JFZT76XWireless Microphone

Top, Mic Botto m View

Batter y Co mpartme nt Channel Controls Circuit Board, Bottom Circuit Board, Top

INTRODUCTION The following data are submitted in connection with this request for type certification of the ATW-T76X transmitter in accordance with Part 2, Subpart J of the FCC Rules. The ATW-T76X is a 3 milliwatt (ERP(d), UHF, frequency modulated, synthesized, battery operated transmitter configured as a hand-held microphone for wireless microphone applications under Part 74.

Subsection 2.983(d)(9): Factory Tune-up Procedure Test Equipment 1. BNC-P Coaxial RF cableAudio Technica custom RF cable 2. DC Power SupplyKenwood PR-18 3. Audio Signal GeneratorLeader LAG126 4. Modulation Meter (FM liner detector)Anritsu MS61A 5. Spectrum AnalyzerAdvantest R3261A 6. Pre amplifierAnritsu MH648A 7. OscilloscopeIwatsu SS-5705 8. DC Volt MeterAdvantest TR6845 9. AC Millivolt MeterNational VP9680A Adjustment of T76 circuit board 1. Connect the Audio, Control and RF circuit board of ATW-T76 and install it in to the PCB fixture. 2. Supply 9V from the DC power supply to the power supply terminal (CNP 6 and 7) of T76 3. Connect BNC-P coaxial RF cable with input connector of Spectrum analyzer. 4. Connect BNC-P coaxial RF cable to CNP3 terminal of T76 5. Set T76 to channel “50”. 6. Set the center frequency of Spectrum analyzer to oscillation frequency of T76, and set frequency span to 3.5GHz. 7. Set the power switch of T76 (SW1) to ST-BY position. Make sure to confirm that when turn the power on, power LED flash momentary. 8. Make sure that RF signal appears on Spectrum analyzer and no parasitic oscillation observed. 9. Adjust and set the VR4 where maximum RF output (10dBm +/- 3dB) as well as power supply current not exceed 50mA. 10. Adjust and set the VC2 where Maximum RF output could obtainable as well as spurious level could set minimum (less than 50dB). 11. Set frequency span of the Spectrum analyzer to 100KHz. 12. Set RF signal on the Spectrum analyzer to a desired Oscillating frequency by turning the VC1 onT76. 13. Gradually reduce power supply voltage from 9 V to 6.5V and make sure that Oscillating frequency stay same. 14. Check the power indicator LED start to lights when power supply voltage reached to 6.5V. 15. Set frequency span to “3.5GHz”. 16. Gradually move power supply voltage from 9 V to 6.5V and make sure that no parasitic oscillation observed. 17. Set the Power supply voltage back to 9V. 18. Remove the BNC-P coaxial RF cable from input connector of the Spectrum analyzer, and connect it to the Preamplifier. 19. Make sure that the Preamplifier and Modulation Meter (FM linear detector) are connected together. 20. Input –13.2dBV at 1kHz signal from the Audio signal generator to the Mic input of T76 by checking the level of the signal on AC milli voltmeter. 21. Set T76 to channel “50” and set the frequency range of the Modulation meter (FM linear detector) to the oscillation frequency of T76 22. Make sure that Oscilloscope has no irregular wave. Then, set the modulation levels appeared on the Modulation meter (FM linear detector) to +30KHz by turning VR3 on T76. 23. Set T76 to channel “00” and “99”. Make sure that Deviation of the each cannel stays same.

