MMA710150ALicensed Non-Broadcast Station Transmitter

Front View Top View Bottom View Left Side View Right Side View Rear View

Description 71-0150 © Midland Radio Corporation 12 CIRCUIT DESCRIPTION RECEIVER PART 1) RF section: An incoming signal is fed to pre-selector (BPF-101), and amplified by Q101, then fed to post-selector (BPF-102). The balanced mixer, consisting of T101, T102, D107 and D108, produces 21.6MHz by injection from the 1 st local signal provided by Rx. 2) Noise Blanking Section: The noise blanking circuit consists of Q102 (1 st noise amplifier), Q121 (buffer amplifier), Q122 (2 nd noise amplifier), Q123 (3 rd noise amplifier), Q125 (1 st pulse amplifier), Q104 (2 nd pulse amplifier), and a blanker switch formed by D103 through D106. An incoming signal is divided by the 1 st RF amplifier (Q101) to feed the 2 nd BPF and to feed the 1 st noise amplifier. A noise is amplified by Q102, Q121, Q122, Q123, Q125 and Q104. Then the amplified pulse triggers the blanker switch to eliminate the noise within the RF signal. 3) IF section: The output signal from the balanced mixer is fed to the crystal filters (XF101), then amplified by Q103. Again, this signal is fed to the 4-pole crystal filters and amplified by Q113. After being amplified by Q113, the signal is fed to 2 nd IF processor IC (IC106). The 2 nd local crystal oscillator signal is fed to IC106 to produce the 2 nd local signal (455KHz). IC106 amplifies the 2 nd local signal, which becomes an audio signal after the detector circuit included in IC106. Then, the audio signal is fed to the low-pass filter included in IC107, and fed to audio processor IC (IC3). 4) VCO section: The oscillator circuit formed by L303, D303, D305 and Q301 produces the 1 st local signal (Rx frequency plus 21.6MHz). The 1 st local signal is amplified by buffer amplifier Q302, and again amplified by pre- amplifier IC301 and post amplifier Q303. The amplified signal is fed to the balanced mixer. 5) PLL section: PLL IC with pre-scaler IC101 compares the phase between the VCO frequency and reference oscillator frequency (12.00MHz) by method of dividing the frequency, and produces VCO control signal. Then, this control signal is fed to the charge pump, consisting of Q108, Q109 and Q110, and fed to the LPF. The supply voltage of charge pump is multiplied by IC102 (approx. 15V) to achieve greater C/N ratio. TRANSMITTER PART 1) VCO section: The oscillator circuit formed by L303, D305 and D306 generates transmitter frequencies. Then this signal is fed to the 3-stage of amplifiers, buffer amplifier Q302, pre-amplifier IC301 and post amplifier Q303 and then to the final amplifier. 2) PLL section: Basically, the circuit description is the same as Rx. PLL IC with pre-scaler IC205 compares the phase between the VCO signal and reference oscillator frequency (12.00MHz) by method of dividing the frequency, and produces VCO control signal. Then this VCO control signal is fed to the charge pump, Description 71-0150 © Midland Radio Corporation 13 consisting of Q206, Q207 and Q208, and fed to the LPF. The supply voltage of charge pump is amplified by IC206 (approx. 