TABLE OF CONTENTS CHAPTER 1 Transmitter General Description And Installation Procedures Page 2 Remote Control Feature Page 5 Analog telemetry Option Page 7 Programming the NT 350 Page 8 CHAPTER 2 Electrical Specifications Page 13 Mechanical Specifications Page 15 CHAPTER 3 350 W schematics and components list Page 16 1
CHAPTER 1 GENERAL DESCRIPTION NT 350 Transmitter - Exciter INTRODUCTION The NT-350-LCD is a highly integrated broadband solid-state Mos-Fet FM transmitter of 350W rated power, fitted in a 3 unit rack, which do not require any specific calibration to operate in the 87.5 ÷ 108 MHz frequency range. The unit is microprocessor controlled with an optional PC interface.
INSTALLATION After unpacking the unit, check for any mechanical damage or loose parts inside. If there is any transportation damage, inform the supplier immediately and do not put the module into operation. The applicable voltage is 110 or 220v depending on how the unit was ordered. Please check the back of the unit for the voltage that the unit was set to, and if it is the wrong one, please call Nicom for instruction on how to set the voltage.
Now you can input modulation. For MONO operation connect your signal to the XLR connector or BNC, Depending on the model. Following the connecting instructions printed on the back of the transmitter and then regulate the input level with the apposite trimmer. For stereo input, use the BNC connector labeled “MPX”. Regulate the audio with the apposite trimmer. Note:Be sure that the modulation level is close to but not more than 75KHz. 75KHz is 100% modulation.
REMOTE CONTROL FEATURE The NT 350 is equipped with a 9 pin RS 232 connector that allows all the mains telemetry functions. The software is supplied with the unit and with this CD rom it's possible to monitor and to change the main parameters ot the NT 350 on the computer's screen. The NT 350 is also supplied with the interlock connector that allows to switch the power on and off simply by grounding the inner conductor of the BNC. NOTE: The CD (optional) contains the remote control software of the NT 350.
REMEMBER TO CLOSE THE PROGRAM BEFORE REMOVING THE CONNECTING CABLE RUNNING THE PROGRAM Once the program is running, from the main screen it is necessary to click the POWER ON button; the screen will light up and a message" COMMUNICATION IN PROGRESS" will appear. After few seconds, on the left side of the screen, the operating frequency will appear together with all the other parameters. If not, check the Communication port setting (COM1-COM 2). To change it, click the File menu and then select "set Port".
An Analog telemetry option is available for installation as an option, to be specified at time of purchase. Below is a diagram of the connections on the RS232 port. NOTE: IF THE ANALOG TELEMETRY OPTION IS SELECTED AT TIME OF PURCHASE, THE REMOTE CONTROL SOFTWARE DESCRIBED BELOW WILL NOT WORK.
NT 350 PROGRAMMING Connect a 50 ohm load or 50 ohm antenna to the RF output, connect the equipment into a mains supply (120 or 240 VAC). The equipment is factory pre-set to 50 W. Switch ON the power and the yellow V POWER LED will light. The Display will show: WAIT PROGRAM SETTING After 3 seconds the green PLL LOCK led will light and the Display will show an increasing bar. After a further 5 seconds the green ENABLE will light and there will be output power.
Display Password The Password mode is factory set to enable, and is not possible change this setting. The default password is 1 2 3. The way for changing the password is the following: • Press the PROGRAM key for 3 seconds; PROGRAM PASSWORD 0123456789 • SETTING Press the PROGRAM key to move the underscore character position at the required digit, and press the SETTING key to confirm the digit. PASSWORD * 0123456789 PROGRAM SETTING Repeat the same for the two remaining digits.
If the password is not correct an error is displayed: ERROR PASSWORD PROGRAM SETTING After a few seconds the display will show the parameters again. When the password is correct, the display will show: NEW PASS . = SET. NEW FREQ . = PRG . PROGRAM SETTING To change the password press the SETTING key. To change the frequency press the PROGRAM key.
If the confirmation password is wrong the display will show: PROGRAM ERROR CONFIRMATION SETTING IMPORTANT NOTE ! BE CAREFUL ! Once the password is set, it must be remembered, otherwise neither the frequency nor the password can be reset and the unit will have to be returned to Nicom for resetting. Display Change of Frequency. • Press the PROGRAM key for 3 seconds and enter the correct password. At this point press again the SELECT key: NEW PASS . = SET. NEW FREQ . = PRG .
When the new frequency is chosen, then press the SETTING key confirm it. After a “WAIT CYCLE”, the display will show the parameters: MOD > PW 1000W PR 0.4W PROGRAM SETTING After 7 minutes the display light will switch off and the display will show: NICOM MHz 103.
CHAPTER 2 ELECTRICAL SPECIFICATIONS NT 350 TECHNICAL DATA Power output: Frequency of operation: reference RF output connector/ Impedance: Frequency Stability: 5 to 350 Watts continuously variable Sinthesized with TXCO crystal N Type / 50 Ohms Better than 5ppm (± 500 Hz) , 0 to Frequency Range: 87.5 - 108 Mhz Frequency programming: Modulation type: S/N Ratio (ref. to 50 Khz / 1000 Hz): Distortion, THD: Asyncronous AM S/N ratio: 100% AM Digitally in 10 Khz increments.
Composite Total Harmonic Distortion Composite Intermodulation Distortion Baseband Crosstalk stereo subchannel SCA Inputs SCA Input Impedance SCA Input Levels nominal for SCA Amplitude Response Crosstalk subchannel >65dB measured in a 30 Hz - 100Khz bandwidth with 75 usec de-emphasis (RMS) 0.05 % typical 0.05 %, measured with a 1 Khz and a 1.3 Khz tone, 1:1 ratio, at 100% modulation 30 Hz - 60 Khz within 0.
MECHANICAL SPECIFICATIONS Chassis Dimensions: 132 mm (5.1") H 326 mm (12.83")D 445 mm (17.51) W Front panel dimensions: 483 mm (19") W 132 mm (5.1") H Ambient operating temperature: from 0 to + 50 C (+32 to +122 F) Humidity: 90% maximum, non condensing. Weight: 32 Lbs ( 14.
