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Reviews For: RFSPACE SDR-IQ Software Defined Receiver and Spectrum Analyzer

Category: Receivers: General Coverage

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Review Summary For : RFSPACE SDR-IQ Software Defined Receiver and Spectrum Analyzer
Reviews: 30MSRP: $399
The SDR-IQ™ Software Defined Receiver and
Panoramic Adapter

Product is in production
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# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
AD4C2006 Rating: 2015-01-23
GREAT RECEIVER Time Owned: 0 to 3 months.
I played with a Flex-5000 three years ago and knew how good SDR radios are.
I own a wonderful K3 for few years and the P3 panadapter that worked fine but it lacks features like for example been able to hear audio of the PC.
Recently purchased this SDR-IQ little black box and attached to my PC and took the sample of IF from the K3 (8.215 Mhz) BNC connector at the rear.
My first impression was WOW! this panadapter works definitvely better than the P3 and now I can hear the received audio also at the PC.
Comparing the SDR-IQ as receiver with my K3 which for me has been the benchmark for radios comparison in all these years I own it I can tell that:
1- The noise floor on this SDR-IQ is few db lower than my K3
2- The selectivity although is not so good as my K3 is pretty good for SSB and CW work. Filters are sharp.
3- NB although is not so efective like in my K3, still works ok wiping out all the power lines noise and likewise the K3, it won't add distorsion at the received audio.
4- Ease of set and use, the K3 is kinda complex to set and use, in this little receiver settings takes few minutes and operate it is very simple.
5- Its as sensitive as my K3, no difference between them.
6- It has no notch cancelling as my K3 but for me it won't be needed because I will use it only as a panadapter and eventually as a traveller radio receiver.
7- The received audio trough the PC using this SDR-IQ is very clean although lacks "low end" freqs as at my K3 that has plenty of lows.
8- The panadapter speed of this receiver is faster than the P3 I owned.
9- The IF input amp has more gain than the one at the P3 so I can make the received signals as tall as I want on the monitor screen, in fact I don't even need amplification at all, I set the IF gain at zero db.
For any reason I don't know, the side bands are inverted, so when I hear a station on 40M on LSB, when I tune it on the SDR-IQ to be able to hear it again trough the PC, I will have to set it up on USB, wierd behavior but not a biggy anyway.
I am using as software the Spectravue that came within the installation CD and although is very simple to set and use, I probably will try a more complex software.
So far after few days using this small receiver, I am very pleased with its performance.

2E1RDX Rating: 2014-07-06
Fantastic Time Owned: N.A.
I have the SDR-IQ running with my FT-2000 via a IF-2000 interface This is my 4th SDR-IQ I just keep coming backto them
It's a fantastic receiver very quite once set up correctly ?? for all those that complain they are too noisy When using Spectravue software. On the main screen bottom right below the mode buttons click set up then tick the AGC on and adjust AGC Knee to between -70 and -80 and you will have a stunning receiver with very quite noise floor.
I also see complaints about Spectravue software being basic ?? What it's the most stunning Panadapter out there my basic settings again tranform it for click and shoot with your mouse bottom left of main screen FFT ave to 21 FFT/BLK 4096 you need to have the receiver in the off position to set FFT/BLK otherwise it is just greyed out then I set V scale to 5db/Div you now have a very steady but sensitive Panadapter and very quite receiver that is more than a match for 90% of transceivers with a good set of computer speakers it will surpass received audio on most transceivers. I just love the simplicity of Spectravue and SDR-IQ I use it very well with HDSDR as well with full tracking stunning
rgds ian
N2DTS Rating: 2013-09-18
great for the money Time Owned: more than 12 months.
Ok, I have had a flex 3000 and 5000, a qs1r and the sdr-iq.
For what I do with the radios, the sdr-iq has been the best.
Not the best raw performance, it is not bad, just not the best. Its the ease of use I like, and the fact that there are three stable well working programs that run with the sdr-iq.
Spectraview (used as a lab tool mostly), sdr-console (my favorite) and hdsdr, very nice also.
I have never had a problem with any of these programs, and they never do anything odd.
You can also use all three of those programs without using a keyboard, you can do everything with the mouse. Not having to use a keyboard clears the operating desk.
My qs1r works a bit better, but the software does not seem to be stable or ham friendly.
PowerSDR is quite good, but the radios are expensive.
The major difference I can tell between the sdr-iq and the qs1r and the flex 5000 is a slight bit more background noise on the sdr-iq.
My sdr-iq does not overload on my 80 and 40 meter dipoles, while the qs1r needs a preamp on the higher bands, the sdr-iq has one built in.

