High Quality SDR recommendation

[jcardani]

Hi All,

I would like to purchase a good quality SDR to receive VHF and above. I am in a fairly dense signal environment and my ICOM R7000 and R8500 receivers work well. So I would like the SDR to be not only sensitive and selective but reject any images too. Like strong pager and other VHF/UHF signals.

I was thinking of possibly the USRP (either B200 or USRP1 with daughterboard installed). Or possibly another make such as the new Airspy.

For windows programs it should be able to run SDR# or HD-SDR or others and use virtual audio cable to port the audio to DSDPlus, WinDSD, or Unitrunker.

On the Linux side it would be great to run OP-25
(I have a LiveUSB bootable drive with Ubuntu and GNUradio installed)

Finally instead of using the SDR's daughterboard tuner for VHF etc. would it be better to interface the SDR to the 10.7 IF output of the ICOM receiver? Or even tap to the 455KHz IF and use that. I know the USRP LFRX daughterboard can go down that low. Using the 455 KHz would provide triple conversion already in the receiver.

thanks,
Joe

 

[PACNWDude]

WinRadio could work, but might need some down converter hardware, specific antennas, etc.

I have used WinRadio and the Icom PCR series of black box receivers. Little known fact is that the Government was using Icom PCS-1000's for a short while. Then they converted to WinRadio's.

 

[jcardani]

Hi,

Thanks for the reply!

Does the Winradio interface with GNURadio, OP-25 etc. under Linux? I believe it can work with SDR software and DSD variants using their digital bridge under Windows. But I can't find anything about it working under Linux.

I am looking for a SDR that's going to reject images and intermodulation as well as being sensitive and selective.

 

[jdobbs2001]

I own a B200, I would recommend the Airspy though. the B200 is not well supported in windows.

also for HF/VLF/LF and some of the VHF bands as well I recommend the FDM-S2

 

[jcardani]

I own a B200, I would recommend the Airspy though. the B200 is not well supported in windows.

also for HF/VLF/LF and some of the VHF bands as well I recommend the FDM-S2

Would the ExtIo link on Balint's web site support the B200 in Windows? ExtIO USRP - SpenchWiki

Would the ExtIo DLL allow the B200 (or Airspy) interface with HD-SDR, SDR#, etc. and programs such as DSDPlus (with a virtual audio cable)?

thanks!

 

[Token]

“High quality” and VHF and above are a tough pull, and not cheap. Sensitive, selective, and good image rejection go with high quality. ADC bit depth is a big player in dynamic range and image rejection. So the question is going to be how high is high quality?

Airspy is a nice lower cost option, but dynamic range is not really top of the line. I have not seen good image rejection numbers but suspect they will be fair with the tracking filters. USRP1 probably has less good image rejection, but has the advantage of being more of a research tool with an interesting software selection behind it.

For true high quality SDR covering VHF and up you really have to look at either AOR or WinRadio. The WinRadio G39DDC is probably the best option on the market. Its performance is truly professional level, however for the price it should be. Unfortunately this radio will not work with the software you have specified, the GUI is Windows specific and the hardware has not been well supported by third party developers (despite WinRadio publishing their SDK).

The AOR RF-6G can be used with a 45 MHz SDR to cover any range you want, 500 kHz to 6 GHz. However I do not know anyone in the hobby market who has had access to one.

But you probably have hit on a possible answer, the R8500 and an SDR on the IF. You want to use the 10.7 MHz IF, not the 455 kHz. First the 10.7 MHz IF gives you more potential bandwidth just by virtue of its center frequency. Second, the 10.7 MHz IF is not filtered, while the 455 kHz IF is. This means you get less than 12 kHz of usable BW on 455 kHz, and up to about 18 MHz of usable bandwidth at 10.7 MHz. I have found the R8500’s to be slightly variable form unit to unit, I have seen R8500’s that only yield 14 MHz of fairly flat usable 10.7 MHz IF, and others with more like 18 MHz. Both copies I have here at the house are in the 16 MHz width neighborhood.