15V) to achieve greater C/N ratio. 3) Modulator section: The modulation signal is fed to both VCO and the reference oscillator (TCXO); this permits very flat modulation characteristics against low frequency (DC). 4) TX Pre-amp section: The VCO signal is amplified by Q215 and Q216 to achieve 250mW. 5) PA section: The signal from pre-amp stage is fed to Q501 (semi-driver), Q506 (driver) and Q508 (final amplifier) to achieve 50W output power. Then, signal is fed to the LPF to eliminate the harmonics spurious frequencies. An APC circuit formed by IC502, IC503, Q504 and Q505 stabilizes the output power at the set level. An IC501 protects PM501 and Q501 from the reverse power caused by the un-matched aerials. LOGIC PART 1) Microcomputer (CPU) section: A CPU, IC-1, uPD78F005 is the 8-bit processor with 60K flash memory and 2K RAM inside. This CPU controls all functions of the radio. A flash memory permits ON-BOARD-UP-GRADE when the new software is released. 2) EEPROM section: An IC7 is the 64kbit EEPROM. This IC contains all channel parameters 3) Audio processor section: IC2 is for TX and IC3 is for Rx audio processing. These IC’s control all audio processing and encode/decode CTCSS tones as commanded by the CPU. These IC’s also have a 2400bps MODEM to enable to form MPT1327 trunking protocols by using external MPT control software. FRONT CONTROL PANEL PART 1) LCD display section: LCD display is constructed by 128 x 32 dot matrix. This allows indication not only of characters but also graphics and symbols as designed. 2) LED display section: The 4 LED’s indicate modes of operation. 3) Audio amplifier section: IC404 has 2W audio power to drive the 8-ohm speaker mounted on the panel 4) Microphone pre-amplifier section: IC401 is the voice pre-amplifier having –34dBm output to feed the TX modulator. Description 71-0150 © Midland Radio Corporation 14 REMOTE CONTROL 25 pin D-sub connector for remote control is provided on the rear panel. The functions of each pin are as follows: Pin No. Name Description I/O Levels Comments 1 CH0 LSB external binary channel selection I 0-+5VDC 000000 is channel 1 2 CH1 External binary channel selection I 0-+5VDC 3 CH2 External binary channel selection I 0-+5VDC 4 CH3 External binary channel selection I 0-+5VDC 5 CH4 External binary channel selection I 0-+5VDC 6 CH5 MSB external binary channel selection I 0-+5VDC 7 GND 8 RSSI Receive signal strength indicator O 0-+2VDC analog 9 DISC OUT Discriminator audio out O ≈330mVrms 1KHz @ ±3KHz 10 SQ CONT Squelch control I 11 BUSY Channel busy indication O 0-+5VDC 5V=busy 12 MUTE External audio mute I 0-+5VDC 0V=muted 13 MOD1 External audio modulation input I ≈50mVrms 1Khz for ±3KHz 14 GND 15 PTT Push to talk I 0-+5VDC 0V=transmit 16 MOD2 External modulation input I ≈400mVrms 1KHz for ±3KHz After limiter and filtering 17 SIMP Simplex mode selected O 0-+5VDC 0V=simplex 18 ERR Alarm indication O 0-+5VDC 5V=alarm 19 DECODE Decode valid indication O 0-+5VDC 5V=valid signaling 20 RX…

