The Rincon Research Corporation Model 2DC-70/4X is a two-channel, single-conversion frequency translator designed for interfacing standard 70-MHz intermediate frequency (IF) systems to high-speed, video analog-to-digital converter inputs.

 

 

Back Panel
 

Top View
 

Frequency Downconverter 2DC-70/4X

 
 

Description

Each channel independently downconverts a block of frequencies centered at the 70 MHz IF input to a selectable baseband center frequency.

Each channel provides four selectable bandwidths of 5 MHz, 24 MHz, 30 MHz, or 36 MHz. The baseband output center frequency may be selected in 250-KHz steps from BW/2 to BW/2 + 2.5 MHz (where BW = the selected channel bandwidth). Output spectrum can be selected to be inverting or non-inverting.

A programmable gain amplifier/attenuator at the input of each channel provides adjustment of the input signal amplitude over a +/-30 dB range in 1 dB steps. An output attenuator allows the output level to be attenuated up to 30 dB in 1-dB steps. Nominal conversion gain is +30 dB with input and output attenuation set to 0 dB.

Each channel provides two isolated outputs, each capable of driving 2 Volts p-p into a 50-ohm impedance. The outputs are DC coupled and have an auto-zero circuit which reduces DC offset and drift to less than +/-2 mV. Frequency response of the baseband outputs extends down to 1 Hz.

Low phase-noise synthesizers, phase-locked to a (required) external 10-MHz reference, supply local oscillator (LO) power. Each channel is phase coherent with respect to the input reference. A buffered 10-MHz reference output is available on the rear panel for daisy-chaining the 10-MHz reference to other devices. Buffered LO output ports on the rear panel are available for monitoring purposes.

Instrument status is indicated on the 4 x 40 character LCD on the front panel. Operation is via the 4 x 5 front panel keypad, guided by easy-to-follow, menu-driven instructions from the front panel display. Non-volatile memory preserves the last instrument status selected to prevent power outages from disturbing instrument settings.

An RS-232 port allows control of the instrument from a remote console. Front panel controls remain active.

In the event of an interruption of the 10-MHz reference input, a loss-of-lock indication is provided on the LCD display.

 

Specifications

 

General:

 Number of Input Channels 2
 Number of Output Channels 2 outputs per channel
 Input Center Frequency 70 MHz
 Output Baseband Center Frequency Adjustable in 250-KHz steps from channel BW/2 to channel BW/2 + 2.5 MHz
 3-dB Data Bandwidth Four selectable bandwidths: 5 MHz, 24 MHz, 30 MHz, or 36 MHz
 Conversion Gain +10 dB to +70 dB adjustable in 1-dB steps. Gain is +30 dB, nominal +/-2 dB with input and output attenuators set to 0 dB
 Amplitude Variation +/- 1.5 dB typical
 Amplitude Ripple +/- 0.25 dB typical
 Group Delay Variations TBD
 Phase Noise <3 degrees p-p, typical
 

Input:

 Input Level 0 dBm to -60 dBm
 Input Port Impedance 50 ohms
 Input Port Return Loss TBD
 Noise Figure TBD
 

Output:

 Output Level 2 Volts p-p, max.
 Output Port Impedance 50 ohms
 Output Port Return Loss TBD
 DC Offset < +/- 2 mVDC (output is auto-zeroing)
 Harmonic Distortion TBD
 Two-Tone IMD >35 dB down for two 2.0 Volts p-p output test tones (+10 dBm) with -30 dBm for each input signal with input and output attenuators set to 0 dB.
 Spurious Outputs TBD
 Image Rejection 35 dB typical, 30 dB minimum
 

External Reference:

 Input Frequency 10 MHz
 Input Level 0 dBm +/- 6 dB
 Input Impedance 50 Ohms
 Input Return Loss TBD
 

Physical Properties:

 Input / Output Connectors BNC
 Dimensions 17.07"W x 3.47"H x 19.5"D
 Weight 12 pounds (4.5 Kg)
 Temperature, Operating 0C to +50C
 Power (Standard configuration) 85-264 Vac 47-63 Hz, 60W