Comtech DT-4500 Series Down Converters

Overview
Our Down Converters are the ultimate in high performance and cost-effective Ku-Band frequency conversion. These can be used for SCPC, DAMA, and TDMA, as well as full transponder HDTV and analog TV. Spectral purity and stability characteristics fully meet or exceed the requirements of all domestic, international, and regional commercial satellite networks.

High Gain
Our Down Converters have +20 dBm minimum output level at the 1 dB compression point and 45 dB
of gain as a standard. This capability permits longer cable runs to the modem rack or compensates
for elaborate splitting networks without adding expensive options such as external line amplifiers.

Low Phase Noise
The phase noise performance exceeds the Intelsat phase noise mask for IBS and IDR services by
more than 9 dB. This allows phase dependent demodulators to perform better. The close-in phase
noise is very low, making the converter ideal for low bit rate digital circuits such as those used in DAMA hub earth stations.

Remote Control
The remote control interface is selectable between EIA-232 and EIA-485, as well as full Ethernet including Telnet, SNMP and preloaded HTML GUI. All configuration control, status retrieval, and adjustments are available as simple ASCII commands through the serial interface or through the front panel menu. As a cost option, the remote control command structure can be customized in order to accommodate existing network control software.

Detachable RF/IF Connector Module
Each converter is equipped with a detachable module that establishes input and output connections for the RF and IF paths. The module inserts into a rear compartment of the converter, and requires no additional outside space. The module includes SMA connectors for the RF path and BNC connectors at 50 or 75  for the IF path.

Daisy Chain Redundancy Switching
The converters use our patented "Daisy Chain” integrated switching technology. The Daisy Chain design removes the relays associated with a centralized protection switch tray and distributes them across the individual converters. Daisy Chain technology successfully eliminates a central switching chassis, two power supplies, a microprocessor, and several long, costly cables. Widely accepted in the industry, Comtech EF Data’s Daisy Chain provides both pricing and marketing advantages.

Minimum Rack Space
Due to its small rack height (1.75 inches) and the elimination of the space penalty paid for a separate 1+N switch chassis, the Down Converter and the Daisy Chain switch architecture provide the most compact and cost-effective converter subsystem available. The units are ideal for the construction of transportable systems such as “flyaways,” and high capacity earth stations where space utilization and economy are prime considerations.

Specifications
Available Models Frequency Range
DT-4503 3625 to 4200 MHz
DT-4503/C 3400 to 4200 MHz
DT-4503//D 3400 to 3700 MHz
DT-4503/E 4500 to 4800 MHz
DT-4510 10.95 to 11.70 GHz
DT-4510/D 10.70 to 11.70 GHz
DT-4511 11.70 to 12.20 GHz
DT-4512 12.20 to 12.75 GHz
DT-4512/E 12.50 to 12.80 GHz
DT-4513 10.95 to 12.75 GHz
DT-4513/E 10.70 to 12.75 GHz
DT-4572 (Legacy Model) 7250 to 7750 MHz
Conversion Dual, No Inversion
Step Size 125 KHz standard, 1 kHz optional
Preset Channels 32 Frequencies and Gains
Stability Over Time ± 0.5 x 10-9
/Day
Stability Over Temperature ± 1 x 10-8 0 to 50°C, Opt ± 5 x 10-9
RF Input
Input Level -45 dBm Typical
Return Loss 20 dB Minimum with I/O Module
Impedance 50 
Noise Figure 11 dB Maximum at 0 dB Attenuation
IF Output
Level +20 dBm at 1 dB Compression
Range 52 to 88 or 104 to 176 MHz
Optional 50 to 90 MHz or
100 to 180 MHz
(Contact factory with specific requirements
Non-Carrier Spurious -80 dBm
Carrier Spurious -65 dBc at 0 dBm Output
Intermodulation -60 dBc at 0 dBm Output SCL
Impedance 50 or 75 
Return Loss 23 dB Minimum
Transfer
Gain 45 dB ± 2 dB
Attenuation Adjust 0 to 20 in 0.25 dB Steps
0.1 dB Steps Optional
Gain Stability ± 0.25 dB/Day
Ripple ± 0.25 dB (± 18 MHz) Optional ± 20 MHz
0.75 dB (± 36 MHz) Optional ± 40 MHz
(Contact factory with specific requirements)
Slope 0.05 dB/MHz
Image Rejection -80 dB In-band
AM to PM 0.1°/dB for Output up to -5 dBm
IF Bandwidth 36 or 72 MHz, Optional 40 or 80 MHz
(Contact factory with specific requirements)
External Reference
Input, either 5 or 10 MHz Option @ +3 dBm
Optional 10 MHz Rear Panel Reference Output
Group Delay
Linear 0.03 ns/MHz
Parabolic 0.01 ns/MHz2
Ripple 1.0 ns Peak-to-Peak
Phase Noise
Limit (dBc/Hz) Typical (dBc/Hz)
DT-4503/X DT-4503/X
100 Hz -80 -83
1 KHz -89 -92
10 KHz -95 -97
100 KHz -105 -109
1 MHz -120 -124
Limit (dBc/Hz) Typical (dBc/Hz)
DT-451X DT-4513,
DT-4513/E
DT-451X DT-4513,
DT-4513/E
100 Hz -72 -66 -79 -69
1 KHz -79 -76 -82 -79
10 KHz -89 -86 -92 -89
100 KHz -98 -96 -101 -99
1 MHz -110 -106 -114 -109
Limit (dBc/Hz) Typical (dBc/Hz)
DT-4572 (Legacy Model),
DT-4503/E
DT-4572 (Legacy Model),
DT-4503E
100 Hz -69 -79
1 KHz -79 -82
10 KHz -89 -92
100 KHz -100 -102
1 MHz -110 -112
Remote Control (Rear Panel)
Comm Port RS-485 or RS-232C, RJ-45 for Ethernet
Indicators (Front Panel)
Power On Green LED
Mute Yellow LED
Remote Yellow LED
Reference Yellow LED
Stored Fault Red LED
Fault Red LED
Test Points (Front Panel)
RF Sample SMA, -20 dBc Nominal
IF Sample BNC, -20 dBc Nominal
Optional L.O. Sample
Power
Voltage 90 to 250 VAC Auto ranging, optional -48 VDC
Frequency 47 to 63 Hz
Dissipation 60 W
Environmental
Temperature 32 to 122°F (0 to 50°C)
Altitude 10,000 Feet MSL
Humidity 0 to 95% Relative Humidity
Physical
Dimensions (1RU)
(height x width x depth)
1.75” x 19” x 22”
(4.45 x 48.30 x 55.90 cm)
Weight 15 lbs (7.0 kg)
MTBF
49,740 hrs (calculated)
> 100,000 hrs. (field experience)
Summary Alarm
Relay Closure Form C