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Preparation 71-0150 © Midland Radio Corporation 4 ALIGNMENT PROCEDURES RECEIVER PART 1) BPF-101 and BPF-102 alignment Connect the signal generator to the Rx antenna connector of the unit. Align the BPF-101 and BPF-102 to obtain the maximum sensitivity. For better alignment, if you have spectrum analyzer and tracking generator, connect the tracking generator to the Rx antenna connector and pick up the output signal from J101 to connect spectrum analyzer. Align the BPF-101 and BPF-102 to cover the desired bandwidth of receiving frequencies. 2) FVR101 alignment This is to adjust the tight squelch level. 3) VCO alignment The VCO has been aligned at the factory to cover full bandwidth. However, if you need to re-adjust the VCO when you repair, set the VCO voltage at 10.5V by L303 at the highest band frequency. TRANSMITTER PART 1) FVR201 alignment This potentiometer determines the modulation level. Carefully align FVR201 to obtain flat deviation from the lowest to the highest frequency installed in the transmitter. 2) FVR202 alignment This potentiometer determines the low frequency (below 300Hz) deviation. When CTCSS or DCS are used, it is necessary to align FVR202 to have enough deviation at low frequency. FVR204 FVR203FVR202FVR201 3) FVR203 alignment FVR203 sets the maximum deviation, normally set at 5KHz. Also 2KHz or 2.5KHz deviation, for narrow spacing, can be selected with the programming software. 4) FVR204 alignment FVR204 adjusts the output power supplied to the transmitter. 5) VCO alignment The VCO has already been aligned at the factory, however if you need to re-adjust, set the VCO voltage to 10.5V at the highest band frequency. Preparation 71-0150 © Midland Radio Corporation 5 POWER AMPLIFIER PART 1) FVR505 Adjust FVR505 to gain the maximum efficiency as well as the maximum power output at the final transistor of the power amplifier. 2) FVR501 Adjust FVR501 for minimum reverse power when the antenna is terminated with 50 ohms load. 3) FVR502 FVR502 sets the point where reverse power is detected. 4) FVR503 FVR503 sets the point where a low-power-alarm is triggered. 5) FVR504 FVR504 sets the maximum power from the power module, however, do not exceed 55 watts. LOGIC PART FVR1 FVR2FVC1 FVR3 1) FVR1 alignment Set FVR1 to obtain 0dBm output into 600 ohms. 2) FVR2 alignment Adjust FVR2 for flat deviation level when used for a repeater. 3) FVR3 alignment FVR3 adjusts the power level indicator on the LCD. 6) FVC1 alignment Use FVC1 to shift the CPU clock frequency when necessary. A beat interference sometimes happens at certain frequency. In such case, shifting the CPU clock frequency may eliminate the interference. Preparation 71-0150 © Midland Radio Corporation 6 FRONT CONTROL PANEL PART FVR401 Hi FVR402 Lo VR401 VR402 FVR403 1) VR401 alignment This is a volume controller. 2) VR402 alignment This is a squelch level controller. 3) FVR401 alignment Use FVR401 to set the HI-POWER-LEVEL of the Tx output power. 4) FVR402 alignment Use FVR402 to set the LO-POWER-LEVEL of the Tx output power. 5) FVR403 alignment This is to set the contrast of the LCD back light.

