SDR-IQ and SpectraVue with a ICOM IC-R7000

[JohnBreen]

Hello,

The title says it all. I am addicted to my Yaesu FT-950 using a SDR-IQ and SpectraVue. Having recently been gifted several Icom receivers I would like to set up my "new" ICOM IC-R7000 with another SDR-IQ and SpectraVue. Understanding that I will be limited to 0.19 MHz of band width (any way to go wider?), I still think this could be great fun. But how is it done?

I am confused about the SDR-IQ's upper frequency limit of 30 MHz and how it could be used with a VHF / UHF receiver but from reading in this forum it seems that it is being done. What cables need to be used to connect the SDR-IQ and the computer and the IC-7000 - and who sells them? Any suggestions for setting up the SpectraVue settings?

Any/all help will be greatly appreciated.

Regards, John (N3JPB)

 

[KC1UA]

The 10.7 IF output of your R7000 should be connected by coax to the antenna input of your SDR-IQ. Tune the SDR-IQ to 10.7 MHz and you should see whatever signals appear within the IQ's passband, which is about 190 KHz maximum. It's not overly effective for VHF and higher signals but it will work. I use the discontinued SDR-14 with an AR5000A+3 to see up to about 10 MHz of spectrum at a time along with full tuning control. If you're just getting your feet wet with spectrum analysis you'll soon be addicted. In my opinion there is no consumer level equivalent to the SDR-14/AR5000 combination. Have fun!

 

[KC1UA]

A few things I neglected to mention in my previous thread:

1. You'll have to use the VFO of the R7000 to tune to any signals you see on the Spectravue display.
2. You may have to tweak your input levels for best performance.
3. The fact that it's not overly effective means that you're not going to see a wide range of signals in 190 KHz of space at VHF or above. But, what you do see displayed should look fantastic.

 

[Token]

A few things I neglected to mention in my previous thread:

1. You'll have to use the VFO of the R7000 to tune to any signals you see on the Spectravue display.
2. You may have to tweak your input levels for best performance.
3. The fact that it's not overly effective means that you're not going to see a wide range of signals in 190 KHz of space at VHF or above. But, what you do see displayed should look fantastic.

Selection of the "Icom IC-R8500/R7x00/R9x00" under the ExtRadio Setup tab will not allow for control of the IC-R7000? I must admit, I have never tried it myself despite having an R7000 here, but I know it works fine with the R8500 and R9000.

To the OP, remember that there is a DC voltage on the IF port of the IC-R7000. The SDR-IQ has a DC blocking cap on the input so this DC voltage should not hurt it, but other devices might not be so lucky (for example when I use my WinRadio Excalibur on the IF of the R7000 or the R8500 I have to use an external DC blocking cap to avoid damage to the Excalibur).

T!

 

[KC1UA]

Hmmm...guess I missed that...maybe the R7000 will work...only one way to find out, get it connected via serial connection to your PC and configure for the correct serial port in SpectraVue. Must be a more recent addition or I'm just completely unobservant (which is entirely possible). I've been using my SDR-14 with the AR5K for so long I haven't looked at that part of the config in a long time.

 

[JohnBreen]

Thank You

Hi guys,

THANK YOU very much for your responses. I have been asking around for a month and this is the first real help I have gotten.

OK, I am going to try all of that. I will try to use USB connections because of the 6 computers in my radio room only one has a serial connection and that one is currently occupied. If I can get this working I will invest in another SRD. Unless I get a suggestion for another SDR as a second receiver - one that can get me enough band width to look at all the air band or all the marine band.

Actually, I have an SDR-IQ connected to my Yaesu FT-950 via the internal RFSPACE board for the FT-950. It is awesome and that is the reason I would like to get something together for VHF / UHF.

Thanks again and best regards, John (N3JPB).

 

[KC1UA]

Once in a while a used SDR-14 will pop up on eBay. Most people that buy them keep them! RFSpace does have newer versions of hardware that should perform similarly, their website which I'd expect you're familiar with to some extent will shed some light on that. I'm not sure what other SDR's will offer such a simultaneous wide view coupled with full computer control of VHF/UHF receivers. My SDR-14/AR5K combo is rock solid and I wouldn't trade it for anything. I've owned a few different spectrum analyzers and the AOR SDU5600 which I hated, as well as an Avcom SDM-42A spectrum display unit. None of them compare to the SDR-14.

 

[JohnBreen]

another thought

One of the things I have noticed is that the IC-R7000 is computer controllable "right out of the box". So, if I get the control cable that connects the IC-R7000 to the computer and use the 10.7 IF from the ICOM to the SDR-IQ (the way it is done with my FT-950) SpectraVue might be able to pull all this together so I can do "point and click" tuning (the way it is done with the FT-950). Well, we shall see.