Like Powersdr, sdr-console has all the buttons on the screen, band and filter buttons, display options, you can add buttons to the screen or hide them. It remembers where you were on each band, even after you restart, something the sdrmax program on the qs1r does not.
There are a lot of things that bug me about the sdrmaxV program, plus the frequency is off and is not stable, while the sdr-iq is spot on, always has been, and I never needed to correct it.

I think sdr# (sdr sharp) also runs on the sdr-iq, so that is FOUR programs you get to choose from, you are not stuck with a program with bugs or one you do not like.

So, all things being considered, I like the sdr-iq as a receiver and band scope for ham operation, because its runs with various sdr programs.
And revisions in the programs have reduced the background noise level. HDSDR has some very good fidelity.

It would be nice if they made an sdr-iq with a 16 bit converter for more dynamic range and less noise, but I do not have a problem as it is.

Earlier 5-star review posted by N2DTS on 2012-01-18

Been using the sdr-iq as a standalong receiver with the homebrew AM transmitters after building a small box with micro relays in it to mute the audio out from the computer and short the antenna to ground. Works great! I get to see my signal going out, and could even record it for later playback. With the HDSDR and sdr-radio programs, there is much to like, the displays are fantastic, the audio is fantastic, the 190 KHz display is fantastic, it really blows away the flex 3000 on receive.
I keep switching between hdsdr, sdr-radio and the flex, and sdr-radio is the BEST, but hdsdr has a really great display and some nice options.
I am no longer fond of the psdr software and the flex 3000, never use it, and might sell it off.
The only reason to keep it is for a backup rig since it does have a transmitter in it.

The sdr-iq is a very good value, its really 3 great radios and a nice piece of test gear, great for a remote receiver over the web, great as a recorder, not audio, but up to 190 KHz of rf bandwidth can be recorded.
Its little, rugged, powered by the USB port, what more can you ask for?!
Software will only get better I suppose, but its hard to think of any way to improve it.
Running the radio localy with a big monitor is stunning, the over the web use is a bit compressed, so if you try that, keep in mind a local sdr-iq is even much better looking when local.

Also, the sdr-iq likes a good antenna, many of the receivers on the web seem to have very poor antenna's.
On my dipoles, I get very low noise and great performance.
At my noisy work location, with a 50 foot low long wire antenna, it works but is still subject to the poor antenna.
I also found out the power supply for the work laptop was generating HUGE amounts of noise.

For what I do, the sdr-iq and the new software is the BEST receiver I have ever had, better then a flex 5000, better then anything out there at any price.

Earlier 5-star review posted by N2DTS on 2012-01-06

I had one a few years ago and sold it to get a flex, but missed the little IQ and got another one when I tested the new sdr-radio software by using remote radios on the web.
That software is VERY good, much nicer then spectravue, which makes a good spectrum analyzer out of the sdr-iq.
The sdr radio software has very good audio, all the right buttons, and makes spotting signals easy.
The sdr-iq seems to work as well as my flex 3000 as a receiver, and with the sdr-radio software, has even more features then the flex psdr software, a good sync detector, ecss detector, the ability to select the sideband in the ecss detector mode, a noise blanker that really works and other nice features.
hdsdr also works, so its sort of like having 3 radios and a piece of test equipment, and I suppose all the software will be improved even more over time, or new programs will arrive.