75P A C R285※ 10μC223 10KR217 SIMP REF VCO CK DATA TX2 TX1 +12V GND C241 2.2n C245 82P R221 100K FLC202 47K R254 15P C252 C2260.1μ R23647K R286 ※ R21910K C2281.5μGRM42 2.7KR234 D206:A DA204U D206:B 10μ C224 100Ω R222 47ΩR230 15n C218 R22947Ω 10μ C221 D205 1SS355 1μ C209 GRM42 2SK3018Q206 18K R228 R2251KC255 10n C219 2.2μ/16V C229 ※ 10KR215 10KR216 220PC215 D2021SS355 0.22μC208 BLM21BL203 PW.CONT 100KFVR203 C207 47P 100KR210GRM421μC205 R20710K BL205BLM21 ERR TCXO TX.OUT R211180K 4.7KR206 C210 1n C212 10μ R26410Ω LE +12V R242※ R20468K 150PC240 R2371.5K R20210K Q202 FMG9A 10KR203 1 2 IC202 TA78M05F C242 ※ R20110K BL202HM501 BL201HM501 10Ω 1/8W R271 C243 2.2n L201:B 10KR261 R240470Ω 1/8W 10KR243 C257 1μ C23933μ R2720Ω 1/8W 82PC245 R27710K 1n C238 5KFVR204 C250 ※ D2101SS355 R255 47K R2608.2K C249 5P R249 47K 10n C235 65 4 7 NJM2904IC209:B 100KR256 100KR253 R2801.8K C254 2.2n R2511.5K C233 2.2n 470ΩR252 100mW 470ΩR233 47n C227 10μ C225 39K R231 R227 27K C256 22n R21312K R22410K C236470P R22610K V C O BLM21BL204 100KR209 C204 100P 4 23 1 TS272CD IC203:A 200KFVR202 4.7μ C202 R265270Ω 1SS356 D212 R235※ D201 UDZ2.4B R2674.7Ω 2SC2954 Q215 Q2012SK2731 L201:A#1092 0.15μC230 C231 1n R24615K Q214 IMX1 1n C248 R25747K D211RB501V C232 10n R2781.8K Q2172SK880※ C237 2.2n C251 5P 2SK3018 Q208 2SJ166 Q207 1KR232 C222 10μ 4.7KR223 2 5 3 1 4 UMC2NQ203 R21215K 15nC220 MB1511 IC205 2SK3018Q204 10μ C213 47n C214 10P C217 BL207BLM21 FVR201 10K 270ΩR239 R244 47K 4.7KR268 R270 470Ω 150ΩR266 C244 1n R26210K R250180K R247100K ※R258 R2480Ω R259150K 47nC234 39KR263 470Ω 1/8W R279 51TX321 KG510-03B BU4S66 IC207 4 352 1 UMC2NQ209 D207:A DA204U D207:B IC206 NJU7662M 2SD2351Q205 ※R284 TA75S01F IC204 8.2K R214 ※C206 C211 47n DC OUT GND V.C. 12.00MHzOSC201 12 CS202 BL206HM501 R238※ 1 3 IC201 AN78L05M 560KR205 2SB1184Q212 C203 1μ 10μ C201 R2694.7Ω Q211FMG2A 10KR241 32 1 8 NJM2904 IC209:A FMG2AQ210 2.2ΩR274 CN201 2.2nC253 L2030.1μH 2A-SA0033-2 D214 SML210-VT TX UNIT CIRCUIT DIAGRAM 16 15 14 13 12 11 10 4 5 6 7 8 9 3 2 1 CN202 56 7 8 TS272CD IC203:B 1 6 CS201 3 12 IC208M5237ML A ※4P PWIN ERR ※※ C511UC551n POW R546 ※ R547 5.6KR550R545 2.2Ω68Ω R505 33ΩC559 150PC538 ※C536 5PC534 150PC532 150PC521 150PC514 330PC511C513 1n390P C508C510 200P1n C C529 4.7n C530 4.7n C537C558C560 ※※150P C535C520C522C533 150P150P150P120P R502150Ω 33Ω R503 2.2nC501 100KR533 TH50168Ω ※ C504 100ΩR506 2SC2412KQ504 ※R527 1KR528 R530100K 270ΩR531 10Ω1/2WR509L503HM501 R5082.2K KQ1008 L502 4.7μ R52947K 3 1 4 2 5 TA75S01F IC502 33μ/25V C552 C508 180P 2KFVR503 D5071SS355 3.9KR523 5.6KR524 5.6KR522 HM501BL501 R555 0Ω1/8W R551 47Ω 1/8W R515 47K 6.8K R518 2KFVR502 C5494.7n C517 2.2n 4A-S629 L504 56 7 8 BAM4558F IC501:B 1K R521 FL06BT04 L505 R556 1Ω1/2W 270ΩR539 2SK2731Q507 GRM40 C543470P L506 TP501RCT C5414.7μ C5162nUC55 UC34120PC521 L507 RB521SD503 4.7KR547 ※ C523 C5245P FVR501200Ω UC23100PC522 R5402.7K C5454.7n HM501BL507 C5284.7n 33ΩR545 D505 RB501V 2.7K R543 