Tuesday, January 20, 2015

Thoughts on the next bit of test equipment I'd like

Now that I'm just waiting for some small handheld antenna's in the VHF/UHF range to arrive.  I've been thinking how nice it would be to use an Android device that has RF Analyzer installed on it.  This is a VERY COOL app that'll run on Android and connect to RTL SDR, or HackRF One (I have both and have tested it with both, and it seems to work excellent).  

Here is a video of what I'm talking about.  




It's just a quick view of how well this works.  What I'm doing is using a small whip antenna that is good for 50, 144, 432 Mhz on a HackRF connected to my Android phone and running RF Analyzer @ 44.25 Mhz listening to AM Mode and the source of my nearby Power Line noise.

With the combination of being able to take video's, and photo's and being able to use the GPS and RF Analyzer all in one device (well two if you include the RTL or HackRF)...pairing all these tools up to be used as a portable RF noise sniffer, and recording device seems like the next logical step.

  • RF analyzer paired up with a portable Arrow antenna and a HackRF to visualize the noise, as well as listen to it!  (YES the RF Analyzer app now can demod the audio, AM, FM, WBFM, SSB etc).
  • Photos and video from the Android Camera (gps linked)
  • On board GPS
On thing I've noticed about the HackRF is that holding it snug against the back of my Galaxy S3 increases the noise floor a fair amount.  So it's well know (I think) that the HackRF's case which is crap for RF shielding.  So I'll probably build a little Copper Clad PCB box to wrap around it or use some copper tape!  LOL

Anyway I'm envisioning all of this equipment mounted to the back of the VHF/UHF antenna, and while on site at a known noisy location all of this combined could help document a problem area.

The biggest issue I've had in the past with Power Noise tracking is the part where you need to document things each time.  With enough detail to be useful in debugging a problem.  Using all of this combined would make is as simple as waving your arms around with the gear doing all of the recording and minimal interaction required on the part of the user at the time.

This is also important from a safety standpoint.  For example you could actually be looking where you're about to plant your feet, or on coming cars, or big dogs, or downed power lines :-)  All kind of important!

The last time I'd used RF Analyzer it didn't include demodulation of the audio.  NOW it does and it CLEARLY works wonderfully!  Especially in AM mode which is helpful in power line noise hunting.

More to follow on this as soon as I've been able to video the operation of this...shouldn't be too long, I'm just waiting for my other android to charge up :-)