Electro-Metrics EM-2115, Инструкция по эксплуатации

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EM-2115 APPENDIX C FUNCTION AND DESCRIPTION
(EM2115C-3)
The IG Calibrator is controlled by logic comands from the Microprocessor Assembly
(A1A3).
C-4.3 A2A16A1 Stator Board Assembly
(Refer to Figure H.2)
The Stator Board Assembly and 15 RF Frequency Range Bands comprise the active tun-
ing circuitry of the receiver. The Stator Board Assembly interfaces with the RF Frequency Range
Bands, mounted on a motor-driven rotor, through spring contacts on one edge of the assembly.
For RF Frequency Range Bands 1-9 (9 kHz-12.5 MHz), the Stator Board contains the RF
tuning and LO (Local Oscillator) circuitry. The tuning and LO circuitry use voltage variable ca-
pacitors (varactors) to tune each circuit to the selected RF signal. The RF and LO signals are ap-
plied to a mixer stage producing either a 175 kHz or 1.6 MHz IF output.
RF Frequency Range Bands 1, 2, 6, and 7 produce a 175 kHz IF output. RF Frequency
Range Bands 3-5, 8, and 9 produce a 1.6 MHz IF output. Frequency Range Bands 3-5 are double
converted, the first IF is 1.6 MHz with the final conversion to 175 kHz accomplished on the Pre-
amplifier/Tuning Regulator Board.The IF produced by the mixer stage is applied to the Preampli-
fier/Tuning Regulator Board (A2A16A2).
For RF Frequency Range Band 10 (12.5-30 MHz), only the LO circuitry on the Stator
Board is used. A 1.6 MHz IF output is produced and applied to the Preamplifier/Tuning Regula-
tor Board (A2A16A2).
For RF Frequency Range Bands 11-15 (25 MHz-1 GHz), the only circuitry located on the
Stator Board Assembly is a high frequency mixer stage. Both the RF and LO signals are supplied
from the RF frequency range band. The final 8.7 MHz IF output produced by the mixer stage is
applied to the Preamplifier/Tuning Regulator Board (A2A16A2).
The high voltage tuning voltage for the RF and LO tuning circuits on the Stator Board
and upper frequency range bands is supplied by the Preamplifier/Tuning Regulator Board
(A2A16A2).
C-4.4 A2A1-A2A15 RF Frequency Range Bands
(Refer to Figures H.3 thru H.9)
The RF Frequency Range Bands comprise the active tuning circuitry in conjuction with
the Stator Board Assembly (A2A16A1).