3dbm 70FMO-BS-2X-AYD 70 MHz FM Modulator Rackmount 115/230VAC BNC RF Out

3dbm 70FMO-BS-2X-AYD 70 MHz FM Modulator Rackmount 115/230VAC BNC RF Out

The 3dbm Inc. 70FMO-BS-2X-AYD is a rack-mounted 70 MHz FM modulator designed for satellite communications uplink chains. Built by 3dbm of Camarillo, CA, it accepts a baseband FM input signal and outputs a frequency-modulated carrier at 70 MHz — the standard intermediate frequency (IF) used in most VSAT and fixed satellite service (FSS) earth station transmit paths before the signal is upconverted to the final uplink frequency band. The unit provides front-panel Operate/Calibrate switching, a Peak Deviation analog meter, RF Monitor output, and alarm relay contacts for integration into larger satellite ground station systems.

Specifications & What's Included

• Manufacturer: 3dbm, Inc. — Camarillo, CA
• Model / Part Number: 70FMO-BS-2X-AYD
• Output Frequency: 70 MHz (standard satellite IF)
• Modulation: FM (Frequency Modulation)
• Power Input: 115/230VAC, Single Phase (1Ø), 47–63 Hz (dual voltage selectable)
• Fuse: 115V – 1A / 230V – 0.5A SB (fuse pull-type drawer on rear panel)
• Form Factor: Rack Mount (3U approximately; includes rack ears)
• Front Panel:
• AC Power switch (Off/On rocker)
• Peak Deviation analog meter (kHz scale)
• Operate and Calibrate adjustment controls (– / + trimmers)
• Operate/Calibrate illuminated mode switch
• Fault LED indicator (red)
• BNC RF Monitor output
• Voltage Monitor banana jacks: GND and +15V
• Rear Panel Connectors:
• J1 – RF Out (BNC)
• J2 – FM Mod In (BNC)
• J4 – Operate/Calibrate Select (DB9)
• J3 – Alarm relay terminal block: Common (A), N.O. (B), N.C. (D)
• Internal Sub-Modules (visible in photos):
• 3dbm Relay Enclosure module (labeled S/N 118)
• 3dbm 70 MHz FM Modulator module (labeled S/N 118) — with RF Mon and RF Out SMA ports
• Power supply assembly with toroidal transformer
• Main control PCB: ASSY.50886 (BD.50113L board)
• Internal RF interconnect cabling (SMA coax and ribbon)

Applications

70 MHz FM modulators are a core building block in satellite earth station transmit chains. In a typical satellite uplink setup, the baseband signal (audio, video, or data) is fed into the FM modulator at 70 MHz IF, and the resulting FM-modulated carrier is then passed to an upconverter and high-power amplifier before reaching the antenna. The 70 MHz IF standard was established across the satellite communications industry because it offered a practical compromise between component availability, filter selectivity, and upconverter design, and became nearly universal in VSAT hubs, broadcast uplinks, and fixed earth stations from the 1980s onward. Units like the 3dbm 70FMO are used in teleport and gateway earth station equipment rooms, government and military satellite communication sites, legacy broadcast uplink facilities, and anywhere a reliable 70 MHz IF modulator is needed for analog FM or SCPC (Single Channel Per Carrier) links. The dual-voltage 115/230VAC input makes the unit suitable for both domestic and international installations. The built-in Operate/Calibrate mode and alarm relay contacts support integration into monitored and remotely controlled ground station racks.