While I often use an SDR on the IF of the R8500 I have never tried to do the stuff you apparently want, trunking/scanning/etc with this combination. I have no idea if a software package exist that will interface/control the R8500 and still do what is required with the SDR.

T!

 

[prog]

Airspy is a nice lower cost option, but dynamic range is not really top of the line.

Airspy is a 12bit receiver with 80dB of dynamic range and a matching image rejection. Sure, it's not intended to compete with the "big boys" but it doesn't fall too far ;-) If you get hands on one, I'd like to know your thoughts about it.

Youssef

 

[jcardani]

Airspy is a 12bit receiver with 80dB of dynamic range and a matching image rejection. Sure, it's not intended to compete with the "big boys" but it doesn't fall too far ;-) If you get hands on one, I'd like to know your thoughts about it.

Youssef

Hi Youssef,

Would Airspy work with OP-25 and GNU Radio on the Linux side? Would love to get one but looks like the first preorder is all sold out and would need to wait for the next one.

thanks!

 

[prog]

The GNU Radio is supported since the very beginning so it should be fine. There will be more batches to come. Stay tuned.

 

[jcardani]

“High quality” and VHF and above are a tough pull, and not cheap. Sensitive, selective, and good image rejection go with high quality. ADC bit depth is a big player in dynamic range and image rejection. So the question is going to be how high is high quality?

Airspy is a nice lower cost option, but dynamic range is not really top of the line. I have not seen good image rejection numbers but suspect they will be fair with the tracking filters. USRP1 probably has less good image rejection, but has the advantage of being more of a research tool with an interesting software selection behind it.

For true high quality SDR covering VHF and up you really have to look at either AOR or WinRadio. The WinRadio G39DDC is probably the best option on the market. Its performance is truly professional level, however for the price it should be. Unfortunately this radio will not work with the software you have specified, the GUI is Windows specific and the hardware has not been well supported by third party developers (despite WinRadio publishing their SDK).

The AOR RF-6G can be used with a 45 MHz SDR to cover any range you want, 500 kHz to 6 GHz. However I do not know anyone in the hobby market who has had access to one.

But you probably have hit on a possible answer, the R8500 and an SDR on the IF. You want to use the 10.7 MHz IF, not the 455 kHz. First the 10.7 MHz IF gives you more potential bandwidth just by virtue of its center frequency. Second, the 10.7 MHz IF is not filtered, while the 455 kHz IF is. This means you get less than 12 kHz of usable BW on 455 kHz, and up to about 18 MHz of usable bandwidth at 10.7 MHz. I have found the R8500’s to be slightly variable form unit to unit, I have seen R8500’s that only yield 14 MHz of fairly flat usable 10.7 MHz IF, and others with more like 18 MHz. Both copies I have here at the house are in the 16 MHz width neighborhood.

While I often use an SDR on the IF of the R8500 I have never tried to do the stuff you apparently want, trunking/scanning/etc with this combination. I have no idea if a software package exist that will interface/control the R8500 and still do what is required with the SDR.

T!

Hi Token,

Yes that would probably be the best bet if I use the R8500 or R7000 with USRP. Would need a USRP1 with LFRX daughterboard I believe to tune that low. I think that hamlib coupled with OP25 would be able to change the ICOM freq parameters. Since I would be changing the freq on the ICOM then the USRP would be fixed tuned to 10.7 MHz IF (adjusted for DC offset I think). Again I am not really looking to see a lot of bandwidth.

I still may be able to use the B200 with the ICOM. Another interesting idea would be using the digital voice conversion method I did years ago here.

See: Digital Voice Conversion Method - The RadioReference Wiki

I used the 10.7 MHz output of the R8500, a minicircuits mixer, and rf generator to up convert to a constant UHF frequency. This was originally done so I can monitor APCO 25 voice tuning the ICOM and listening on a UHF Astro saber programmed conventionally to the mixed output freq. This was before digital scanners came out.

So I should be able to tune the USRP B200 to the UHF freq output of the mixer. So anywhere the ICOM tunes the B200 should receive, correct?

What are your thoughts on this?

thanks!

