Review of the FDM-S2 SDR receiver.

[jdobbs2001]

Part I.
I took the plunge and decided to buy and SDR for shortwave listening. I have been skeptical of SDR for such use since I am accustomed to HF = big box with knobs and lots of components inside. I was also skeptical due to (Computer = RF noise not good for HF) The early products did not seem as polished or as “Consumer friendly” as I wanted

Over the last few years I kept an eye on developments, I initially though of buying the Q1SR but decided not to (900 dollar price, concerns about software quality and support) and skeptical about SDR back a few years ago. I looked at other receivers as well Perseus and SDR-IQ

I also looked at the Yaseu/ICOM/Kenwood amateur products with their kilobuck price ranges hoping DSP might help. Over the years I kept an eye on developments.

I have been out of HF listening for about 18 years, RFI noise and difficulty in receiving stuff due to increasing noise floors which really made it hard to discern signals and would bring on listening fatigue quickly. I left my drake R8B in a box untouched for years.

I finally decided to take the plunge and order an FDM-S2 (they were selling for 525USD) I never heard of Elad and they seemed to come out of left field. They seem to be serious in terms of writing software, and the hardware looked polished and what I would call Turnkey radios.

I ordered from ELAD USA the FDM-S2 and in 3 days I got it.

Specs and pictures of the board etc.

ELAD FDM-S2 SDR Receiver

It came in a small box inside a bigger packing box. Inside was 2 USB cables and 1 USB larger cable. a small 8GB flash drive with the software,etc (nice touch for those who might not have a cd drive) a small protective bag if you want to take it with you and two BNC/SMA adapters and 4 stick on rubber feet.

The receiver is tiny and looks more like a polished Apple product than the early SDR stuff I have seen in the past.

The first thing I noticed is how dense it was and the feeling of weight for something small. The machining and silkscreening is done nicely.

I installed the software on my PC, it was a very easy affair, double click on installer and click next a few times. (windows 8.1 was fine, and even windows 7 64bit running as a virtual in a Mac Mini) no issues in either scenario.

A big plus is the fact that it will run off USB power, so connectivity is quite simple, plug antenna in, USB into PC and open the app and your good to go. (I suspect the other USB cables are for older PCs that might not offer enough power from one USB port)


ELAD offers the EXT_IO DLL files and I tested it, all you do is drop the DLL file into the folder of the SDR software that supports it and your good to go.

I quickly tested and confirmed it works with SDR#, HDSDR, SDR-RADIO v2 with no issues.

The FDM-S2 ships with Elad’s homegrown application called FDM-SW2 and so far it is my favorite software for monitoring. It is very very user-friendly and performs exceptionally in terms of noise reduction and overall performance/audio output. It will work in multiple monitors and at arbitrary resolutions. (unlike other vendors which seem to have no interest supporting large/multi monitor setups)

A few things that quickly caught my attention is the low internal noise. The other thing I noticed is how effective the NR is. Turn it on and it practically quiets the receiver, I do not even need squelch for listening to SSB. Voices will just pop out, very clear and very easy to understand.

Its so good I always have the receiver running when working etc in the background and I will always be hearing interesting stuff thanks to the zero listening fatigue and intelligible clear audio.

The quality of the filters are amazing, its like having a perfect brick wall filter, you set it for 2.5khz wide and you get 2.5khz, you can have have a signal right next to it and nothing. I would tune across a crowded SSB band and its pretty amazing to actually witness.

AM quality is very good as well for HF broadcast listening, I will use two of these brick wall filters to create a psuedostereo effect on music stations and it really opens things up. Only way to explain it is you have to listen to it for yourself to really see what I mean.

This receiver is hot and it really picks up signals out of the mud I have not had any issues with overloading or strong signals causing issues.

I posted some videos of it in action for those interested. I will be getting a Tmate2 delivered today as well.

Bottom line if you want HF listening I would recommend this product with no hesitation whatsoever. and it got me back in the saddle now in terms of HF monitoring.


https://www.youtube.com/channel/UCiYxUk6TXbYjp6KTJVHxixg

Part II (more in depth details soon)

 

[SCPD]

Nice review.

All I can say is I fully agree

What made the FDM-S2 even more attractive to me is the coverage of FM Broadcast and VHF.
On FM DX it may be the very best (direct sampling) front end one can get.

The frequency coverage, dynamic range and versatility of the supplied software make this an amazingly priced package.

