Related Manuals for Timewave DM-1
Summary of Contents for Timewave DM-1
- Page 1 DM-1 Deviation Meter Operating Manual Timewave Technology Inc. 1025 Selby Ave. St. Paul, MN 55104 http://www.timewave.com August 1997...
- Page 2 © 1997 by Timewave Technology Inc. All rights reserved. Copyright Notice This document and all software or firmware designed by Timewave Technology Inc. is copy- righted and may not be copied or altered in any way without prior written consent from...
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Page 3: Table Of Contents
DM-1 Operating Manual / iii Table of Contents Introduction ....................1 Features ........................1 Specifications ......................2 Operation ....................3 Battery Installation ....................3 To Turn On ....................... 3 Selecting a Deviation Range ..................3 Connections ......................4 Measuring Deviation ....................4 Calibration .................... - Page 4 / DM-1 Operating Manual This page intentionally left blank.
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Page 5: Introduction
FM transmitters operating in the 140, 220 or 440 MHz. amateur bands. Even though the DM-1’s functions are straightforward and easy to use, please read through this manual. The following pages contain some excellent notes and tips to help you get the most from your Deviation Meter. -
Page 6: Specifications
2 / DM-1 Operating Manual Specification Frequencies: 147.9 MHz., 222.1 MHz., 444.1 MHz. Deviation Ranges: ± 1 kHz.; ± 5 kHz. full scale Readout: 10 segment LED bar and provisions for external meter Deviation resolution (LED): 50 Hz. on 1 kHz. range;... -
Page 7: Operation
Battery installation Turn the DM-1 Deviation Meter off before installing a battery. Two screws (one on each side of the DM-1) allow access to the battery compartment. Use one standard 9-volt alkaline battery. Replace the screws on the sides of the Deviation Meter and battery installation is complete. -
Page 8: Connections
Connect your transmitter to the INPUT coaxial connector on the DM-1, and the antenna to the OUTPUT connector, using adaptors if necessary. (If it is more convenient, you can swap the input and output cables.) Insertion loss and SWR are low enough that the DM-1 may be left in the line if desired. -
Page 9: Calibration
The next steps require the use of a calibrated frequency-modulated signal source of either 100 kHz., 74.1 MHz., or one of the three frequencies printed on the front of the DM-1. Connect the signal source to either the INPUT or OUTPUT connector on the DM-1. -
Page 10: Circuit Description
6 / DM-1 Operating Manual Circuit Description Radio frequency enters the DM-1 either directly through the WHIP input J1 or the stripline coupler between coaxial connectors J2 and J3. The stripline coupler provides 20 - 30 dB. of attenuation to the input signal, depending on frequency. The signal is limited by diodes D1 and D2 to prevent damage to mosfet mixer Q1, with the remaining voltage getting dropped across R30. - Page 11 DM-1 Operating Manual / 7 Bargraph driver U3 displays the output voltage of U4B, which is proportional to the peak deviation. To provide double the resolution of the bargraph, the display is dithered by injecting a 60 mV. square-wave derived from U5. The forward voltage drop of D10 provides adequate regulation of this signal.
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Page 14: If You Need To Call For Help
Label) takes 7-10 days to reach us depending on your location, Blue takes 2-3 days. Red is an overnight service and is expensive. Send the DM-1 in a way that it can be traced if we can’t verify receipt of shipment. We suggest UPS or insured postal shipment. -
Page 15: Warranty
Timewave Technology Inc. products carry the following warranty: Timewave hardware products are warranted against defects in materials and workmanship. If Timewave receives notice of such defects during the warranty period, Timewave shall, at its option, either repair or replace hardware products which prove to be defective. - Page 16 12 / DM-1 Operating Manual This page left intentionally blank.
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