As I type this, I am listening to 80 meters with the receiver, on the same laptop, in the den, and it sounds great.

All the free software installed on my computers without any problems and does not seem to use much processor power.
I am going to make up a t/r switch box to allow use of the sdr-iq as a receiver with the transmitters, the sdr-iq needs to be protected from high level rf and muted, a micro relay to ground the receiver antenna input and open the audio from the computer, right at the sdr-iq in a small box, and that should allow me to see my signal as it goes out the antenna which should be interesting.

The radio stays the same (good) and the software seems to get better and better, for free!

Earlier 5-star review posted by N2DTS on 2008-11-15

Today, I hooked the lap top sound card output (headphone jack) into the marantz audio amp I use with all the shack receivers, this feeds into a 3 way speaker (12 inch woofer) and the transmitter mixer.
I did a switch between the homebrew single conversion (tube ) receiver and the icom 756 pro 3, and sdr-iq.
I was operating on 80 meters AM, and made a recording using all 3 receivers, then played back over the air.
The sdr-iq sounded very nice indeed, the adjustable filters help bring out the high end.

I also tuned in ssb signals and cw signals, and everything sounded very good.
The homebrew receiver might have a slight edge in noise and fidelity, but that is what it was designed for.

I think, as a receiver, the sdr-iq is very good.
Its hard to fine tune ssb, but otherwise its very god in my book.

Earlier 5-star review posted by N2DTS on 2008-11-14

I hate computers...I use them all day, and software is a mess.
But this radio works very well indeed, I just spent 4 hours checking out everything from just above 500 hz to 30 MHz, the CB band comes in real well!
It seems to work well on AM, SSB and CW, the display is great, easy to spot even weak signals, click on them, and listen to them.
Weak signals show up on the display before you can actualy copy them except CW which you can hear if you can see it.
The filters work very well, the noise blanker seems to make things worse.
I had no problem getting the IQ working on my laptop and desk top, both are low end units by todays standards. As others have pointed out, there is no book or manual, no info on what things do. tip: you have to push the start button before the receiver works.
But its easy to figure out how to use by poking buttons (once you turn it on).
Tuning is somewhat odd, you get a maximum of 190KHz on the display, you can click the demod button and if you point the mouse to a signal and click on it, that is what you hear, but you have to fine tune it another way on cw and ssb, by selecting the frequency numbers and using the up and down keyboard arrows.
If you click the demod freq button again, it changes to center frequency, then, if you click on a signal, that becomes the center frequency of the display....
You can click on any number on the freq display and up and down arrow. Unlike a real radio, there are no band buttons, its sort of like an old R390a, turn the MHz knob from 160 to 10 meters.......

Still, if you center the display in a band of interest, you can just click on any signal with the mouse and listen to it.

The receiver seems to work as well as any other receiver I have had, with maybe a bit more background noise.
Fidelity seems good, but sound card limited maybe, most computer stuff is not HiFi...
My Sony laptop does not have enough volume, even in the headphones.
I could NOT get winrad to run on XP (desktop) or Vista (laptop), no matter what I tried.
There are other programs out there I would like to try, the persius software looks real nice but wont work unless it detects a persius radio.
Spectravue works at least.

I would like to see a drag and drop filter adjustment, you have to click on a box and open it up, use up and down arrows to adjust the filter, then close the box the way it is now.
Gain adjustments are the same way.
I did not have any overload problems using a G5RV antenna with no tuner (up about 40 feet).
I did hear all sorts of VLF stations, 160, 80, 40 and 20 meters had a lot of signals on them, lots of CBers heard, short wave broadcast was good, as was the AM broadcast band.
It was very interesting watching the CB band, see something on the waterfall display and click on it and listen, hop all over the band, as most CB transmissions are short, see the ones with signals 10 channels wide!
This is going to be great for when 10 meters is open.
For $500.00, its a good receiver.
Its quite amazing otherwise, its very small, needs no power, just an antenna connection.
Maybe the software will improve over time...