BTW Elad has been making test equipment for a long time and started pioneering with the first generation SDR/IF receivers. They are also the builders behind smart accessoires like Tmate.

73
Paul
PD0PSB

 

[NYG]

Let us know your thoughts on the Tmate 2 when you get a chance. I ordered one over the weekend to take advantage of the discounted pricing before it ended. It's been difficult to find decent reviews on it though so I've been hesitant to buy it.

It'll replace a Griffin Powermate I've used for a couple of years. The display on the Tmate 2 will allow me to use my SDRs as bedside radios which is a nice bonus for me.

As others may have seem in other threads I completely agree with the quality of the FDM-S2. It's a fantastic radio and the software is terrific.

 

[jdobbs2001]

I have not found any reviews on it yet, it arrives this week. I will definitely put it through its paces and post a review here.

Good to know they are behind the tmate2. I was able to catch quite a bit of VHF low skip yesterday (30-50mhz band) on the FDM-S2 as well.

I just started messing with the dual DDC mode. Thats real cool. Its like having two complete 4 vfo receivers.

 

[shortwaver]

Looks like the FDM-S2 is back in stock.

 

[RZR]

First impressions...

Just got one myself. I too enjoy the FM broadcast band coverage and being able to decode the RDS data. Glad I didn't buy a FM-HD receiver yet, as it is now easy to see that only one station in my area is broadcasting that. Seems to do a fine job on HF also, and is relatively happy using a compromised antenna. I can switch in a few different antennas and it seems to still have decent audio/reception at much reduced signal levels.

Ive not tried the dual mode, as 4 receivers is about too much for me to make sense with, unless your monitoring empty channels to snag a transmission when it becomes active. So I usually do 1 or 2, with 2 being that one is Left channel audio, the other is Right.

I like to do some NDB's as well. This is my first radio with spectrum display so it was a nice surprise to actually see the Morse code dit's and dah's going up the waterfall from multiple NBD's at a time. If fading prevents you from hearing an NDB at present you may be able to snag it visually as a stronger segment is shown in the waterfall.

Not a receiver that I relax much with lol. So many signals and so many receivers I'm almost like a mad dog in a meat house, not knowing what to click on next.

Ive been able to decode text only, one DRM signal so far. Not heard any audio with that yet.

Unit looks and feels solid. Has 2 SMA connectors with adapters to make them BNC. Very easy install, I'm running win 8.1 on a 3.4 Ghz I-3 with 8 gigs rams and 2 monitors. Running full screen on the wide monitor and with 4 receivers going on different modes, it only ran my CPU 8-10%. Sometimes a bit more, but not a CPU hog. Looks impressive lol. Runs very smoothly. I am running an entry level gamer video card with 4 gigs video ram.

No real nags yet, and I've yet to read the manual. I'll have time soon, then I'm sure I'll get a lot more out of it. Nice rig so far, glad you guys were talking about it and made me aware of it.

Rzr

 

[jdobbs2001]

The dual mode is real cool because you can use one channel for NAVTEX nd have it decoding while using the other channel for monitoring other frequencies etc.. I am doing that right now. channel 2 is doing NAVTEX and I am tuning around on channel one
I think the FDM-S2 is the only SDR that offers dual channels, I know the Q1SR was hyped to offer that feature but I don't think it was delivered.

but the funny thing is both channels support 4 vfos with independent outputs to different devices, so if you were doing some kind of special monitoring, you can send all 8 outputs to 8 different recording devices etc..

Another interesting thing, even though it is not advertised. you can tune into the Air band 108-137mhz and listen in. Its also good for 30-50mhz for chasing VHF-lo skip. I caught a bunch of stuff that popped up in that area.

It is a pretty hot receiver, a 102-108 inch whip will get you plenty of stuff to listen. Also they are out of stock again it seems.

 

[krokus]

The 525 Euro price seems a bit high.

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[SCPD]

The 525 Euro price seems a bit high.

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Compared to?

-A RTL SDR?

-A high dynamic range HF SDR with 6MHz DDC + Top spec Direct Sampling FM Broadcast DX receiver + VHF converter & LNA + One of the most advanced SDR software? All in one streamlined package?

Nah... ;-)

73
Paul
PD0PSB

 

[jdobbs2001]

Compared to?

-A RTL SDR?

-A high dynamic range HF SDR with 6MHz DDC + Top spec Direct Sampling FM Broadcast DX receiver + VHF converter & LNA + One of the most advanced SDR software? All in one streamlined package?

