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DANIELS 

 

ELECTRONICS LTD. 

®

 

 

 

MT-3 RADIO SYSTEMS 

 

 
 
 
 

VHF TRANSMITTER

 

INSTRUCTION MANUAL

 

VT-3 

29 - 50 MHz

 

 
 

Covers model: VT-3H035-SWA3,  VT-3H045-SWA3  

 

 

 

 

 

 

Copyright  ©  1997  Daniels  Electronics  Ltd.    All  rights  reserved.    No  part  of  this  publication  may  be 

reproduced,  stored  in  a  retrieval  system  or  transmitted  in  any  form  or  by  any  means,  electronic, 

mechanical,  photocopying,  recording  or  otherwise,  without  the  prior  written  consent  of  Daniels 

Electronics Ltd. 

 

 

 

 

 

 

Issue: 

Previous Issue: 

N/A 

Issue Date: 

May 97 

Previous Issue Date:  N/A 

Daniels Electronics Ltd. 

Printing Date:  Sept 97 

 

Victoria, B.C. 

Part No.: 

IM20-VT3040   

PRINTED IN CANADA 

Summary of Contents for VT-3H040

Page 1: ...art of this publication may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording or otherwise without the prior written consent of Daniels Electronics Ltd Issue 1 Previous Issue N A Issue Date May 97 Previous Issue Date N A Daniels Electronics Ltd Printing Date Sept 97 Victoria B C Part No IM20 VT3040 PRINTED IN CANADA ...

Page 2: ...ization The organization of this manual reflects the modular makeup of the VT 3 product line Each module is fully described within its respective submanual all of which are contained within this document In general each submanual contains 1 A functional description and specification summary 2 a detailed technical description Theory of Operation and 3 assembly setup and alignment procedures releven...

Page 3: ... VT 3H040 line of transmitters has a single RF power output rating of 3 0 Watt with wide band FM 20 kHz or 25 kHz channels and employs synthesizer based frequency generation The two basic i e no options added band specific models of the transmitter are as follows VT 3H035 SWA3 29 MHz to 38 MHz VT 3H045 SWA3 38 MHz to 50 MHz The frequency is determined by the model of synthesizer and by the lowpass...

Page 4: ...Type N connector Duty Cycle 100 Continuous operation from 30 C to 60 C optional 40 C to 60 C Harmonic Emissions More than 90 dB below carrier Spurious Emissions More than 80 dB below carrier Transmitter Mismatch Protection 20 1 VSWR at all phase angles Transmitter Alarm Forward power sense and reverse VSWR open collector output separate or OR ed linear output separate lines only Modulation 16K0F3E...

Page 5: ...ure Range 30 C to 60 C optional 40 C temperature test Operating Humidity 95 RH non condensing at 25 C Operating Voltage 13 8 Vdc Nominal range 11 to 16 Vdc 9 5 Vdc Regulated Total Transmit Current 0 8 Amp typical 1 2 Amp maximum Front Panel Controls NORM repeat mode OFF and KEY TX Tx on PTT Activation Active to ground with or without time out timer Microphone activated with or without time out tim...

Page 6: ...z with a 1 kHz tone Subtone Audio Input 1 0 5 Vpp at 200 Hz for 500 Hz deviation internally adjustable Subtone Audio Input 1 Frequency range 60 Hz to 300 Hz Subtone Audio Input 2 0 5 Vpp at 100 Hz for 500 Hz deviation internally adjustable Subtone Audio Input 2 Frequency range DC to 150 Hz Direct Modulation Input 0 5 Vrms at 1 kHz or 3 kHz deviation Direct Modulation Frequency range DC to 5 kHz Au...

Page 7: ...odules mate with Daniels standard M3 repeater subrack Subracks modules comply with IEEE 1101 DIN 41494 and IEC 297 3 mechanical size modular arrangement External Connections RF Connection type N connector located on the transmitter module front panel Motherboard Connections Audio Power and Control are made through a 48 pin gold plated type F connector on the rear of the transmitter module User con...

Page 8: ...n by the transmitter in its quiescent state depends on what modules are enabled during the inactive PTT off state This aspect of transmitter operation is controlled by jumper settings on the Transmitter Main Board refer to the Transmitter Main Board Manual The minimum 9 5 Vdc quiescent current is typically 15 mA and occurs when the Synthesizer and Audio Processor are disabled while the transmitter...

Page 9: ...5000 or Txfrequency CHNL 5000 kHz MHz 6 25 x 29 Alternatively a frequency and channel lookup table is available in the Channel Designation Table manual for the VT 3H040 A channel can be selected from a set of 15 maximum possible factory programmed channels by the four channel select lines available at the rear F connector on the Transmitter Main Board A single user selectable channel is set by swi...

Page 10: ...n 2 2 of this manual Transmitter Main Board Manual 2 Synthesizer Synthesizer Manual 3 Amplifier Amplifier Manual 4 Audio Processor Transmitter Main Board Manual 2 3 2 Frequency Change The transmitter is initially aligned at the factory for the frequency stamped on the Factory Set Operating Frequency label see section 3 1 This label should list the frequency at which the last complete transmitter a...

Page 11: ...nge between 0 2 and 0 5 MHzTransmitter Main Board Channel Change Audio Processor see section 2 3 4 between 0 5 and 1 0 MHzTransmitter Main Board Channel Change Audio Processor see section 2 3 4 check RF alarm thresholds section 2 3 5 1 0 MHz or greater Complete alignment NOTE May not be applicable to all installations 2 3 3 Output Power Adjustment The RF power output of the amplifier is set to its...

Page 12: ...ustment should not be affected by a change in frequency or deviation settings 2 3 5 Setting RF Alarm Thresholds The VSWR and Forward Power Alarms are factory preset to give alarm conditions for a 3 1 VSWR and 50 forward power respectively The Amplifier Manual describes how to adjust these settings should different levels be required If the alarm thresholds are crital to operation of a particular i...

Page 13: ...r Jumpers it is recommended to use solder braid in place of manual vacuum type desoldering tools when removing jumpers This will help prevent damage to the circuit boards 2 6 Printed Circuitboard Numbering Convention To ease troubleshooting and maintenance procedures Daniels Electronics Limited has adopted a printed circuitboard PCB numbering convention in which the last two digits of the circuitb...

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