[Boatanchors] Need Microphone Information

[Richard Knoppow]

----- Original Message ----- 
From: "David C. Hallam" <dhallam at knology.net>
To: <boatanchors at mailman.qth.net>
Sent: Thursday, May 19, 2011 6:01 AM
Subject: [Boatanchors] Need Microphone Information


>I am looking for ideas for a microphone to use with my 
>SBE-33
> transceiver.  The microphone supplied with the SBE-33 was 
> a Turner
> SR-90D hand-held  which is a high impedance dynamic 
> microphone with -48
> dB output.  I would like to replace it with a desk 
> microphone.  I have
> tried several high impedance dynamic microphones, the 
> latest being a
> Electro-Voice 619, but their output is generally too low, 
> around -57 dB,
> to drive the SBE-33.  The audio system of the SBE-33 
> evidently has very
> little gain.  Even with the SR-90D I have to set the audio 
> gain control
> to about 60-75% of full output.
>
> I know I could use a microphone preamp, but that would 
> just add another
> box to clutter the operating desk.
>
> Does anyone know of a desk style high impedance dynamic 
> microphone with
> high output?
>
> David
> KW4DH

     I am not familiar with the SBE-33 so I don't know if 
yours is working as it should. There are not many 
unamplified mics with such high output but the famous D-104 
is one. The crystal version is rated at -45db.
     Keep in mind that with a hand-held you are usually 
using it very close to your mouth so the output is going to 
be quite a bit higher than a mic used at a distance on a 
desk. Average level from high impedance mics is 
around -55dbV, the mic preamp in the rig should be designed 
to work from a mic of about this level.
     FWIW Turner made a great many OEM microphones for 
Collins and other manufacturers, usually they can be 
identified by appearance.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com