Model 2A Operation And Service Manual 2A Off Air Frequency Standard OPERATION & SERVICE MANUAL 2A Manual A5 21 January 2005 Page 1
Model 2A Operation And Service Manual Contents Safety Considerations......................................................................... 3 Voltage, Frequency and Power Characteristics ................................. 4 Environmental Conditions................................................................... 4 Replaceable Fusing Characteristics ................................................... 4 Cleaning Instructions ..........................................................................
Model 2A Operation And Service Manual Safety Considerations General This product and related documentation must be reviewed for familiarisation before operation. If the equipment is used in a manner not specified by the manufacturer, the protection provided by the instrument may be impaired. Before Applying Power Verify that the product is set to match the available line voltage and the correct fuse is installed. Before Cleaning Disconnect the product from operating power before cleaning.
Model 2A Operation And Service Manual WARNING Any interruption of the protective grounding conductor (inside or outside the instrument) or disconnecting of the protective earth terminal will cause a potential shock hazard that could result in personal injury. Grounding one conductor of a two conductor outlet is not sufficient protection. Whenever it is likely that the protection has been impaired, the instrument must be made inoperative and be secured against any unintended operation.
Model 2A Operation And Service Manual Cleaning Instructions To ensure long and trouble operation, keep the unit free from dust and use care with liquids around the unit. Be careful not to spill liquids onto the unit. If the unit does get wet, turn the power off immediately and let the unit dry completely before turning it on again. Clean with a damp (with water) cloth. Never spray cleaner directly onto the unit or let liquid run into any part of it. Never use harsh or caustic products to clean the unit.
Model 2A Operation And Service Manual Please ensure aerial is connected before applying mains power to the unit Please allow typically 1 minute for phase lock loop to settle As from 01.02.99 all units have been modified to be "Year 2,000 Compliant" - Y2K and to conform with the latest "CE" marking regulations - EMI, EMP, EMC, RFI, etc.
Model 2A Operation And Service Manual Model 2A Off Air Frequency Standard Getting Started- Some Useful Notes 1. 2. Connect a mains lead to the IEC socket on the rear panel- first ensuring that the mains “SUPPLY" switch is in the "OFF" position. This indicates that the unit is receiving no mains power. Also ensure that the "ON-OFF" knob on the front panel is also in the "OFF" position.
Model 2A Operation And Service Manual General description 1. Receivers These frequency standards are intended for indoor use and operate on LF or VLF frequencies, within the reception range of suitably stable, high-power, long wave transmitters. This range often exceeds 2500 km. Many such transmitters are locked and/or are traceable to well recognised national frequency standards via published data "post facto".
Model 2A Operation And Service Manual Even for a FSD temperature change, the rate of internal temperature rise, and hence the phase rate (=frequency error) is limited, partly by the thermal mass and its inertia and by the low drift coefficient. Such receivers do still suffer from several effects, which cause degradation of the accuracy of the output frequency, these include the following effects: a. Possible transmitter outages: maintenance, severe weather, and power failure. b. Temporary local RFI.
Model 2A Operation And Service Manual 2. The Loop Aerial The loop aerial supplied with all units has been found to be the best type available for this application, achieving excellent temperature performances with no significant phase effects. (In comparison, ferrite rod aerials are very temperature sensitive and will contribute significantly to the phase noise in the system).
Model 2A Operation And Service Manual 2A Manual A5 21 January 2005 Page 11
Model 2A Operation And Service Manual 2A Manual A5 21 January 2005 Page 12