Nah... ;-)

73
Paul
PD0PSB

Im curious to know what he is comparing it to. The old 14bit Perseus still sells for 825 euro and if you want FM thats an extra 299euros on top.

 

[NYG]

The 525 Euro price seems a bit high.

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If in the US you don't need to buy in Euro. Go to shop.elad-usa.com and get it for $580

 

[k4pkm]

This is what I have been looking for - price is incredible with the coverage and the great software. Very intuitive if you have been using SDR software before such as with a dongle.
Great ears so far, and the ability to record such a large swathe of bandwidth is also amazing at this price. So far very impressed!
Folks have been very good to deal with here in the USA - very responsive to emails and even alerted me when the units were back in stock, as I had asked when they might be getting more in.
From the Elad Yahoo group discussions it is easy to see they are responsive to users - also impressive.
Just first impressions, but so far very, very happy.

73,
Robert AK3Q

 

[ShiftyPotts]

I am also a happy customer! I only have a few days with the Elad and a week or two with a dongle, and just a few hours with Perseus (over the net).

I especially like the Elad tuning scheme. Very good and intuitive in my limited experience. I had high hopes for this receiver and so far my expectations have been exceeded. I am also encouraged that the software seems to be routinely upgraded. I am also happy with the Tmate2 tuning control. I can change modes by just touching a button on the Tmate, tune, change steps, change BW, change volume, and some other stuff I can't remember. Besides, it looks kinda cool just sitting there.

Bob

 

[jdobbs2001]

I am also a happy customer! I only have a few days with the Elad and a week or two with a dongle, and just a few hours with Perseus (over the net).

I especially like the Elad tuning scheme. Very good and intuitive in my limited experience. I had high hopes for this receiver and so far my expectations have been exceeded. I am also encouraged that the software seems to be routinely upgraded. I am also happy with the Tmate2 tuning control. I can change modes by just touching a button on the Tmate, tune, change steps, change BW, change volume, and some other stuff I can't remember. Besides, it looks kinda cool just sitting there.

Bob

The fdm-s2 is also a better reciever. The perseus is older technology, I am surprise they have not produced a new model.

 

[Thunderknight]

I own an SDR-IQ now...would it be worth buying the Elad for HF?
I know it's 14 vs 16 bit, is that a large enough difference to be noticible? I know the bandwidth is much larger on the Elad, but not sure I really need that capability. I'm more worried about noise elimination and weak signal capability.

 

[jdobbs2001]

I own an SDR-IQ now...would it be worth buying the Elad for HF?
I know it's 14 vs 16 bit, is that a large enough difference to be noticible? I know the bandwidth is much larger on the Elad, but not sure I really need that capability. I'm more worried about noise elimination and weak signal capability.

If your not clipping the ADC of the SDR-IQ then there is no reason to buy the FDM-S2.

The large bandwidth capability is interesting but its kind of overkill, I typically operate at 384k or dual 384k mode (ie dual radio mode)

But for a new purchase I could not recommend the SDR-IQ or Perseus. Since for the price of an SDR-IQ you get a newer more advanced SDR.

 

[k1xd]

Based on your review and several others found on the internet, I placed an order for the ELAD FDM-S2!

It was the FDM-S2 or an Icom R75. I couldn't bring myself to buy the older technology. I'm waiting anxiously with UPS tracking number in hand!

Dave

 

[Token]

The fdm-s2 is also a better reciever. The perseus is older technology, I am surprise they have not produced a new model.

I own the Perseus, I also own the FDM-S2. Other SDRs that are in daily use here are the Winradio G31DDC, G33DDC, RFSpace SDR-IQ, SDR-14, and NetSDR. I also own other less expensive SDRs such as the SoftRock Ensemble II, Soft66LC, RTL Dongles of a couple of flavors, etc. I have used but do not own the WinRadio G39DDC, the AFEDRI SDR, and the QS1R. On the Ham side of things I have the Flex-5000A.

I state the above for one simple reason, so that you understand I don’t really have skin in calling one better than the other, none of my babies are ugly

Besides DDC bandwidth and raw sensitivity, please quantify how the FDM-S2 is a better receiver than the Perseus for the frequency range they share? When did you compare the Perseus and the FDM-S2 in side-by-side testing? What kind of side-by-side testing did you carry out? I am not saying the FDM-S2 is not better, I am just asking what you base your claim on?

