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Table of Contents
Summary of Contents for Greenlee Communications 77M-G
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Page 2: Safety Alert Symbol
SAFETY ALERT SYMBOL This symbol is used to call your attention to hazards or unsafe practices which could result in an injury or property damage. The signal word, defined below, indicates the severity of the hazard. The message after the signal word provides information for preventing or avoiding the hazard. - Page 3 Electric shock hazard: • Do not expose this unit to rain or moisture. Contact with live circuits could result in severe injury or death. • Use this unit for the manufacturer’s intended purpose only, as described in this manual. Any other use can impair the protection provided by the unit.
- Page 4 A three-position toggle switch controls the modes of operation, and bi-colored Light Emitting Diodes (LEDs) display line polarity for Lines 1 and 2 (Line 1 only for 77M-G). When a short circuit is detected, an audible signal will be heard (77HP only). The tone and short circuit test functions are only applied to Line 1 using the modular plug.
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Page 5: Purpose Of This Manual
(as described) or the modular plug. Note: When using the modular test plug, the polarity test function applies to Lines 1 and 2 USOC (Line 1 only for 77M-G). The continuity and tone functions only apply to Line 1. - Page 6 Identifying Tip and Ring (Polarity Test) Telephone service must be present to perform this test. In the OFF (4 VOLTS) position, connect the black test lead to ground and the red test lead to each side of the line to be tested. •...
- Page 7 Supplying Talk Power Connect the test leads in series with a telephone test set (buttset) and the inactive wire pair (Figure 2). Move the toggle switch to the SHORT position to supply the “dead” line with talk power. Additional test sets may be added, in series (red clip to black clip), to increase talk power supply when needed (Figure 2).
- Page 8 Sending Tone With the test set in the TONE position, connect the modular plug or the red/black leads to the subject wire(s). An internal slide switch (accessible from the outside using a slender tool) allows the selection of either a fast or slow warble tone output (Figure 3).
- Page 9 identified, separate the two wires. The signal will be as loud on each of the pair wires and will NULL halfway between the two wires. Figure 4a. Cable Tracing Figure 4b. Pair Tracing Reception of tone will be strongest on the subject wire(s). Shorting the leads of a tone carrying wire pair will cancel the tone signal and also confirm that the pair has been identified.
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Page 10: Specifications
Specifications Electrical Talk Battery (into 600 Ω): 4.6 VDC Output Power (into 600 Ω): +10 dBm Resistive Short Visual Indication: <10 kΩ Resistive Short Audio Indication (77HP-G and 77HP-G/6A only): <200 Ω Output Frequency (nominal): Tone: Alternating 890/960 Hz Warble Rate: Slow: 1.3 Hz Fast: 6 Hz Voltage Protection (into a 600 Ω... -
Page 11: Maintenance
Maintenance Electric shock hazard: Before opening the case, remove the test leads from the circuit and shut off the unit. Failure to observe this warning could result in injury and can damage the instrument. Battery Replacement 1. Remove screw from rear of set holding back cover. 2. - Page 12 Edited by Bo Edin AB 2018 One-Year Limited Warranty Greenlee Textron Inc. warrants to the original purchaser of these goods for use that these products will be free from defects in workmanship and material for one year, excepting normal wear and abuse. For all Test Instrument repairs, you must first request a Return Authorization Number by contacting our Customer Service department at: toll free in the US and Canada 800-642-2155...
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