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2. Re: Initial SASS test shows bands of harmonics

Subject: 2. Re: Initial SASS test shows bands of harmonics
From: "Mike Rooke" picnet2
Date: Tue Mar 13, 2012 3:40 am ((PDT))
Is the cable you are using fully screened? I've noticed some recent cables =
skimp on the copper shield/braid which means its not fully screened.

The same banding / spectral peaks I see when using headphone cables connect=
ed to the capsules for binaural recording - those are not screened. With a =
screened cable Ive never seen*1 such lines except with the LS10.

If the cable is screened and the capsule is "ok" then I'd check how close t=
he cabling is to the M10s LCD and re-route it.

-Mike.
*1 > 300 capsules soldered, abused and destroyed in one form or another.

--- In  Luis do Carmo <> wrote:
>
> The M10 has a speaker and so a magnet in its body. Even if the speaker is=
 not in use, the magnet produces a magnetic field of its own.
>
>
> Luis
>
>
>
> ________________________________
>  From: Peter Shute <>
> To: "" <>=

> Sent: Sunday, March 11, 2012 4:09 PM
> Subject: RE: [Nature Recordists] Re: Initial SASS test shows bands of har=
monics
>
> The clipped noise is from me handling the array as I wrap the towel over =
it.
>
> I've just proven it's interference from the M10. With the recorder on top=
 of the array , the effect is reproduced. With the recorder upside down it'=
s even stronger. With the recorder inside the array, pressed again the wiri=
ng between left and right under the top, it's very strong, and I can clearl=
y hear the hum from it.
>
> Interestingly, with it insdie, pressed against the cable but upside down,=
 the effect is nowhere near as strong. Thus, the interference is coming fro=
m
>  underneath the M10.
>
> Even 1m away, I can see the regular spikes on a frequency analysis, but i=
t's too weak to see on the spectrogram.
>
> Just to be sure it's electrical interference, not acoustic, I held it in =
front of the mics, 1cm away, and the effect is weak. Therefore it's electri=
cal interference from underneath the M10.
>
> The effect is on both channels, but is far stronger in the right channel,=
 I assume because I ran the wireing from the right over to the left before =
joining to the cable I plug into the recorder, and so there are a few more =
inches of wiring on that channel.
>
> But perhaps Raimund is right, that it's caused by the PIP struggling with=
 4 capsules. Can anyone recommend a battery circuit I could try? I was goin=
g to look into this anyway. Is it safe to just put a voltmeter across a cap=
sule to check it?
>
> Now to get out of this house, and try some more tests at sunrise.
>
> Peter
>  Shute
>
> ________________________________
> From:  =
 On Behalf Of Raimund 
> Sent: Monday, 12 March 2012 4:46 AM
> To: 
> Subject: [Nature Recordists] Re: Initial SASS test shows bands of harmoni=
cs
>
>
>
> Because the noise obviously starts on the first occurence of the broad-ba=
nd and clipped noise (which does not seem to be an acoustic signal), I woul=
d guess that it might have something to do with PIP power
>  provided by the recorder. It could be that the PIP supply circuitry just=
 does not work properly due to the heavy load by the four capsules. So, you=
 might try to power the capsules by an external battery.
>
> Raimund
>
> --- In <naturerecordists%40yahoogr=
oups.com>, Peter Shute <pshute@> wrote:
> >
> > The link to the sonogram image works now. The album wasn't set for publ=
ic viewing, I assumed that setting was the default. Sorry about that.
> >
> > https://picasaweb.google.com/pshute2/March112012#5718478097647090786
>
>
>
>
>
> ------------------------------------
>
> "While a picture is worth a thousand words, a
> sound is worth a thousand pictures." R. Murray
>  Schafer via Bernie Krause.
>
> Yahoo! Groups Links
>
>
>
>








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