R542 4.7K C5404.7n C531 2n UC34 4P C536UP050 321 CN503 ※ C537UP050 L510 TO CP501 C538UC23※ CN501 C5024.7n1KR537 2.2KR538 0.1μC553 1SS355 D501 R505 33Ω 0ΩL501 4.7nC505 470Ω1/8W R507 2n UC55C509 1.2KR520 R550 4.7Ω1/8W BL512FBA04.900 R517100K C5460.22μ C547 4.7n C548 4.7n 470ΩR513 UC34220PC512 UC34330PC513C515470PUC34 FC501IHB340 C514220PUC34 UC34120PC520 ※UC34C519 100P FVC505 10K R548 R51010K 4.7nC527 R541 4.7K UC23C558※ C532 UC23 100P FC502IHB340 C559100PUC23 C534UC23100P C535UC23 100P 470KR516 1.5K3.3Ω27Ω22Ω82P75P75P100P180P820P270P150P820P DC IN ←→ DC510 82P75P75P75P75P 1 2 3 M5237ML IC503 4.7KR535 2SB1018AQ505 D5021SS355 1.8KR501 150ΩR504 C5032.2n FVR504 100K C551 ※ 4 1 23 BAM4558F IC501:A R526100K 100KR525 10K R519 C5552.2μ/16V FC503IHB340 C5180.1μLead 47ΩR552 C561※UC34 C510820PUC55 R5145.6K D506UDZ2.4B HM501BL510 DTB143EKQ503 D509 1SS355 10KR512 UC34 C544470P FBA04.900 BL505 FBA04.900BL506 C542 GRM40 0.01μ C5264.7n R553Lead 33Ω R554 Lead 100Ω D504 RB501V L508 BL509FBA04.900 PW CONT FBA04.900BL517 TP502RCT HM501 BL508 L509 CN502 L511 2A-SA0028-2 270Ω 1WR532 12KR534 33μ/25V C554 2SC1947 Q501 1SS355 D508 C5500.1μ C5560.1μ C506 4.7n Q5062SC1729 2.2n C507 1 3 IC504 AN78L05M Q502DTC124EKA R51110K SML-210VT D510 Q508MRF454 BL514FBA04.900 4.7nC525 ※ C539UC34 35MHz---45MHz C533UC23100P C560UC23100P BL516FBA04.900 KG510-03B 51PA321 180KR536 PA UNIT CIRCUIT DIAGRAM GNDCKERRNC A C 1nC104 4.7KR103 D113:B 10KR139 L1163.3μ N/WLENC 10KR101 C115 4.7n C1271μ 1.1KR166 47n C180 R106 47Ω D102 HVU131 D112:B 1-LOCOL C121 4P 51RX321 ＋12VDSC.OUTBUSYRSSIDATA No R107 4.7K 10μ L105 4.7KR015 C195220P L1010.1μH HVU131 D101 C192220P 100KR009R0101.5K 2.2KR006R005150K C108 2.2n C107 4.7n C1530.1μ R1552.7K C154 ※ 100KR0010ΩR000 4.7μL103 KQ1008 R107 2.7K 15n C150 1K R153 DA204UD112:A R154 470Ω C14910μ BL103BLM21 C148 10μ L106 10μ C1174.7n 39K R152 2SJ166Q108 47Ω R150 100KR149 BL104HM501 C10510n R11410K R102 18K 56ΩR121 R1100Ω C10622P 4.7KR141 C146 10μ 10μC145 L1130Ω 10μL111 1.5μL110KQ1008 D107:A1SS271 R136 6.8K R137 10K 10KR138 C1437P 47KR129 C1311μ 1P C114 R120※C124 5P BLM21BL102 R1221.5K 75PC118 4PC119 0.22μC141 D119SML210-VT 1.5KR124 D106HVU131 0.5PC158 R13310KR13210K D120 UDZ3.6B 1.5μL114 C1354.7n 4.7KR186 4.7nC164 R165 330Ω 470ΩR164 100KR188 2SK3018Q120 1nC168 3.3KR189 C1892.2n CF101 455G 455E CF102 R18410K 15n C187 C184 GRM42 1μ C183100P 470KR168 470P C172 BL101HM501 15n C186 C175 2.2n 22n C174 SQ CONT＋12VRX/SWSIMP D123RB501V R174 22K C178 1μ GRM42 10KR1721SS355 D117 R18275K FLC102 CN101 R013560K 2SA1434 Q124 R012180K C19415P R014 820K ※C101 C103 ※ C191 2.2n Q1232SC4250 100ΩR011 R00847Ω R00447Ω Q1222SC4250 100ΩR007 C162 2.2n Q101 3SK177 R10410K 4 1 352 UMC2NQ111 C16047P R108 47Ω 470PC110 C109 2.2n R148 100Ω 100ΩR118 R11668Ω R19122K 2SK3018Q109 J101 R11510K L1090.27μ 2SK3018Q110 Q107 2SD2351 R126 39K C132 5P D108:A1SS271 C125180P 150Ω R119 4.7nC128 C142150P 6.8KR128 100KR127100KR125 4.7nC129 R123100Ω C166 15n 1SS355 D110 47n C137 TA75S01F IC105 4.7KR109 R112100K 75PC120 D104 HVU131 HVU131 D103 Q104 2SK3018 4.7nC126 C12268P CP103 21.6M…