 

[Flatliner]

For Windows use, for VHF to 3.5GHz, the Winradio G39 will work well. The HF performance isn't as hot, but the G33 fits that end nicely.

For Linux, the new Ettus USRP E310 looks really good. 70MHz-6GHz, 56MHz bandwidth. It should work with Windows under GNUradio too. It's a transceiver also. I'm tempted to also grab one of those myself!

 

[Token]

For Windows use, for VHF to 3.5GHz, the Winradio G39 will work well. The HF performance isn't as hot, but the G33 fits that end nicely.

Odd, I find the G39DDCe quite good on HF. I would say it is as good on HF as the G31DDC, and that is excellent. True, the G33DDC is slightly better, the front end is more robust with its filter network, but realistically it is almost impossible to tell a performance difference between the three except under the most extreme conditions.

Unfortunately the cost of the G39 simply puts it out of the reach of most hobbyist, however it is probably the one radio that will do almost anything you want it to, Longwave to Microwave (and with the converter can go above J band), as long as you can do it with the factory software.

T

 

[Token]

I used the 10.7 MHz output of the R8500, a minicircuits mixer, and rf generator to up convert to a constant UHF frequency. This was originally done so I can monitor APCO 25 voice tuning the ICOM and listening on a UHF Astro saber programmed conventionally to the mixed output freq. This was before digital scanners came out.

So I should be able to tune the USRP B200 to the UHF freq output of the mixer. So anywhere the ICOM tunes the B200 should receive, correct?

What are your thoughts on this?

Sure, that should work if you want to go to the effort or already have the gear in hand. There will be some conversion loss, but you can make that up with an IF amplifier.

There are multiple SDRs that should be able to tune the 10.7 MHz IF though, from $70 Softrocks to any upper end you want. So unless you are sold on the USRP for some reason you should be able to do it without a mixer and LO.

T!

 

[NYG]

Would the ExtIo link on Balint's web site support the B200 in Windows? ExtIO USRP - SpenchWiki

Would the ExtIo DLL allow the B200 (or Airspy) interface with HD-SDR, SDR#, etc. and programs such as DSDPlus (with a virtual audio cable)?

thanks!

The Extio does support the B200. I've used it with the original USRP, USRP2, N210 and B200. SDR-Radio also supports the B200.

 

[prcguy]

I tried using the 10.7 IF out on an Icom R-7100 for spectrum monitor use and was very disappointed with the results. It seems there is heavy AGC action at the IF out and looking at a spectrum analyzer while tuning would show signals off to the side with good dynamic range, then when they got close to the IF filter passband they would get sucked down in level due to AGC. Not sure if the R-7000 or R-8500 works the same.
prcguy

Hi Token,

Yes that would probably be the best bet if I use the R8500 or R7000 with USRP. Would need a USRP1 with LFRX daughterboard I believe to tune that low. I think that hamlib coupled with OP25 would be able to change the ICOM freq parameters. Since I would be changing the freq on the ICOM then the USRP would be fixed tuned to 10.7 MHz IF (adjusted for DC offset I think). Again I am not really looking to see a lot of bandwidth.

I still may be able to use the B200 with the ICOM. Another interesting idea would be using the digital voice conversion method I did years ago here.

See: Digital Voice Conversion Method - The RadioReference Wiki

I used the 10.7 MHz output of the R8500, a minicircuits mixer, and rf generator to up convert to a constant UHF frequency. This was originally done so I can monitor APCO 25 voice tuning the ICOM and listening on a UHF Astro saber programmed conventionally to the mixed output freq. This was before digital scanners came out.

So I should be able to tune the USRP B200 to the UHF freq output of the mixer. So anywhere the ICOM tunes the B200 should receive, correct?

What are your thoughts on this?

thanks!

 

[jet9010121]

I´m starting and I wonder if there are some that can record the espectrum or take a picture….you think these features are important? I mean, some of you bought SDR from professional providers before, and you ve tested the equipment they offer. Which are the features you liked the most about them? maybe

 

[Yagi23]

“High quality” and VHF and above are a tough pull, and not cheap. Sensitive, selective, and good image rejection go with high quality. ADC bit depth is a big player in dynamic range and image rejection. So the question is going to be how high is high quality?