KE5JPP Rating: 2012-10-14
Not very good Time Owned: more than 12 months.
I have compared the SDR-IQ to a lot of other conventional and SDR receivers and its performance is lacking. A previous reviewer stated that the SR-IQ is on par with his TS-590s. I own a TS-590s also, and I can tell you that the SDR-IQ is no where in the same class as the TS-590's receiver!

Having very little front end filtering, and insufficient dynamic range, the SDR-IQ overloads easily on strong signals. I found that I had to add an external pre-selector and preamp to get adequate performance. Unfortunately, when you add up the cost of the SDR-IQ along with the other parts needed to get adequate receiver performance, you might as well have purchased one of the more expensive, better performing SDR receivers on the market.

I do not like the manufacturer's software called SpectraVue that comes with the SDR-IQ. It is very basic. I tried to like SDR-RADIO, which is a software partner of RF Space, but it has too many unresolved bugs. I use HDSDR with the SDR-IQ, which is not written by anyone associated with RF Space. Basically, there is no excellent software package to pair with the SDR-IQ at this point.

WV4I Rating: 2012-10-13
great with SDR-RADIO Time Owned: 0 to 3 months.
I'm fairly new to SDR so will keep this basic. I have an RFSpace SDR-IQ that I run with SDR-RADIO software. Works great. I also tried Spectravue, but the functions of that application are not nearly as intuitive, don't have it figured out yet. I run Win 7 on a PC with several other USB devices besides SDR-IQ. SDR-RADIO site is one stop for drivers, and program.

I think this receiver is on par easily with my TS-590S. With an external T/R switch, the SDR-IQ can be used for receive and TS-590S for transmit, being mindful of T/R changeover times, and potential damage to SDR-IQ unit. I plan to do this with a Tohtsu CX-600M relay that has a max switch time of 20ms vs can set TS-590S to 25ms.

The SDR-IQ has a max 190kc range at a time, so particularly nice for looking at pileups, barely open bands, and yes you can hear and see both good and bad audio on SSB.

While it cautions direct hookup to antenna and potential ESD, etc., these std precautions apply to all receivers.

I note the SDR-IQ utilizes your PC's sound card via USB (for both I/Q sigs and sound, and not via stereo input line separately for the sound). I have another very basic SDR that uses the stereo in line for I/Q, and USB for control, that I am yet to get working properly, appears model sound card really matters in such an application, but not with SDR-IQ.

For what it does, can do, the SDR-IQ is a great value, especially for those that listen far more than talk.
WA3DQS Rating: 2012-05-15
Very good as Panadapter Time Owned: 6 to 12 months.
This receiver can be used with Yaesu FT-2000 or FT-950 transceivers - the IF-2000 module installs easily into those transceivers, and the combined price of the IF-2000 and SDR-IQ is less the cost of a DMU-2000 (which requires a dedicated keyboard and monitor.) The SpectraVue software has all the features you'll need for a panadapter - just lock the SDR-IQ receiver on the 10.5 MHz IF frequency. SDR Radio software may have some advantages for general coverage operation with a dedicated antenna, but SpectraVue is a nice stable program that's not hard to adjust. I can switch between HRD (which is running the FT-950) and SpectraVue on the same PC, and the panadapter really makes it easier to adjust both RX and TX menu settings. With a laptop, SDR-IQ, and a simple antenna, you've also an easy SWL setup with dual receivers.
KF7DS Rating: 2012-04-26
Great RCVR Time Owned: 3 to 6 months.
I think the previous reviewer missed the point in blaming poor performance of the SDR-IQ on the failures of SDR-Radio the "program". I agree, SDR-Radio is beta/work in progress - I have seen it run on a friend's computer and it crashes a lot, but it will not run on mine. And, Simon Brown, the author, says this is due to driver problems, even though that same driver will work with my SDR-IQ and Spectravue, Winrad, SDRdx, etc..