To be sure, the Perseus has been around a while. And I consider it slightly over priced in today’s market selection. However that does not mean it performs less well today than it did in the past, and it was considered exceptionally good in the past. I have run the two receivers side by side (had to borrow a Perseus to do so, mine is on the fritz, I actually got the FDM-S2 to replace it), and with the exception of bandwidth and a very slight advantage of the FDM-S2 on a very minimal signal I could not detect any way the S2 was better. In fact, the Perseus seemed to have an advantage when it came to sound quality for SSB and AM signals, and the Perseus software is simpler and more straight forward.

Different tools for different jobs.

For precision measurement I will take the NetSDR with an external reference. The software selection and the hardware allow detection of non-communications signals with greater fidelity and easier integration with analysis tools. The unit can be triggered with an external pulse. With the RFSpace provided upconverter frequency coverage up to above 500 MHz is possible. It does not have the widest DDC bandwidth or the best sensitivity, but the third party software support (including MATLAB stuff) is excellent.

For just all around best receiver use for SWL, UTE, whatever (other than an auxiliary ham receiver application) I will take the WinRadio G33DDC. It is simply one of the best receivers I have ever used, period. The sensitivity is killer. The software does pretty much anything you need it to do (except remote operation), allowing the user very complete control of reception parameters. The wideband display (the entire HF range) is a feature that every SDR should have…but they do not. If I had to get rid of every SDR I currently have except one, the G33DDC is the one I would keep. The G31DDC is a close second. On the down side, the noise blanker for both the 31 and 33 leaves a lot to be desired, that is the biggest operational gripe I have with them.

The FDM-S2 is my new low cost favorite. It is almost as good as the WinRadios are and cost less. The software appears quite capable, although I still prefer the WinRadio GUI. If you are looking for an SDR in the same cost range as an Icom R75 or Alinco DX-R8 then this is the answer, no doubt. If they added a wideband HF display similar to that in the WinRadio GUI I would consider this one a G31DDC killer, although not up to the G33DDC.

T!

 

[ShiftyPotts]

I own the Perseus, I also own the FDM-S2. Other SDRs that are in daily use here are the Winradio G31DDC, G33DDC, RFSpace SDR-IQ, SDR-14, and NetSDR. I also own other less expensive SDRs such as the SoftRock Ensemble II, Soft66LC, RTL Dongles of a couple of flavors, etc. I have used but do not own the WinRadio G39DDC, the AFEDRI SDR, and the QS1R. On the Ham side of things I have the Flex-5000A.

I state the above for one simple reason, so that you understand I don’t really have skin in calling one better than the other, none of my babies are ugly

T!

Token, thanks for the excellent summary. Because I came within a keystroke of buying a Perseus, and because you have much experience with Perseus, can I ask you (and other Perseus users) a question? When I was trying to decide which SDR to start with, I downloaded the Perseus software and spent a few hours hooking into remotes around the world. I thought the GUI was excellent, except for two things: 1) It doesn't seem to go full screen, only about 1/4 my screen. And 2) it seems you scroll "down" to go "up" in frequency. Those two little things were enough to get me to pause and consider the Elad and Winradio.

All of this SDR software is probably quirky. There are a couple of things I might change with the FDM-S2 software, for example, I might put the radio control features across the bottom, instead of the right side. Then there would be room for buttons to change modes instead of pulldown menus. On the other hand, in my Very limited SDR experience, I love the FDM-S2 tuning scheme, double click = center frequency.

I'm just curious if you consider those two Perseus "quirks" to be limitations.

Thanks,

Bob

 

[ShiftyPotts]

Based on your review and several others found on the internet, I placed an order for the ELAD FDM-S2!

It was the FDM-S2 or an Icom R75. I couldn't bring myself to buy the older technology. I'm waiting anxiously with UPS tracking number in hand!

Dave

Dave, I hope you will be very happy with your new toy. I've only had mine a couple of weeks, but I love it to death. And I just have a piece of wire hanging in my apartment window for antenna. I have a new loop and discone to put up, but it's just too hot in my area right now. Maybe in a couple of days. One thing I like about the Elad is the constant effort to improve the software. I think it's been upgraded 3 times in the past couple of weeks. There is a fairly active Yahoo Elad users group, it seems that if you suggest an improvement, a day or two later there is a new version with your improvement! Some users might not like the constant updating, but it doesn't bother me a bit. That's better than software that never gets updated, to me anyway.

Anyway, let us know how it goes for you.

Bob