Eddystone Model 1680 MF/HF Receivers

General Description

The 1680 series of receivers are designed for crystal locked operation in commercial service.

Model 1680/1A is designed for single channel use in the frequency range 400kHz - 535kHz, modified to suit the requirements of OTC Australia. Model 1680/3 is a single channel receiver and model 1680/4 is a dual channel receiver, both capable of covering the frequency range 1.6 Mhz - 30 Mhz on AM/SSB, given the fitment of appropriate front end modules.

The sets are designed to operate from 100/130 & 200/260V AC or from a 24VDC negative earth supply.

The IF frequency is 1400 kHz, Dual diversity operation is possible.

Remote control of all functions is available.

AM and USB are usually provided.

Aerial input is 50 ohms unbalanced.

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Technical Data

TYPICAL SPECIFICATIONS

Sensitivity: 1 micro-volt for 12db SINAD on SSB
Selectivity: USB -6db +350Hz to +2700 Hz
                             -60db -400Hz to +3400 Hz
                   AM    -6db +- 3.0kHz
                             -60db +- 7.5kHz
Image Rejection: Greater than 50db above 20 MHz
                              Greater than 70 dB below 20 MHz
IF Rejection: Greater than 90db
Audio Output: Line 600 ohm bal/unbal to +10 dBm max
                         Headset 600 ohm nominal to + 10 dBm max
                         Loudspeaker 2 watts max.
                         External Loudspeaker 2 watts max into 8 ohms
Stability: Within 20 Hz over temperature range 0 - 40 degrees C.