DRAKE VM1550 Gebrauchsanweisung - Seite 5

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RF
Frequency Range:
54 - 348 MHz.
Channels Available:
VHF 2-13,
Lowband 1 (A8)
Midband 14-22 (A-I) and
95-99 (A5-A1),
Superband 23-36 (J-W),
Hyperband 37-44 (AA-HH)
Factory tuned for single
channel. *
Output Level:
+45 dBmV minimum, (typically
adjustable from +35 to
+45 dBmV). Note: If an output
level of less than +35 dBmV is
required, add an attenuator of
the appropriate value to the
modulator output.(eg., add a
10 dB pad for +30 dBmV output).
Output Impedance:
75 Ohms, return loss of 12 dB.
A/V Ratio:
Audio Carrier -20 to -12 dB
referenced to video carrier,
adjustable.
Frequency Stability:
± 5 kHz (Visual Carrier).
Intercarrier Frequency:
4.5 MHz.
FCC Frequency
Offsets:
All aeronautical channels
offset positive with a tolerance
of ±5 kHz.
Spurious Outputs:
-65 dBc minimum, measured
at -15 dB A/V ratio and with
modulator output level of
+45 dBmV.
Broadband Noise:
-77 dBc, referenced to video
carrier.
(4 MHz BW @ ±12 MHz offset).
-95 dBc @ ±36 MHz 0ffset.
VIDEO
Input level for 87.5%:
1 Vp-p +/-3 dB, manual gain
adjust with front panel control.
Over-Modulation LED set for
87.5% depth of modulation
indication.
Input Impedance:
75 Ohms, return loss of 18 dB
minimum.
Frequency Response:
20 Hz to 4.2 MHz, ±1.0 dB.
*Consult factory for custom channels

Specifications

Video S/N:
60 dB minimum,
luminance weighted.
L/C Delay:
±35 nSec referenced to 0 nSec
L/C delay (complies with FCC
rules, 76.605).
Differential Gain:
± 4% (10 to 90% APL).
Differential Phase:
± 4 degrees (10 to 90% APL).
AUDIO
Input Level for 25 kHz
Peak Deviation:
140 mV minimum. Manual gain
adjustment with front panel
control. Over-Modulation LED set
for 25 kHz peak deviation
indication.
Input Impedance:
10K Ohms, Unbalanced.
Pre-emphasis:
75 Sec. (internally defeatable).
Frequency Response:
20 Hz to 15 kHz, ± 1 dB,
referenced to 75 Sec
pre-emphasis curve.
(20 Hz-100 kHz if preemphasis
is defeated).
4.5 MHz Intercarrier
Stability:
±5 kHz, 0
Total Harmonic
Distortion:
1.0% maximum.
Hum and Noise:
-60 dB minimum, referenced
to 25 kHz peak deviation.
COMPOSITE IF
LOOP
Output Level (V carrier):
+28 dBmV.
Input Level (V carrier):
+28 dBmV.
Input/Output
Impedances:
75 Ohms.
GENERAL
AC Power Input:
115 VAC ±10%, 60 Hz,
10 WATTS.
Operating Temperature
Range:
0
0
Size:
19" W x 1.75" H x 6.75" D.
Weight:
5 Lbs. (2.25 Kg).
5
0
C to +50
0
C.
C to +50
0
C, ambient.