ELAD FDM-S3 SDR Receivers are outstanding Software Defined Radios with impressive performance features. The Italian manufacturer, ELAD, has pushed the boundaries of modern SDR design with this model. For instance, the FDM-S3 offers an incredible 24 MHz bandwidth that can be scanned simultaneously, allowing up to four receivers to operate at the same time—a feature typically reserved for much more expensive receivers. The FDM-S3 functions as a direct sampling SDR with a variable sampling rate of up to 122.8 MHz. It covers a reception range from 9 kHz to 108 MHz, with an optional downconverter available for even higher frequencies. One of the unique aspects of the FDM-S3 is its variable sampling rate, which ranges from 98 to 122 MHz depending on the band. This flexibility allows for more favorable divider ratios for down-sampling, enhancing sensitivity and dynamic range.

Another notable feature is the flexible selection of the clock source. The receiver is equipped with a TCXO (Temperature Compensated Crystal Oscillator) for accuracy and stability with moderate power consumption. Additionally, the FDM-S3 can be fitted with an optional GNSS (Global Navigation Satellite System) antenna, providing a frequency link to GNSS satellites (not included). An external 10 MHz reference clock can also be used from a high-precision source. The newly developed 'Reference Clock Manager Module' handles all clock signals and sources automatically, requiring no user intervention.

The FDM-S3 is equipped with two auto-switching low-pass filters and a bandpass filter for the 3m radio band. Up to eight additional low, high, and bandpass filters can be used, which are the same modules known from the ELAD FDM-S2R and ELAD QSF-06 Pre-Selector. It also features a switchable attenuator with three stages and a switchable pre-amplifier.

For shortwave, the FDM-S3 offers two switchable antenna inputs, one of which can provide a bias voltage for operating an external pre-amplifier. For VHF, there is one input available, also with switchable bias voltage. The receiver requires a Windows PC (Windows 7, 8, or 10, 32 or 64 bit) with sufficient power depending on the operation. Recording a 24 MHz wide spectrum, for example, requires considerable memory and data rates for the hard disk or SSD. More detailed information can be found in the manual. Power is supplied via Powerpole connectors, with a voltage range of 8-16 VDC, a power cable with Powerpole connectors pre-installed on one end is included.

The FDM-SW2 software is freely available on the internet for download, offering up to four independent decoders (receivers). This software can also be used to configure all receiver options such as band filters. Alternatively, the 'SDR Console' software by Simon Brown is also available as another great software option.

Additional Features and Specifications:

• Frequency Range: 9 kHz-108 MHz (over 108 MHz with the optional downconverter, see user manual for more information).

• Antenna Connectors: SMA connectors. Two for HF (up to 54 MHz) and one for VHF (up to 108 MHz). One RF-IN connector if the downconverter option is present (above 108 MHz).

• It has two antenna biases, one for an HF input and one for the VHF input (or for the RF-IN input).

• Computer Interface: USB 3.0 High-Speed (see requirements in user manual).

• Power Requirements: 8.0-16.0 VDC (not included).

• Dimensions (W x H x D) 9.060 x 2.362 x 6.102 in. (230 x 60 x 155mm)

• Weight: 4.74 lbs. (2.15kg) without internal Downconverter