Receiver and Software Defined Radio (SDR)

FDM-S2  New 

Elad SDR FDM-S2

SDR HF/VHF receiver

FDM-S1 SDR Receiver (Software Defined Radio) with DRM function


Compact SDR Receiver with DRM, range up to 30 or 170MHz!

Elad (Italy) does offer various SDRs for several years. Based on this experience the FDM-S1 was designed as a very compact receiver with many outstanding features. The low power consumption of just 2.2W makes the FDM-S1 an ideal travel companion for your notebook computer. Optionally partially populated boards are available, offering place for many own experiments and improvements.

Like most Hi-End SDRs the receiver uses a direct sampling of the HF radio spectrum, with a sample rate of 61.44 MHz. The signal is analog/digital converted with a 14 bit ADC and processed digitally. The connection to the computer is done with a high speed USB 2.0 cable.

The standard receiving range is from 20 kHz up to 30MHz. When using the 'undersampling' function, the receiving range is extended up to 170MHz, albeit with reduced specifications. A maximum spectrum width of 6.144 MHz can be displayed. As usual with SDRs this spectrum can be recorded and later be used for further analysis.

A special feature of the FDM-S1 is the integrated DRM decoder. Without the need of additional software installation, DRM transmissions can be decoded out of the box. That is much easier than with other SDRs. Of course the FDM-S1 can decode all other standard modes as well: U/LSB, DSB, CW, AM, Synchron-AM, FM, W-FM etc.

The filter width can be set very precisely and individually per mode. And here it is where the experience of the manufacturer Elad shows: even with the smallest filter width setting of 100Hz no ringing can be heard.

Included in shipment is the software FDM-SW1, which offers clean looks, comfortable operation and many inventive features. The patent pending tuning system offers three mouse operated dials fpr 'coarse', 'middle' and 'fine' tuning, resulting in a very precise and fast tuning over the entire range. But tuning can be done very nicely with the keyboard as well. A directly accessible recorder allows storage of received transmissions with a click of the mouse.

Further the FDM-SW1 software allows to define an indefinite number of band segments, where mode, filter and tuning steps are pre defined. Each frequency can be stored in memories, only limited by disk storage space. A transmission schedule for DRM is supplied with the software.

Instead of the supplied software other programs can be used as well. The FDM-S1 works also with the "Studio1" software (non free), as well as with the free (as in free beer) HDSDR software.

The "Ext I/O" connector is used to control extensions of the FDM-S1. This socket offers for example a "Mute" input, used to mute the receiver when transmitting with another radio. Further the ExtIO offers frequency information and various switching signals, to used for example for antenna selection, band filters etc. With these functions the FDM-S1 offers many possibilities for own experiments, unlike other SDRs.

Included in shipment of the FDM-S1 is a USB cable, an adaptor SMA/BNC plus a CD-ROM with the english language manuals (PDF). Size 108 x 27 x 88mm, weight 180g.

As most software the programs for the Elad FDM-S1 are continously developed and extended. For example the manufacturer plans a server component, which will allow remote operations. This server will reduce the required bandwidth, so that slow data lines can be used for remote access. Unfortunately it is not known at the moment, if this software extension will be available for free or as a payable option.

Order No.
FDM-S1 Elad FDM-S1 SDR Receiver incl. Software FDM-SW1 369.00 € Buy now
Test from "Funkamateur" 9/2012 (German, PDF, ca. 3MB)
Test from REFLEXION Nr. 255 1/2014 (by friendly permission of UKW/TV-Arbeitskreis e.V.) (German, PDF, ca. 0,27MB)

New FDM-S2 SDR Receiver (Software Defined Radio) with DRM function


The SDR receiver FDM-S2 is similar in many areas to the FDM-1: the casing of the FDM-S2 is a bit bigger, the interfaces and connectors are nearly identical, the same SFE experimenter boards (see below) can be used.

The most important difference between FDM-S1 and FDM-S2 is the AD converter and the directly covered frequency range. Because the AD converter of the FDM-S2 is of a newer generation, it is more efficient: it scans faster and with higher resolution. Consequently the direct (without 'undersampling') covered reception range is increased, with the FDM-S2 up to 52 MHz (FDM-S1: 30 MHz). Additionally the new AD converter has a word length of 16 Bit, which allows for a finer resolution and an improved dynamic range. Another consequence of the new AD converter is the improved receiver in the VHF range (with undersampling). This way the FDM-S2 receives WFM without problems and the RDS signal is decoded as well. For better VHF support the FDM-S2 has its own, second antenna input (SMA connector). Please notice: VHF range is not available continuously, but only from 74 to 108 MHz and from 135 to 160 MHz.

Another improvement of the more efficient hardware is utilised by the included FDM-Sw2 software: It can now decode up to 4 'virtual' receivers in the same passband. Adjust every receiver independently to operating mode, filter, volume, squelch and so on.

Differences FDM-S1 / FDM-S2
FDM-S1 FDM-S2
Sampling rate ADC 61.44 MHz 122.88 MHz
Word length ADC 14 Bit 16 Bit
Direct Sampling Range 20 kHZ — 30 MHz 9 kHz — 52 MHz
Undersampling Range up to 170 MHz up to 160 MHz
Size 108 × 88 × 27 mm 110 × 90 × 40 mm
Weight 180 g 360 g
Price 369.00 € 525.00 €
Order No.
FDM-S2 Elad FDM-S2 SDR Receiver incl. software FDM-SW2 525.00 € Buy now New

SFE Experimenter Boards FDM-S1/FDM-S2

For your own experiments, two partially populated boards are available for the FDM-S1 and FDM-S2. This allows to build own extensions like a pre-selector, antenna switch, transmit/receive switch, pre amplifiers and much more.

The boards are partially assembled, and come either with or without relays. On the board the I2C bus of the SDR is available for frequency control, further 7 individual switching signals can be used. The state of each of these 7 signals is shown with a LED for easier debugging. The breadboard space is available for own electronics. The board offers the required supply voltage as well.

Order No.
FDM-S1-SFE-R SFE Board with relays 46.50 € Buy now
FDM-S1-SFE SFE Board without relays 24.50 € Buy now
FDM-S1-BOX Empty box for board 20.00 € Buy now

Elad SDR FDM-S1 FDM-S2 software defined receiver hf shortwave usb DRM