RF Spectrum analyzer for less than $50US

[peterskine]

Jim Bay from the Met is subbing for me on the Million Second Quiz and introduced me to this RF Spectrum analyzer

 

The PC USB Tuner and BNC cable are available on Amazon or eBay for less than $50 (BNC cable costs more than tuner!). RF range is 25MHz-1700MHz for software defined radio (SDR).

 

RTL2832U Dongle

BNC adapter cable

Software Defined Radio - SDR# Software is free

Also, thankfully, Zadig has an automatic

driver download and install program

The program seems to be written for Hams and lacks some obvious SA controls like Span but does have a nice responsive display with waterfall and several kinds of demod through your laptop speaker just by clicking on a carrier. This alone is terrific.

 

It is only for looking and listening to one carrier at a time.

 

" the TV dongles have a typical maximum usable sampling frequency of 2.4 MHz, allowing a display approaching +/- 1.2 MHz." When it was all choppy yesterday I was pushing the sampling rate to 2.8 or 3.2mhz and I guess it's the dongle that can't do it, not the PC.

Specs

 

so, no substitute for a real SA for doing a site survey, but an awesome toss-it-in-the-bag tool. There are a few different versions with variations in chipsets, I think the E4000 chipset goes higher into UHF with lower sensitivity but I'm not that up on the details.

[pjb304]

We've got a couple at work now, and they are great. We also have a 'proper' spectrum analyser and radio scanner, but it's a useful extra tool in the pocket.

[paulears]

I got one of the dongles for 7 quid! Amazing value. Ordered the day this topic was posted, arrived today from Hong Kong.

[Peter F]

I got one of the dongles for 7 quid! Amazing value. Ordered the day this topic was posted, arrived today from Hong Kong.

 

I splashed out £11. To save anyone else the messing about, it doesn't work with Windows 8. Maybe someone can work their magic with the drivers. Works great with earlier versions of Windows though. Would highly recommend this for anyone faffing with RF. To be honest, anyone slightly geeky is going to have fun with one of these, a quick look at what comes out of the possibly faulty AKG radio pack that I had to hand was a bit of an eye opener.

 

Cheers,

 

Peter

[paulears]

Indeed! I'm old enough to remember when the film Convoy started people importing 27MHz CB radios and doing the UK version of the rubber duck, good buddy thing (which, with an East Anglian Accent, as pretty funny) - and somebody brought me one they had tweaked to give more output to look at. They'd turned trimmers until they had maximum output on their 'swarrr' meter. There was indeed plenty of output, very little though where they wanted it. I tried a mic pack hanging about and it seemed sproggie free, but a little AKG guitar bug on the shelf that I've used occasionally was pretty different - lots of quite strong outputs - which perhaps explains why it sounds good, but is quite cheap. I guess it's tiny size precludes much in the way of filtering!

[paulears]

Has anyone managed to get this working on a Mac, via Parallels. Mine cannot see the driver, although parallels can?

[bruce]

This post is a couple of years old now. Are there better products on the market at this price point, or are the links above still the ones to look at?

The software download has moved too....

[paulears]

The dongles are amazingly popular for people who want to decode digital comms. SDR+ and the digital decoder work pretty well as analysers, but they have lots of sproggies and audio quality is somewhat unpleasant - but they're certainly doing business.

[bruce]

So I decided to buy one. Then I remembered I already had one of these units in my office drawer - had been experimenting with using it as a DAB receiver....

 

The software has moved - to http://airspy.com/download/

Download and unzip the “SDR Software package”.

Then follow the instructions on http://www.rtl-sdr.com/rtl-sdr-quick-start-guide/ - basically you run the install-rtlsdr.bat script, which downloads some driver tools, plug in the dongle, run “zadig.exe” to install and configure the drivers, then run the “SDRSharp.exe” application. Switch the source to be “RTL-SDR(USB)” and press “play”....

 

Quite impressed so far....

[peterskine]

This post is a couple of years old now. Are there better products on the market at this price point, or are the links above still the ones to look at?

The software download has moved too....

 

More SDR radios: http://www.hamradios...nd-2016-so-far/

 

software: http://www.pe0sat.vg...tware/sdrsharp/

 

Freespeak DECT Monitor: Revolabs 01-DECTMTR-01

Software download link;

http://www.revolabs.com/getattachment/efe99a00-76f0-4052-9603-7f221ae13342/DECT-Monitor-Software-Download

Edited June 26, 2016 by peterskine

[sandall]

I'm probably being dense here (it's the outdoor season & I'm feeling old), but to give me a RF spectrum analyzer for 170-ish MHz & Ch.38-70, do I just need one of the SDR dongles mentioned above, a bit of free software & a laptop, or is there a lot more to it than that?

[paulears]

Well, no - that really is it. The only drawback is the audio quality isn't brilliant, and it does indicate some spurious signals that aren't there - but in general it actually does a decent enough job. Filtering is a bit iffy - so the front end is wide open, but that makes it useful. As the software is the key, you can do all sorts with them. I'm trying to get mine to decode digital comms, but it's a bit fiddly - I'll get there in the end.

[sandall]

Well, no - that really is it.

I hope so - I've just ordered the RTL one - just under £13, inc. carriage (would have saved a £ or so if I'd ordered before Brexit, as it's priced in USD). In theory they are about $10.80 with free carriage, but that seller won't ship to UK.

 

Thanks, Ian

[vlfaudio]

To be honest, anyone slightly geeky is going to have fun with one of these,

 

Geeks have been having fun with these for a couple of years now

[sandall]

Well, no - that really is it.

Not impressed with 3-weeks shipping from US (though it actually arrived in nearer 2), having just had some DMX stuff arrive from Hong Kong (with free shipping) 4 working days from order, & the set-up guide isn't the clearest I've ever met, but most impressed once I'd got it working. Next task is to get it working with XP.

 

2 questions - is there a frequency offset I haven't discovered (all my radio-mics appear to be slightly off-frequency), & is there a way of displaying a wider frequency range (ideally a whole TV channel) ?