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APPLICANT: MIDLAND RADIO CORPORATION FCC ID: MMA710150A REPORT #: T:\M\MidlandRadio_MMA\737UT2\737UT2TestReport.doc TABLE OF CONTENTS LIST TABLE OF CONTENTS LIST APPLICANT: MIDLAND RADIO CORPORATION FCC ID: MMA710150A TEST REPORT: PAGE 1-2....COVER SHEET - GENERAL INFORMATION & TECHNICAL DESCR. PAGE 3......RF POWER OUTPUT PAGE 4......MODULATION CHARACTERISTICS PAGE 5......AUDIO FREQUENCY RESPONSE PLOT PAGE 6......MODULATION LIMITING PLOT – 300 Hz PAGE 7......MODULATION LIMITING PLOT – 1000 Hz PAGE 8......MODULATION LIMITING PLOT – 3000 Hz PAGE 9......AUDIO LOW PASS FILTER PLOT PAGE 10.....OCCUPIED BANDWIDTH PAGE 11.....OCCUPIED BANDWIDTH PLOT PAGE 12.....OCCUPIED BANDWIDTH PLOT – CW PAGE 13.....SPURIOUS EMISSIONS AT ANTENNA TERMINALS PAGE 14.....METHOD OF MEASURING SPURIOUS EMISSIONS AT ANTENNA TERM. PAGE 15.....FIELD STRENGTH OF SPURIOUS EMISSIONS PAGE 16.....METHOD OF MEASURING RADIATED SPURIOUS EMISSIONS PAGE 17.....FREQUENCY STABILITY PAGE 18-21..LIST OF TEST EQUIPMENT EXHIBITS CONTAINING: EXHIBIT 1.........FCC ID LABEL SAMPLE EXHIBIT 2.........SKETCH OF LOCATION EXHIBIT 3.........BLOCK DIAGRAM EXHIBIT 4.........SCHEMATICS EXHIBIT 5.........USER'S MANUAL EXHIBIT 6.........EXTERNAL PHOTOS EXHIBIT 7.........INTERNAL PHOTOS EXHIBIT 8.........TUNING PROCEDURE EXHIBIT 9.........CIRCUIT DESCRIPTION EXHIBIT 10........TEST SETUP PHOTOGRAPHS APPLICANT: MIDLAND RADIO CORPORATION FCC ID: MMA710150A REPORT #: T:\M\MidlandRadio_MMA\737UT2\737UT2TestReport.doc Page 1 of 21 GENERAL_INFORMATION_REQUIRED FOR_TYPE_ACCEPTANCE 2.1033(c)(1)(2)MIDLAND RADIO CORPORATION will manufacture the FCCID: MMA710150A VHF TRANSCEIVER in quantity, for use under FCC RULES PART 90. MIDLAND RADIO CORPORATION 1120 CLAY STREET NORTH KANSAS CITY, MO 64116 2.1033 (c) TECHNICAL_DESCRIPTION 2.1033(c)(3) Instruction book. A draft copy of the instruction manual is included as EXHIBIT 5. 2.1033(c) (4) Type of Emission: 10K6F3E 90.209 Bn = 2M + 2DK M = 3000 D = 1900 Bn = 2(3000)+2(2300) = 10.6k 90.217(b) Authorized Bandwidth 12.5 kHz 2.1033(c)(5) Frequency Range: 30-50 MHz 90.209 2.1033(c)(6)(7) Power Output shall not exceed 59 Watts into a 50 ohm 90.205 resistive load. There are no user power controls. 2.1033(c)(8) DC Voltages and Current into Final Amplifier: POWER INPUT: FINAL AMPLIFIER ONLY Vce = 13.6 Volts IC LOW = 7.9 A IC HIGH = 10.8 A 2.1033(c)(9) Tune-up procedure. The tune-up procedure is included in Exhibit 8. 2.1033(c)(10) Complete Circuit Diagrams: The circuit diagram is included as EXHIBIT 4. The block diagram is included as EXHIBIT 3. APPLICANT: MIDLAND RADIO CORPORATION FCC ID: MMA710150A REPORT #: T:\M\MidlandRadio_MMA\737UT2\737UT2TestReport.doc Page 2 of 21 2.1033(c)(11) A photograph or a drawing of the equipment identifica tion label is included as Exhibit #1. 2.1033(c)(12) Photographs(8"X10") of the equipment of sufficient clarity to reveal equipment construction and layout, including meters, labels for controls, including any view under shields - See EXHIBIT 6-7. 