Remote RSP via USB/CAT5

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glovisol
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Re: Remote RSP via USB/CAT5

Post by glovisol » Thu Aug 30, 2018 4:19 pm

Hi Fresnoboy,

This could be a very valuable idea, but first you must check the QRM locally generated by the small PC board and/or if it can be esily shielded. If this board radiates to the RSP receiver we are back to square one.

glovisol

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OH2BUA
Posts: 83
Joined: Mon Aug 29, 2016 8:58 am

Re: Remote RSP via USB/CAT5

Post by OH2BUA » Fri Aug 31, 2018 12:12 pm

Way to go, Mike.

Seriously, if one does have heavy RFI in location X - according to me, there is no USB, no (antenna) coaxial-based solution even how extended to get RFI-levels acceptably low. The spread is just too narrow.

I recommend everybody not spending xxx eur to proof that personally, like I unfortunately did.

Go at least half a kilometer (0.3 mil) away from any RFI sources. Then it's getting meaningful. And remember: Not _any_ switch-mode appliances at the far end.

73, Jukka

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glovisol
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Location: Piedmont, Italy

Re: Remote RSP via USB/CAT5

Post by glovisol » Fri Aug 31, 2018 3:07 pm

Hi Jukka,
Seriously, if one does have heavy RFI in location X - according to me, there is no USB, no (antenna) coaxial-based solution even how extended to get RFI-levels acceptably low.
Before getting on with this discussion, you should define what you mean by "acceptably low" and also define what type on noise we are talking about. If you carefully read the previous posts in this thread, nobody was referring to a "heavy RFI location X". The point we were and are discussing is ways and means to exploit to the ultimate consequences the unique feature of the RSP receiver. e.g. the HIGH Z balanced input.

If you look at:

https://www.sdrplay.com/community/viewt ... 2&start=30

Photograph: DSC_1114 (Medium).JPG (69.66 KiB) Viewed 559 times

it has been shown already that by directly connecting the leads of a long wire antenna to the balanced Hi Z input of the RSP receiver via a transformer type balun, you definitely obtain a noise advantage in HF reception.

The entire and only purpose of this thread and of its posts is to just find ways to remote the receiver from the PC, at reasonable cost, without creating additional interference, so that the receiver is positioned right at the antenna terminals.

glovisol

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dl1bz
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Joined: Wed Aug 22, 2018 6:08 am

Re: Remote RSP via USB/CAT5

Post by dl1bz » Fri Aug 31, 2018 8:29 pm

The best way my opinion is using the RSP2 over TCP/IP as client-server-environment. I'm running this configuration, works great. On one part - PI3B+ has the RSP2 connected with USB and running SoapySDRServer. This tools serves the I/Q data stream from the RSP2. On second site I'm running a PI3B with openwebrx, a web based SDR receiver for use with a browser. For other use, I can connect the SDR-Server with CubicSDR, a SDR software for WIN/macos and Linux. All works great together, but you need a stable network speed in range about 10-15 MB/s, depend on selected bandwith of the RSP2 (max. 10MHz). I use CubicSDR with my WIN-notebook, my Macbook Pro with macos and with a 3rd PI2 as Linux-client-minicomputer. In all cases all is running very stable.

Heiko, DL1BZ
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OH2BUA
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Re: Remote RSP via USB/CAT5

Post by OH2BUA » Sat Sep 01, 2018 6:47 am

Ok glovisol sorry,

my viewpoint perhaps too often is avoiding the interference, as I have struggled so much with that subject.

BTW, I use my HiZ input to take signal from Double-KAZ antenna fed by 10 meters long 450 ohms ladder line, tx-safety protection circuit and 2 MHz low-pass filter. I originally constructed them for my RSP2, but plug-and-play switched over to RSPduo.

73, Jukka

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OH2BUA
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Re: Remote RSP via USB/CAT5

Post by OH2BUA » Sat Sep 01, 2018 7:16 am

Heiko,

I agree that the concept You described (IQ stream server) is possibly the most proper way to do the thing.

But, the reason why I'm not using it myself is the requirement for very stable and pretty high capacity internet connection, just as You wrote. I often need to connect from far-away locations with lousy and slim connections. That's the main reason for me to use remote desktop (RDP) style setup instead. That is more liberal with connection quality matters.

73, Jukka

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dl1bz
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Re: Remote RSP via USB/CAT5

Post by dl1bz » Mon Sep 03, 2018 7:51 am

I mean at moment the client-server environment only with a local network (e.g. gigagit ethernet with cable or high speed wifi like ac-based wifi at 5ghz). It's correct, over a internet connection (vpn or so on) you need really much bandwith, which is not so easy for everyone. I use this all with with 2 PI (one as SoapySDRServer and second as openwebrx server - this splits a little bit the cpu usage) running openwebrx - in this case only the audio stream is transported over tcpip and the 2 PI connected together with local network I describe. Look too in this forum in section "code" I show how I work actually.

Otherwise I would say a usb device server is an option - maybe SILEX is a good option (support status for linux I don't know at moment, WIN works, macos too). But you need much bandwith too with network.

Heiko, DL1BZ
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glovisol
Posts: 662
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Location: Piedmont, Italy

Re: Remote RSP via USB/CAT5

Post by glovisol » Wed Sep 05, 2018 1:23 pm

Hu guys,

I judge this info so important I am also posting it in this thread!

Today I received an USB2.0 repeater cable manufactured & sold by LogiLink Germany with a length of 10 m. On Ebay I paid EUR 11.00 for the cable + EUr 7.00 for express courier shipment.

Connected the cable between the PC USB output and the 5 m USB cable coming from my RSPduo.

Switched RSPdu on: the system worked the first time: no RFI, no problems, no fuss. At least 3 cables can be placed in series and this makes for a remoting distance of 35 m, or 115'. Not bad for a total expenditure of EUR/$ 33.00 approx!

Cable manufacturer is LogiLink: http://www.Loglink.de

Cheers,

glovisol

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