The RCVR is very sensitive and can pick out signals that my IC 7600 just misses. In this regard, the SDR-IQ RCVR seems to perform as well as the QS1R, but is inferior to the QS1R in terms of closeby strong signal rejection. I run my SDR-IQ as a dedicated RCVR running Winrad...Winrad is great, easy interface, and just works. Everything is tied together with DXLab Suite and Virtual Serial Ports.

I would give the radio a 5 but nothing is perfect.

TTOMAS59 Rating: 2012-04-19
so so choice Time Owned: more than 12 months.
The SDR-IQ is a good basic general coverage receiver the positives of which have been stated in other posts. On the negative side it suffers from poor dynamic range(making listening to ham signals less than optimal), poor sensitivity above 10 Mhz, and poor implementation when used with SDR Radio software. These issues will become more obvious to new users after the initial fascination of using SDR-IQ wears off.

SDR Radio can be best described as Rube Goldberg like. It has multiple features many of which don't work properly. As a result using SDR-IQ becomes an exercise in frustration for many users. Problems with remote access render it useful only about 60% of the time in my experience. There are interrupts, screen freezes and the need to reboot often. Users all congregate to the Yahoo group where they find few answers. Best thing that could happen is SDR Radio go the route of HRD and allow other developers to fix it. This is poor software as is. If it had to do it over I would purchase the QS1R or the Perseus which I plan to do soon.
W4RCY Rating: 2012-03-26
It is the most incrediable receiver that I have owned. Time Owned: 0 to 3 months.
I have owned this receiver for a couple of weeks. In performance it exceeds any rig I have ever owned. I am currently using it as my primary receiver, and my TS-590s as the the transmitter. Software is constantly evolving. This $500 receiver
gives $7000 performance.
KDMSKY59 Rating: 2012-03-18
re review Time Owned: 6 to 12 months.
This is a re review of my post from a few months ago. The functionality of the SDR-IQ radio has been harmed by the RF Space's decision to align with the makers of SDR-Radio. SDR-Radio software is in a continuously evolving state where new versions and betas of the software are being issued before previous issues have been fixed.

Problems include using remote access, adapting SDR-IQ has a panadapter for transceivers, IQ data file recording, and others. The SDR-Radio Yahoo group attests to countless unfixed issues. Ironically everyone seems to heap praise on the software probably because it's free and you don't want to offend someone who may have the solution to your issues. In addition the control operators at the server have acted vindictively against users who do criticize the software.

For instance when using remote access I've been blocked from accessing my own server when I limited access to others who were accessing my radio excessively and listening to one frequency for hours at a time.

Another problem with the RF Space/ SDR Radio alignment is it may prevent new features from being added to HDSDR and Spectravue. HDSDR is a superb which I would use always if it provided remote access.

Otherwise the SDR-IQ is a great SDR for general purpose listening but not dx.

Earlier 4-star review posted by KDMSKY59 on 2012-01-23

This is a re review of my original review of the SDR-IQ. After six months use and comparing it to the Perseus, the radios shortcomings have become evident. The radio needs external audio filtering due to white noise internally generated within the receiver. As such it is fine for general coverage listening but is far from a dx machine especially on medium wave.

Another particular issue is the SDR Radio software. It is made by the makers of HRD so the nice features it provides are offset by the number of technical issues that arise. Features such as remote access and using the radio as a panadapter become needlessly complicated as evident by the number of technical posts on the SDR-Radio Yahoo group. My wish is that the makers of SDR Radio would iron out problems in current versions instead of adding new features so fast.

My favorite software by far is the HDSDR without which I would sell the SDR-IQ and use the Perseus only. The Perseus software has a top notch noise blanker, and Perseus itself is far quieter eliminating the need for outboard filters. Also the Perseus can be used with HDSDR for those who have issues with the GUI screen size.

My rating is now a 3.5 out of 5 for the SDR-IQ.