AAO2101679CB Transceiver

Front View Back View Top View Side View – Jack Side View - PTT

PCB – Bottom PCB - Top

ENGINEERING STATEMENT For Type Certification of Radio Shack, a Div. of Tandy Corporation Model No: TRC-241 FCC ID: AAO2101679 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 authorized by Radio Shack, a Division of Tandy Corporation, to make type certification measurements on the TRC-241 transceiver. These tests were made by me or under my supervision in our Springfield laboratory. Test data and documentation required by the FCC for type certification are included in this report. It is submitted that the above-mentioned transceiver meets all applicable FCC require- ments. ______________________________ Rowland S. Johnson Dated: September 25, 2000 A. INTRODUCTION The following data are submitted in connection with this request for type certification of the TRC-241 transceiver in accordance with Part 2, Subpart J of the FCC Rules. The TRC-241 is a double sideband amplitude modulated trans- mitter/receiver combination intended for portable operation in the citizens radio service. The transmitter has 40-channel capability in the 26.965 - 27.405 MHz band utilizing phase locked loop (PLL) technology. ERP (d) at 27 MHz is 6 mW. B. GENERAL INFORMATION REQUIRED FOR TYPE CERTIFICATION (Paragraph 2.983 of the Rules) 1. Name of applicant: Radio Shack, a Div. of Tandy Corp. 2. Identification of equipment: FCC ID: AAO2101679 a. The equipment identification label is submitted as a separate exhibit. b. Photographs of the equipment are submitted as a separate exhibit. 3. Quantity production is planned. 4. Technical description: a. 6k00A3E emission b. Frequency range: 26.965 - 27.405 MHz c. Operating power of transmitter is fixed at the factory at less than 4 watts and can be reduced 6 dB. d. Maximum power rating under 95.635(c) of the Rules is 4 watts. e. The dc voltage and dc currents at final amplifier: Collector voltage: 11.9 V Collector current: 0.56 mA @ 12.0 Vdc input. f. Function of each active semiconductor device: Submitted as a separate exhibit. g. Complete ciruit diagram is submitted as a separate exhibit. h. A draft instruction book is submitted as a separate exhibit. i. The transmitter tune-up procedure is submitted as a separate exhibit. 2 B. GENERAL INFORMATION...(Continued) j. A description of circuits for stabilizing frequency is included in Appendix 1. k. A description of circuits and devices employed for suppression of spurious radiation and for limiting modulation is included in Appendix 2. l. Not applicable. 5. Data for 2.985 through 2.997 follow this section. 6. RF_Power_Output (Paragraph 2.985(a),(b)(1) of the Rules) RF power output in the AM mode was measured with a Bird 4421 RF power meter and a Narda 765-20 50 ohm dummy load. (The transmitter was tuned by the factory.) Power was measured with a supply voltage of 12.0 volts, and indicated: Channel Power, W High Low 1 3.8 0.96 21 3.6 0.95 40 3.5 0.95 C. MODULATION CHARACTERISTICS 1. AF_Frequency_Response A curve showing frequency response of the transmitter is shown in Figure 1. Reference level was taken as a 1 kHz tone with 50% modulation, as measured on a Data Tech 209 modulation meter, using Audio Precision System One digital voltmeter and tracking generator. 2. Modulation_Limiting Curves of AM modulation limiting for both positive and negative peaks are shown in Figures 2a and 2b, respec- tively. Characteristics at 300, 1320, and 2500 Hz are shown using a Data Tech 209 modulation meter. Signal level was established with a Audio Precision System One digital voltmeter. The curves show compliance with Paragraph 95.633(d) of the Rules. 3 C. MODULATION REQUIREMENTS...(Continued) 3. Modulation_Limiter_Attack_Time Modulation limiter attack time was measured by applying to the microphone input terminals a pulsed tone at 2500 Hz, 16 dB above the level required for 50% modulation at the frequency of maximum response, 1320 Hz. The spectrum analyzer was tuned to upper and lower fourth- order sidebands in the time domain. Horizontal sweep of the analyzer was triggered in synchronism with the tone turn-on. Sweep speed was 100 milliseconds per division. Plots are included as Figures 3a and 3b. Any transients observed in excess of 33 dB attenuation as referenced to the carrier were less than 20 ms in duration. 4 FIGURE 1 TRANSMITTER FREQUENCY RESPONSE TRANSMITTER FREQUENCY RESPONSE FCC ID: AAO2101679 FIGURE 1 5 FIGURE 2a AM MODULATION LIMITING - POSITIVE PEAKS MODULATION LIMITING CHARACTERISTICS Percent modulation as a function of input level at microphone jack in dBm for 300 Hz, 1320 Hz, and 2500 Hz tones. MODULATION LIMITING POSITIVE PEAKS FCC ID: AAO2101679 FIGURE 2a 6 FIGURE 2b AM MODULATION LIMITING - NEGATIVE PEAKS MODULATION LIMITING CHARACTERISTICS Percent modulation as a function of input level at microphone jack in dBm for 300 Hz, 1320 Hz, and 2500 Hz tones. MODULATION LIMITING NEGATIVE PEAKS FCC ID: AAO2101679 FIGURE 2b 7 FIGURE 3a MODULATION LIMITER ATTACK TIME Measurement_Conditions: 16 dB over 50% modulation level at 1320 Hz with 2500 Hz tone, upper fourth order sideband; horizontal scale 100 ms/div. UPPER FOURTH-ORDER SIDEBAND LIMITER ATTACK TIME FCC ID: AAO2101679 FIGURE 3a 8 FIGURE 3b MODULATION LIMITER ATTACK TIME Measurement_Conditions: 16 dB over 50% modulation level at 1320 Hz with 2500 Hz tone, lower fourth order sideband; horizontal scale 100 ms/div. LOWER FOURTH-ORDER SIDEBAND LIMITER ATTACK TIME FCC ID: AAO2101679 FIGURE 3b 9 C. MODULATION CHARACTERISTICS (Continued) 4. Occupied_Bandwidth_-_AM (Paragraph 2.989(c) of the Rules) Figures 4a and 4b are plots of the sideband envelope of the transmitter taken from a Tektronix 494P spectrum analyzer for both nominal 4 watt and 1 W power. Modula- tion corresponded to conditions of 2.989(a) and con- sisted of 2500 Hz tone at an input level 16 dB greater than that necessary to produce 50% modulat…

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