reserved. Page 5 Transmit Frequency Range Test Description: Many transmitters can transmit outside the amateur bands, either intentionally, to accommodate MARS operation, for example, or unintentionally as the result of the design

23、and internal software. The ARRL Lab tests the transmit frequency range inside the screen room. Most modern synthesized transmitters are capable of operation outside the ham bands, but spectral purity is not always legal outside the bands, so caution must be used. In addition, most other radio servic

24、es require that transmitting equipment be type accepted for that service. Amateur equipment is not legal for use on other than amateur and MARS frequencies. Test Results: Frequency Low-Frequency Limit High-Frequency Limit Notes 160 M 1.800 000 MHz 1.999 999 MHz 80 M 3.500 000 MHz 3.999 999 MHz 40 M

25、7.000 000 MHz 7.300 000 MHz 30 M 10.100 000 MHz 10.150 000 MHz 20 M 14.000 000 MHz 14.350 000 MHz 17 M 18.068 000 MHz 18.168 000 MHz 15 M 21.000 000 MHz 21.450 000 MHz 12 M 24.890 000 MHz 24.990 000 MHz 10 M 28.000 000 MHz 29.700 000 MHz 6 M 50.000 000 MHz 54.000 000 MHz 2 M 144.000 000 MHz 148.000

26、000 MHz CW Transmit Frequency Accuracy Test Description: Most modern amateur equipment is surprisingly accurate in frequency. It is not uncommon to find equipment operating within a few Hz of the frequency indicated on the frequency display. However, some units, notably analog units, not using a pha

27、se-lock loop in the VFO design, can be off by a considerable amount. Frequency is also measured at minimum output power, low supply voltage (12 volt units only) and over the operating temperature range (mobile and portable units only). Non-portable equipment is not tested in the temperature chamber.

28、 Test Results: Unit Display Frequency Supply Voltage Temperature Measured Frequency Full Output Power Notes 14.000 000 MHz 13.8 V 25 C 13.999 995 MHz 50.000 000 MHz 13.8 V 25 C 49.999 980 MHz 144.000 000 MHz 13.8 V 25 C 143.999 948 MHz 1 Notes: 1. Measured frequency at low power output was 7 Hz lowe

29、r on 2M. ARRL Laboratory Expanded Test-Result Report Model: ICOM IC-746 Pro Serial: 01484 Copyright 2002, American Radio Relay League, Inc. All Rights Reserved. Page 6 Spectral Purity Test Description: All transmitters emit some signals outside their assigned frequency or frequency range. These sign

30、als are known as spurious emissions or spurs. Part 97 of the FCC rules and regulations specify the amount of spurious emissions that can be emitted by a transmitter operating in the Amateur Radio Service. The ARRL Laboratory uses a spectrum analyzer to measure the spurious emission on each band on w

31、hich a transmitter can operate. The transmitter is tested across the band and the worst-case spectral purity on each band is saved to a file on disk. Spectral purity is reported in dBc, meaning dB relative to the transmitted carrier. The graphs and tables indicate the relative level of any spurious

32、emissions from the transmitter. The lower that level, the better the transmitter is. So a transmitter whose spurious emissions are 60 dBc is spectrally cleaner than is one whose spurious emissions are 30 dBc. Key Test Conditions: Unit is operated at nominal supply voltage and temperature. Output pow

33、er is adjusted to full power on each amateur band. A second measurement is taken at minimum power to ensure that the spectral output is still legal at low power. The resolution bandwidth of the spectrum analyzer is 10 kHz on HF, 100 kHz on VHF, 1 MHz on UHF. Block Diagram: CAUTION!: Power must only be applied to the attenuator input! Do not reverse input and output terminals of the Bird 8329. RF Power Attenuator the receiver is operated in its linear region. Desired signal set to 10 dB below the 1-dB compression point, or 20 dB above the noise floor in receivers