ENGINEERING STATEMENT For Type Certification of AUDIO-TECHNICA CORPORATION Model: ATW-T76X FCC ID: JFZT76X I am an Electronics Engineer, a principal in the firm of Hyak Laboratories, Inc., Springfield, Virginia. My education and experience are a matter of record with the Federal Communications Commission. Hyak Laboratories, Inc. has been retained by Audio-Technica US, Inc., to make type certification measurements on the ATW-T76X transmitter. These tests were made by me or under my supervision in our Springfield laboratory. Test data required by the FCC for type certification are included in this report. It is submitted that the above mentioned transmitter meets FCC requirements and type certification is requested. ______________________________ Rowland S. Johnson Dated: February 12, 2001 A. INTRODUCTION The following data are submitted in connection with this request for type certification of the ATW-T76X transmitter in accordance with Part 2, Subpart J of the FCC Rules. The ATW-T76X is a 3 milliwatt (ERP(d), UHF, frequency modulated, synthesized, battery operated transmitter configured as a hand-held microphone for wireless microphone applications under Part 74. B. GENERAL INFORMATION REQUIRED FOR TYPE CERTIFICATION (Paragraph 2.983 of the Rules) 1. Name of applicant: Audio Technica Corporation 2. Identification of equipment: FCC ID: JFZT76X a. The equipment identification label is included as a separate exhibit. b. Photographs of the equipment are included as a separate exhibit. 3. Quantity production is planned. 4. Technical description: a. Emission 180k0F3E b. Frequency range: 656 - 669 MHz. c. Operating power of transmitter is fixed at the factory at 3 mW. d. Maximum power permitted under Part 74.861(e) (1)(ii) of the rules is 250 milliwatts, and the ATW-T76X complied with those power limitations. e. Function of each active semiconductor device: See Appendix 1. f. Complete circuit diagram is included as a separate exhibit. g. A draft instruction book is included as a separate exhibit. h. The transmitter tune-up procedure is included as a separate exhibit. 2 B. GENERAL INFORMATION REQUIRED (Continued) i. A description of circuits for stabilizing frequency is included in Appendix 2. j. A description of circuits and devices employed for suppression of spurious radiation and for limiting modulation is included in Appendix 3. k. Not applicable. 5. Data for 2.985 through 2.997 follow this section. 6. RF_Power_Output (Paragraph 2.987(a) of the Rules) The device has an integral antenna. Effective radiated power (assuming an ideal dipole) was determined, by substitution, as 3 mW. NOTE: All audio measurements were made hard-wired. C. MODULATION CHARACTERISTICS 1. A curve showing frequency response of the transmitter is shown in Figure 1. Reference level was a 1 kHz au- dio signal at 10 kHz deviation. A Boonton 8220 modula- tion meter was used to measure deviation. Audio output was measured from an Audio Precision System One integrated measurement system. 2. Under Section 74.861 no modulation limiting is required. Figure 2 shows deviation as a function of input does not exceed 75 kHz. 3. Occupied_Bandwidth (Paragraphs 2.989, and 74.861(6) of the Rules) Figure 2 is a plot of the sideband envelope of the transmitter taken with a Tektronix 494P spectrum analyzer. Modulation consisted of a 15 kHz tone at an input level necessary to produce 85% of the rated 75 kHz deviation, per 2.989(e)(3). NOTE: Audio bandwidth is 15 kHz, and maximum system deviation is 75 kHz. Using 2D+2F = modulation factor. Where "D" is rated system deviation, and "F" is maximum modulation frequency, an emission designator of 180k0F3E was computed. 3 FIGURE 1 MODULATION FREQUENCY RESPONSE MODULATION FREQUENCY RESPONSE FCC ID: JFZT76X FIGURE 1 4 FIGURE 2 DEVIATION VS INPUT SIGNAL SOLID LINE: 15 kHz LONG DASH: 1 kHz SHORT DASH: 300 Hz DEVIATION VS INPUT SIGNAL FCC ID: JFZT76X FIGURE 2 5 FIGURE 3 OCCUPIED BANDWIDTH OCCUPIED BANDWIDTH FCC ID: JFZT76X FIGURE 3 6 C. MODULATION CHARACTERISTICS (Continued) The plots are within the limits imposed by paragraph 74.861(6). The horizontal scale (frequency is 100 kHz per division) and the vertical scale (amplitude) is a logarithmic presentation equal to 10 dB per division. D. SPURIOUS EMISSIONS AT THE ANTENNA TERMINALS (Paragraph 2.991 of the Rules) NOT APPLICABLE, INTEGRAL ANTENNA. E. DESCRIPTION OF RADIATED SPURIOUS MEASUREMENT FACILITIES A description of the Hyak Laboratories’ radiation test facility is a matter of record with the FCC. The facility meets ANSI 63.4-1992 and was accepted for radiation measurements from 25 to 1000 MHz on October 1, 1976 and is currently listed as an accepted site. F. MEASUREMENTS OF SPURIOUS RADIATION Measurements of radiated spurious emissions from the ATW- T76X were made by substitution with a Tektronix 494P spectrum analyzer using Singer DM-105A calibrated dipole antennas below 1 GHz, and Polarad CA-L, and CA-S or EMCO 3115 from 1-8.0 GHz. The transmitter was located in an open field 3 meters from the test antenna. Supply was a fresh battery. The transmitter and test antennas were arranged to maximize pickup. Both vertical and horizontal test antennae polarization were employed. Reference level for the spurious radiation was taken as the carrier level. 7 TABLE 1 TRANSMITTER RADIATED SPURIOUS 663.000 MHz, 9 Vdc, 3 mW Spurious dB Below Frequency Carrier ___MHz__ Reference 1 663.005 0 1326.012 37V 5967.046 35H Required: 43+10Log(P) 18 1 Worst-case polarization, H-Horizontal, V-Vertical. All other spurious to 7 GHz were 20 dB or more below FCC limit. 8 G. FREQUENCY STABILITY (Paragraph 2.995(2) and 74.861 of the Rules) Measurement of frequency stability versus temperature was made at temperatures from -30 o C to +50 o C. At each temperature, the unit was exposed to test chamber ambient a minimum of 60 minutes after indicated chamber temperature ambient had stabi- lized to within ±2° of the desired test temperature. Following the 1 hour soak at each temperatu…

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