AARON FM/HD Radio™ Rebroadcast Receiver Model 655

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  • Regular price $2,900.00

FM/HD Radio™ Rebroadcast Receiver

The AARON 655 employs a sensitive FM / HD Radio™ SDR-based receiver that invariably returns to the programmed frequency and reception mode following a power interruption. In addition to FM and HD1-8 program sources for rebroadcast, the 655 accepts analog, AES-digital and streaming program inputs with fallback-priority selection. Outputs are FM-stereo-multiplex (MPX) as well as both analog and AES digital program line outputs and output streaming.

IP connectivity with a Web-browser interface permits total remote control of the unit from any PC or mobile device, along with remote audio monitoring. Local GPIO failure alarms are augmented with email notifications, alarm logs, and full support for SNMP operation.

Comprehensive audio processing includes gated and ‘windowed’ AGC, a unique ‘syllabic’ leveler, three bands of compression, and both wideband and independent HF limiting. 4 sections of parametric EQ, a ‘Bass Punch’ utility, independent Density and Loud/Smooth adjustments, and variable composite processing round-out the processing function. The AARON 655 includes an onboard RDS encoder that can either pass or regenerate incoming RDS, and can also reformat HD Radio™ ‘PAD’ data for RDS retransmission.


  • Uncompromising DSP-based (SDR) receiver performance

  • Accepts program audio from analog FM, digital HD1 through HD8 programs, streaming sources and analog or AES-digital line inputs, all with assignable failover audio backup

  • Audio processing with AGC, parametric EQ, bass ‘punch’ enhancement, multiband compression, independent broadband / HF peak control and composite clipping

  • A regenerated and peak-controlled composite/MPX output, plus balanced analog and AES-digital program line outputs for exciters with built-in stereo generators

  • An internal RDS/RBDS encoder that can customize incoming off-air RDS data, convert HD Radio™ PAD to RDS, convert streamed metadata to RDS, or receive IP Telnet data

  • An intuitive remote-control Web Interface with remote audio monitoring; self-logging reception alarms give instant email and text notification

  • SNMP remote monitoring and control of all AARON 655 functions

  • A built-in BandScanner™ for a snapshot of the local RF spectrum



Tuning Range

87.5MHz - 107.9MHz in 100kHz steps

Sensitivity/Noise Performance

5dBμV for 50dB unweighted, monaural analog-FM SNR

Off-Air Frequency Response

  • Analog-FM: ±0.5dB, 20Hz - 15kHz
  • HD Radio™: 20Hz - 20kHz (per certification spec.)

FM De-Emphasis

5μs or 50μs, menu-selectable

Stereo Separation (at 1kHz)

  • Analog-FM: >50dB
  • HD Radio™: >90dB

Radio Data System

  • Analog-FM: RDS/RBDS, menu-selectable
  • HD Radio™: “PAD”

Program Signal Latency (Delay)

  • Analog-FM or Line-In Sources: 3.7ms to analog line out, 4.53ms to digital line out, 4.1ms to MPX out
  • HD Radio™ Source: typically 8 seconds to any output


Antenna Input

50Ω (N)

Composite/MPX Output

75Ω (BNC); 1V p-p - 6V p-p for ±75kHz FM carrier deviation

Program Line Inputs

  • Analog: Active-balanced (XLR) accepts ‘0VU’ line levels between –15dBu and +15dBu; +24dBu clipping
  • AES Digital: Balanced (XLR) accepts peak line levels between –30dBFS and 0dBFS at sampling rates between 32kHz and 96kHz
  • IP Streaming: Accepts Icecast/SHOUTcast MP3, Ogg and AAC streams

Program Line Outputs

  • Characteristic: Analog and digital program line outputs may be switched between FM-pre-emphasized or ‘normalized’ (flat) response
  • Analog: Active-balanced (XLR) delivers –12dBu to +18dBu at 100% modulation; +18dBu clipping; 200Ω source
  • AES Digital: (XLR) 24-bit, 44.1kHz sampling; delivers –30dBFS to 0dBFS at 100% modulation
  • Streaming: MP3-encoded for remote IP/browser monitoring

Network Port

RJ45 jack TCP/IP network connection for complete remote setup and operation of the AARON 655; supports SNMP


4 GPI, 6 GPO screw-terminal connections, all assignable with selectable logic polarity; enable contact-closure control of certain setup and operating functions and provide local external alarm tallies or connection to remote control systems

Headphone Jack

¼-inch front-panel (TRS)


Four progressive (sequential) failovers may be selectively programmed to respond to carrier loss, audio loss, FM pilot loss, HD loss, stream loss or RDS mismatch as appropriate to the source fault.



Gated, ‘gain-riding’ AGC with ±15dB capture range; dualrate ‘windowed’ operation


Variable ‘syllabic’ 2:1 compression normalizes dialog and music sources

Parametric Equalization

4-sections of parametric EQ, each with variable frequency, ‘Q’ and gain

Bass ‘Punch’

Variable bass enhancement accents the initial bass attack


3-bands of r.m.s. and peak compression with selectable crossover frequencies, variable master and individual band drive controls

Final Peak Control

Feed-forward final peak limiting eliminates flat-top clipping; independent HF limiter for pre-emphasis protection

Composite Clipper

0dB - 3dB adjustable MPX clipping depth (excludes stereo pilot and RDS subcarrier)

Processing Presets

10 factory, 10 user-defined presets


Fields Supported



HD Radio™ Name, Slogan, Artist, Title, Album and Genre may be converted to the RDS scrolling-PS and RT fields

Streaming Audio Metadata to RDS

Streamed Name, Metadata, Description and Genre may be converted to the RDS scrolling-PS and RT fields

Telnet to RDS

Accepts dynamic PS and Radio Text updates via IP


A built-in spectrum analyzer utility sweeps the entire FM band (or a selected portion) and presents a graphic display of all signals received, includinag RSSI values and HD Radio™ transmissions.



Fault alarms include radio audio loss, analog audio loss, digital audio loss, stream audio loss, low signal, RDS error, stereo pilot loss and HD Radio™ channel loss. Alarms trigger front-panel indications, local (GPO) closures, browser interface notations, SMS/email dispatches, SNMP.

Alarm Logs

Alarms are logged and may be downloaded as daily, weekly or monthly CSV files.


All setup and operating controls and alarm functions of the AARON 655 are under SNMP management.

Internal Test Tone Generator

20Hz - 20kHz; programmable frequency and amplitude

Power Requirement

88VAC - 264VAC, 48Hz - 63Hz (‘universal’); 12 watts

Size and Weight

H: 1¾”/44mm, W: 19”/483mm, D: 9½”/240mm (1U); 9lb/4kg (net, 12lbs/5.4kg (shipping)


32°f/0°C - 122°F/50°C; 0% - 95% non-condensing relative humidity; 10,000ft/3048m

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