(meteorobs) Nikola Biliskov -JGR-ephones

[stange34 at sbcglobal.net]

I am considering installing a metal diaphram PM, or crystal microphone in 
the Meteor Electriks research program to compare with any measures, but am a 
little puzzled by the apparent 180 degree (signal phase shift) of your two 
recordings if both microphones were oriented in the same directions.

It does not appear from your data that the paper & foil contributed to any 
differing characterization of the open & electrophonic recordings. Only 
ambient noise was reduced likely by the sound absorbing material. Do you 
agree?

Other Meteor enthusiasts may well be interested in pursuing a microphone 
option in their studies.

Thankyou, Larry
YC Sentinel


----- Original Message ----- 
From: "Nikola Biliskov" <nbilis at irb.hr>
To: "Global Meteor Observing Forum" <meteorobs at meteorobs.org>
Sent: 2007/04/03 00:49
Subject: Re: (meteorobs) Nikola Biliskov -JGR-ephones


>2 questions regarding the 1998 Mongolian field research.
>>
>>1)  Were the open & electrophonic microphones wired & checked for 
>>identicle
>>phase from a sound source prior to the recording of data in Fig.1 and 
>>Fig.2
>>graphs of the JGR paper?
>
> When the electrophonic microphones were put in the acoustically isolated
> boxes, we hit each box with a stick and recorded the signal both from the
> electrophonic and from the open microphone. The delay of the sound between
> these two channels corresponded well to the distance of about 20 m between
> the microphones.
>
>
>> >2)  Was the paper & foil in contact, (i.e., sandwiched) together or 
>> >loosely
>> >hung in front of the electrophonic microphone without paper & foil 
>> >touching
>> >each other?
>>
> Paper & foil did not touch each other, but they were loosely suspended on
> threads and the microphone was just in between
>
> ---
> Mailing list meteorobs: meteorobs at meteorobs.org
> To UNSUBSCRIBE, email: owner-meteorobs at meteorobs.org
> http://lists.meteorobs.org/mailman/listinfo/meteorobs
>