Received-SPF: neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) client-ip=195.171.43.25;
Message-ID: <C662FF2CDFAA40A59F40DAFEDDF73CF2@AGB>
From: "Graham" <g8fzk@g8fzk.fsnet.co.uk>
To: <rsgb_lf_group@blacksheep.org>
References: <BLU180-W3599B1565E284475140856AC880@phx.gbl> <2662DF5AA7FA416CBB09CDB90BBFF7B1@White> <016101cf39df$4f4c89a0$ede59ce0$@comcast.net> <FA723BF050144798AD076EB0C9190D21@White> <BLU180-W432C6E6C028F0DD53D7014AC8B0@phx.gbl> <01dc01cf3a3f$86997bb0$93cc7310$@comcast.net> <A47BA5540C3B42619C724008CDF3A0ED@White> <BLU180-W23A00B5028E9D0DEEF6B3AC8B0@phx.gbl> <2FC5CAB271A6437CB35A5B100185CEDA@White> <025101cf3a52$e0925750$a1b705f0$@comcast.net> <7DB9DD5669FC4C648838510DCAC08AFB@White> <531A506E.9040103@abelian.org> <531A5C19.9060209@abelian.org> <02ba01cf3aa3$debaad50$9c3007f0$@comcast.net> <531AF126.2060600@abelian.org> <850A470A5B9F4483BED8B49D4791044A@White> <531B1D0C.3070208@abelian.org> <531B2478.70500@iup.uni-heidelberg.de> <E1WMJBw-0004O4-Nt@post.thorcom.com> <531B796A.9000906@iup.uni-heidelberg.de>
In-Reply-To: <531B796A.9000906@iup.uni-heidelberg.de>
Date: Sat, 8 Mar 2014 20:21:58 -0000
MIME-Version: 1.0
Importance: Normal
Subject: Re: LF: Microphone via WLAN (WiFi) ?
Content-Type: text/plain;
	format=flowed;
	charset="iso-8859-1";
	reply-type=response
Content-Transfer-Encoding: 8bit
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org

Surely  the  dynamic  range is  defined by the  a/d  in the  sound  card 
...... ? the  wi-fi  link should  only mimic the  USb link ?
its  only  in  compression modes that  all  sorts  of  adjacent  tones  and 
dynamic  range are limited  ? a wave file  is raw  data  ?


PC in the  link .......  dont  know , but  if the  wi-fi  simply  extended 
the  USB  distance  , then  , would  not the  driver be  at the  end of the 
link ? as in the post ?

G,

--------------------------------------------------
From: "Stefan Schäfer" <schaefer@iup.uni-heidelberg.de>
Sent: Saturday, March 08, 2014 8:11 PM
To: <rsgb_lf_group@blacksheep.org>
Subject: Re: LF: Microphone via WLAN (WiFi) ?

> Hello Mauro, Clemens, Graham,
>
> Your examples are in principle what i need but in these systems, the 
> dynamic range is much to low, maybe 40...50 dB. Some years ago i played 
> arround with some Bluetooth headset, which has a microphone input of 
> course. But the results were very poor.
>
> Also, the backgound noise reduction is an unwanted feature here, as well 
> as an AGC.
>
> I think, i the todays world, it should be "easy" to combine a SMD ADC 
> (those from the cheap soundcards) with a SMD WLAN IC (those from the cheap 
> USB WLAN adapters, giving some 10 mW to some 100 mW output power). But i 
> don't know anything about the communication between these 2 ICs, 
> protocols, configuration, etc. etc.
>
>
> Am 08.03.2014 16:21, schrieb Graham:
>> [...]
>> MIC <>  USB SOUND  CARD <> USB/WIFI ~~~~~~~ WIFI/USB<>PC
>
> But you did forget something! Actually you must write:
>
> MIC <>  USB SOUND  CARD <> PC/Netbook <> USB/WIFI ~~~~~~~ WIFI/USB<>PC
>
> And this is what i don't need. The power consumption, weight, size, costs 
> are to high and a PC is not necessary.
>
> But now i found this: 
> http://www.amazon.de/Kamera-%C3%9Cberwachungskamera-Empf%C3%A4nger-Zubeh%C3%B6r-Wireless/dp/B004AZL6AE/ref=pd_cp_ce_2
>
> It is a WLAN camera+ audio. Actually i don't need the camera, just the 
> tone. The remote system runs on batteries, just as i need. Maybe the 
> camera can be removed or disconnected. The question is, what is the 
> dynamic range and frequency range (0...24 kHz?, maybe not!) and are there 
> any "sound effecs" which are unwanted here. 49 EUR, that would be fine if 
> it works as desired. Maybe the audio chip could be replaced by a better 
> one?! But maybe it is all in one...
>
> Has someone ever played with such a system or are there alternatives that 
> i didn't found so far?
>
> Sounds like OT but such a system could be a revolution for LF/MF/VLF 
> reception, when thinking about local QRM problems!
>
> 73, Stefan/DK7FC
>
>
>
>
>
>
> Am 08.03.2014 16:29, schrieb IK1WVQ Mauro:
>> Hi Stefan
>> it is not completely compliant to your requests, but, if you do not find 
>> the right equipment, you can consider the "baby monitor" at 860 MHz .. 
>> some units are digital, and you can route the sound output to the line 
>> input of the sound card of your PC .
>> In free space, without antennas, you can obtain near 300 meters..
>> the system is "near" legal (you can consider your new VLF receiver as a 
>> "baby" !!! hi!)
>>
>> 73 de Mauro IK1WVQ
>>
>> At 15.08 08/03/2014, Stefan Schäfer wrote:
>>> Hi all,
>>>
>>> Again i spent some time to find a module which allows to transfer a 
>>> mircophone input signal via WLAN to the PC. Without success...
>>>
>>> To make things clear:
>>>
>>> The system has to consist of to parts:
>>>
>>> 1: The first one is battery supplied and has a microphone input (like a 
>>> cheap external USB soundcard) and a WLAN output, using an external 
>>> antenna and SMA plug. I.e.: Input: 3.5mm microphone jack. Output: SMA 
>>> WLAN antenna connector.
>>> 2: The second part is connected to the PC and is a WLAN receiver that 
>>> appears as a normal external USB soundcard and allows to receive the 
>>> audio signal from the first part of the system.
>>>
>>> The system allows to run a /p receiver for VLF or any other band.
>>>
>>>
>>> An expert could create such a circuit for himselfe but i need to buy 
>>> something like that, if it is available. But all i can find in the web 
>>> is the opposite way, i.e. people who want to transfer their sound from 
>>> the PC to a /p loudspeaker or headphone, argh...  Or, a big device which 
>>> includes a real big microphone (dynamic range ???). These are expensive 
>>> systems.
>>>
>>> However, external soundcards are cheap and WLAN modules are cheap too.
>>>
>>> So, isn't there such a device for a few EUR in the web, these days? It 
>>> has to have a dynamic range of  at least 100 dB, like the 2 EUR external 
>>> soundcards at amazon do (with some luck).
>>>
>>> Any help is much apprechiated :-)
>>>
>>> 73, Stefan/DK7FC
>>
>>
>