Airspy is a nice lower cost option, but dynamic range is not really top of the line. I have not seen good image rejection numbers but suspect they will be fair with the tracking filters. USRP1 probably has less good image rejection, but has the advantage of being more of a research tool with an interesting software selection behind it.

For true high quality SDR covering VHF and up you really have to look at either AOR or WinRadio. The WinRadio G39DDC is probably the best option on the market. Its performance is truly professional level, however for the price it should be. Unfortunately this radio will not work with the software you have specified, the GUI is Windows specific and the hardware has not been well supported by third party developers (despite WinRadio publishing their SDK).

The AOR RF-6G can be used with a 45 MHz SDR to cover any range you want, 500 kHz to 6 GHz. However I do not know anyone in the hobby market who has had access to one.

But you probably have hit on a possible answer, the R8500 and an SDR on the IF. You want to use the 10.7 MHz IF, not the 455 kHz. First the 10.7 MHz IF gives you more potential bandwidth just by virtue of its center frequency. Second, the 10.7 MHz IF is not filtered, while the 455 kHz IF is. This means you get less than 12 kHz of usable BW on 455 kHz, and up to about 18 MHz of usable bandwidth at 10.7 MHz. I have found the R8500’s to be slightly variable form unit to unit, I have seen R8500’s that only yield 14 MHz of fairly flat usable 10.7 MHz IF, and others with more like 18 MHz. Both copies I have here at the house are in the 16 MHz width neighborhood.

While I often use an SDR on the IF of the R8500 I have never tried to do the stuff you apparently want, trunking/scanning/etc with this combination. I have no idea if a software package exist that will interface/control the R8500 and still do what is required with the SDR.

T!

Image rejection for the Airspy is likely to be around 65 dB given the tuner that it uses. This is pretty reasonable for a Low IF tuner. Unfortunately, the tracking filter will not help much as the IF only a few MHz.

 

[nathkrul]

I own a B200, I would recommend the Airspy though. the B200 is not well supported in windows.

also for HF/VLF/LF and some of the VHF bands as well I recommend the FDM-S2

Just curious why you say the B200 isnt supported well in windows, mine works fine using HSDR and SDRSHARP in windows 7 and 8.1

Tho I might also get the Airspy as well, just dont fancy pre-ordering it..

 

[Voyager]

Tho I might also get the Airspy as well, just dont fancy pre-ordering it..

They are shipping now and for the next 2-3 days. It's the perfect time to jump on one before the second batch stock runs out.

 

[mtindor]

I love my Airspy. I've never had the opportunity to try out a $500+ solution. I have used RTL dongles and Funcube / Funcube Pro Plus for a long time now though. And the difference between any of those and the Airspy is night and day if ya ask me.

RTL dongles just don't have the performance -- the only thing they have going for them are the available bandwidth.

Funcube Dongles do not provide more than 192 khz of bandwidth, and that's their downfall. Otherwise, they perform quite well in a strong signal environment compared to the RTL dongles.

The Airspy gives you 8+ Mhz of usable bandwidth, and if you follow recommended practices for achieving best performance [at the expense of some bandwidth], it handles strong signals close to the weak ones I monitor much much better than anything else I've used.

On my RTL dongles and Funcubes, I can tune 12.5 khz away from a very strong local signal in an attempt to decode a weak signal, and the strong signal either partially or completely encroaches upon the weak signal and makes the copy impossible. WIth the Airspy, running at 10 MSPS and using a reasonable decimation value, I can copy the weak signal 12.5 khz away from the strong signal and the Airspy doesn't bat an eye. The strong signal stays within its skirts and leaves the weak alone.

Notice I didn't use proper nomenclature for some of the things, because I get confused by them all -- I just know I'm extremely happy with my Airspy, especially for the price.

One caveat -- I suspect some work needs to be done on the drivers or something, because in both Windows and LInux I can manipulate various gain/decimation/sample rate values quickly and cause the Airspy to become nonresponsive, forcing me to unplug it from the USB port and plug it back in to get it to work again.

Mike