1. GENERAL
DESCRIPTION
The model NRD-91 Receiveris a highly reliable receiverwith the simple circuit com-
position, developed
by JRC based
on our many year'sexperimentand technicalresults.
PLL
syuthesizeris equipped in the first local oscillator to prvode the high accuracy of frequency
setting,so that this receiver
hasenoughperformances
for usein the SSBmode as a back-up
receiver.
1.1 FEATURES
I
) Provided
with digital
synthesizer
of PLL type
The reference
oscillator
with the highstability(t5 x l0-6ppm) ensures
highstabilityof
fiequencies
overa wide frequencyrange
for reception.
2) Wide
receivingfrequencyrange
Thisreceiver
covers
the wide receiving
frequencyrange
from 90 kHz to 29.9999MHz.
3) Digital
indication
of receiving
frequencies
This receiver is provided with light emitting diodes for a numerical display of the
receiving
frequency
from 100
Hz digit to l0 MHz digit.
Therefore,
the frequencycanbesetcorrectly.
4) BCband
rejector
BC bandrejector
reduces
theinterferences
such
as
cross-modulation
andintermodulation
due to the strong radio waveof the broadcasting
wavegenerating
during receivingthe
MHF radiowave.
5) Directlyconnected
to Teleprinter
andFAX
The line output terminal,
600St
0 dBm,isprovided.
By addingtheoptional crystal,FSk
or FAX canbereceived
in the AUX mode.
At thistime, the center
frequency
of the line
output is 1.7
kHz and l.9 kHz respectively.
6) Entirely modular
construction
The circuits are accomodated
in the plug-in type printed circuit boards(excluding the
panel
section
andpower
supply
unit). Thus,maintenance
andcheckare
facilitated.
1) Operable
on either
AC or DC power
The receiver
canbe operated
on AC or DC power
by changing
the powerswitch
on the
panel.
1.2 SPECIFICATIONS
I
) Receivingfrequency
range
9OkHz to 29.9999
MHz
2) Circuitsystem
Double superheterodyne with up-conversion
system using a phase-locked
digital
frequency
synthesizer.
Ist
lF- : 70.45
5 MHz
2ndIF : 455kHz
3) Reception
mode
CW(AlA), MCW(A2A,
HzA), DSB(A3E),
SSB(R3E,H3E, J3E) andFSK(FlB) or FAX
(F3C)
,2-