Thanks again guys.

Regards, John (N3JPB)

 

[JohnBreen]

Maybe picking up a SDR-14 for the IC-R7000 would make a better match - the SDR-14 gives you a 30 MHz pass band width for the spectrum display whereas the SDR-IQ provides a band width of only 0.19 MHz. Regrettably, available SDR-14's on the "used market" are as rare as hen's teeth.......................

 

[Token]

Maybe picking up a SDR-14 for the IC-R7000 would make a better match - the SDR-14 gives you a 30 MHz pass band width for the spectrum display whereas the SDR-IQ provides a band width of only 0.19 MHz. Regrettably, available SDR-14's on the "used market" are as rare as hen's teeth.......................

One of the reasons the SDR-14 has been discontinued is probably because, in many ways, it is no longer competitive. At its price point it is less capable than anything else in the field for most user aplications.

Remember that with the SDR-14 you might be able to display 30 MHz of width, but not if you want to demodulate (from the SDR) a signal at the same time. That means if you just want to look that wide it is fine, but if you want to look and listen you are limited to the same 190 kHz that the SDR-IQ is. The R7000 will always work to demode the signal, that is not a problem, but you get away from the demodulation mode diversity and variable filters of the SDR with that aproach.

Also, you will not get 30 MHz of width out of the IF of the R7000. I do not have the numbers here at work but I bet you are limited to 16 MHz or less of bandwdith on the 10.7 MHz IF.

For almost the same price as a gently used SDR-14 you can get a new WinRadio Excalibur. The Excalibur will show you the full 30, or 50, MHz widths while still allowing you to demodulate signals in the range (however, the R7000 will have the same limited IF band width). Unfortunately the Excalibur software does not allow for control of the R7000 from within the GUI.

For slightly more you can get a Perseus or a RFSpace NetSDR, both allow up to 1.6 MHz of width and the ability to demodulate at the same time. The NetSDR is slightly more expensive, but I believe SpectraVue will control the R7000 directly.

If you only intend to use the SDR behind the R7000, and not as a stand alone receiver, a good possible answer for you might be the QS1R.

The point is, make sure you match up hardware capabilities (systemic, all working together) with your anticipations.Writing down a list of requirements, what you want the hardware to do, might be a good starting point.

T!

 

[woodpecker]

The R7000 will work just fine with an SDR-IQ, 14 or NetSDR. I have all 3 RFSPace models and use them with an R7100, R9000 and R9500, just set the correct CI-V address in Spectravue.

Things are also possible with the excalibur as it supports winradio RBasic, unfortunately the RBasic command set is a bit limited but I wrote a program that controls an AOR SR2000A from within the G31 software. It point and click tunes ok but there are 2 issues, first is the spectrum is inverted and second its not possible to send an offset back to the G31 software to give the correct frequency in the software, it still works great as a click and tune spectrum display though.

 

[JohnBreen]

Hmmmmmmm, lots of good thoughts there. Thanks to both of you for your thoughtful responses.

I better "walk before I run" and try using my SDR-IQ (which I really like) to see what I can actually do with (and without) the R7000 (which I have grown to really like) before I invest in something else. This whole SDR technology is continuing to evolve and develop very quickly. Having only "recently" come back into amateur radio after a lengthy absence I and surprised and delighted by the "stuff" that is now available. Although, I do have first and second generation Winradios (WR-1000 and WR1550) still in service in my radio room (WR discone at the end of he wires).

Thanks again.

JB (N3JPB)

 

[LesWurk]

"
"To the OP, remember that there is a DC voltage on the IF port of the IC-R7000. The SDR-IQ has a DC blocking cap on the input so this DC voltage should not hurt it, but other devices might not be so lucky (for example when I use my WinRadio Excalibur on the IF of the R7000 or the R8500 I have to use an external DC blocking cap to avoid damage to the Excalibur)."



There is a resistor you can clip in the IC R7000 to remove the voltage on the IF out. The voltage is present to power the TV convertor option.

 

[JohnBreen]

Thanks for the heads up LesWurk, I will keep that in mind.

Regards, John(N3JPB)

 

[prcguy]

I have an Icom R7100 which replaced the R7000 and they have the same 10.7MHz IF output. I've connected a spectrum analyzer to the IF out and was very disappointed with the radios AGC affect on the displayed signals where they get cut way down in level as the signals get close to the center tuned frequency and the whole display drops drastically in level as the signals are actually received by the radio.

The amount of signal and noise floor drop on the external analyzer is proportional to the signal strength where stronger signals push all display levels down farther as they are received by the radio.

If the R7000 has the same effect its basically useless to connect a spectrum analyzer or SDR to the IF out.
prcguy