2.1033(c)(13) Digital modulation is not allowed. 2.1033(c)(14) The data required by 2.1046 through 2.1057 is submitted below. APPLICANT: MIDLAND RADIO CORPORATION FCC ID: MMA710150A REPORT #: T:\M\MidlandRadio_MMA\737UT2\737UT2TestReport.doc Page 3 of 21 2.1046(a) RF power output. 90.205 RF power is measured by connecting a 50 ohm, Resistive wattmeter to the RF output connector. With a nominal battery voltage of 13.6 VDC, and the Transmitter properly adjusted, the RF output measures: INPUT POWER: HIGH: (13.6V)(7.9A) = 107.44 Watts INPUT POWER: LOW: (13.6V)(10.8A) = 146.88 Watts OUTPUT POWER: HIGH: 59 Watts LOW: 33 Watts METHOD OF MEASURING RF POWER OUTPUT APPLICANT: MIDLAND RADIO CORPORATION FCC ID: MMA710150A REPORT #: T:\M\MidlandRadio_MMA\737UT2\737UT2TestReport.doc Page 4 of 21 2.1047(a)(b) Modulation characteristics: AUDIO FREQUENCY RESPONSE The audio frequency response was measured in ac- cordance with TIA/EIA Specification 603. The audio frequency response curve is shown on page 5. The audio signal was fed into a dummy microphone circuit and into the microphone connector. The input required to produce 30 percent modulation level was measured. 2.1047(b) Audio input versus modulation The audio input level needed for a particular per- percentage of modulation was measured in accor- dance with TIA/EIA Specification 603. The audio input curves versus modulation are shown in pages 6-8. Curves are provided for audio input frequen cies of 300, 1000, and 3000 Hz. Post Limiter Filter The filter must be between the modulation limiter and the modulated stage. At any frequency between 3 & 20 kHz the filter must have an attenuation of 60log (f/3) greater that the attenuation at 1KHz. See the plot; page 9. APPLICANT: MIDLAND RADIO CORPORATION FCC ID: MMA710150A REPORT #: T:\M\MidlandRadio_MMA\737UT2\737UT2TestReport.doc Page 5 of 21 AUDIO RESPONSE GRAPH Midland Radio Corp. 71-0150A -70 -65 -60 -55 -50 -45 -40 -35 100100010000 Frequency dBmV audio response APPLICANT: MIDLAND RADIO CORPORATION FCC ID: MMA710150A REPORT #: T:\M\MidlandRadio_MMA\737UT2\737UT2TestReport.doc Page 6 of 21 MODULATION LIMITING GRAPH – 300 Hz Modulation Limiting Midland Radio Corp. 71-0150A 0 500 1000 1500 2000 2500 -56-46-36-26 dBmV Deviation 300 Hz APPLICANT: MIDLAND RADIO CORPORATION FCC ID: MMA710150A REPORT #: T:\M\MidlandRadio_MMA\737UT2\737UT2TestReport.doc Page 7 of 21 MODULATION LIMITING – 1000 Hz Modulation Limiting Midland Radio Corp. 71-0150A 0 500 1000 1500 2000 2500 -68-58-48 dBmV Deviation 1000 Hz APPLICANT: MIDLAND RADIO CORPORATION FCC ID: MMA710150A REPORT #: T:\M\MidlandRadio_MMA\737UT2\737UT2TestReport.doc Page 8 of 21 MODULATION LIMITING – 3000 Hz Modulation Limiting Midland Radio Corp. 71-0150A 0 500 1000 1500 2000 -72-62-52-42-32 dBmV Deviation 3000 Hz APPLICANT: MIDLAND RADIO CORPORATION FCC ID: MMA710150A REPORT #: T:\M\MidlandRadio_MMA\737UT2\737UT2TestReport.doc Page 9 of 21 APPLICANT: MIDLAND RADIO CORPORATION FCC ID: MMA710150A REPORT #: T:\M\MidlandRadio…

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