Buzzing: is my new recorder defective?

[coyote]

I've uploaded a 37-second FLAC to
https://drive.google.com/file/d/0B30bTP7tlQXOVThmOE5XRExIMTg/view?usp=sharing

During a 90-minute recording of a speaker last week, at times there was buzzing, the worse of which is in the 37-second FLAC linked above.

It was the first time I used my new TASCAM DR-05. It was less than a foot from a smartphone someone sat down with in the middle of the talk; could that be the culprit?

I recorded birds at sunrise in my backyard yesterday with the same settings (24-bit 44.1kHz .wav), and never got buzzing.

Is my cellphone theory sensible, or should I exchange the DR-05 to Amazon?

 

[Gravity Jim]

It was less than a foot from a smartphone someone sat down with in the middle of the talk; could that be the culprit?
Is my cellphone theory sensible, or should I exchange the DR-05 to Amazon?

Absolutely. The phone doesn't even have to be in use: if it has WiFi or Locations Services turned on, it will send a signal every now and again, searching for a hot spot, and continue that signal until a connection it likes is made. That signal will infiltrate your recorder.

 

[coyote]

Thank you VERY much, Gravity Jim, that's wonderful to know!

Any guesses on how far from the recorder a smartphone needs to be? (I only have a dumb cellphone so I can't test this myself.)

 

[Gravity Jim]

Not a clue. I suppose it depends on the phone and your recorder. In the situation you describe there's not much you could do, but in a situation where your recording is the main event (a pro gig where you've been hired to record someone in the field, for example), you could ask people with smartphones to stay out of the room.