Using SONY ECM-21 Mic on AM or SSB? (longish...)

DavidC eDoc at NETZERO.NET
Sun Dec 19 09:48:51 EST 1999

Thanks to all who replied!  Very helpful!  Beautiful sounding
AM, here I come!  ;-)

Neat thing about the ECM-21 is that it requires only a standard
1.5v AA battery and the compartment is inside the mic casing.

Of course the down side is if the battery leaks your mic will
probably be destroyed.  Short term I will use the AA, long term
I will probably rewire the mic to accept power from the mixer
or rig.

I continue to be interested in recommendations for a mic pre-amp/
EQ/limiter-compressor device that I might acquire used for short
money.  Would also appreciate suggested sites on the Internet
where such devices are commonly posted for sale.

Keep making those BA's sound better and better!  ;-)

- Thanks again! & 73, DavidC  K1YP

> Hi David,
> While I'm not familiar with the Sony ECM-21 mic, you might enjoy
> "tailoring/shaping" the mic's audio with a simple preamp design from the
> ARRL Handbook. Check out the 1998 version, 22.30, chapter 22. The circuit
> easily-built on a breadboard, and employs a 2N3904 and a 741 op-amp. It
> hi-boost, low-boost and a mic gain control that should cover a reasonably
> wide range of mics/rigs. I've played with a number of mics using this
> circuit. Cost is about $5-$10 depending on the depth of your junque box :)
> As you probably know, the ironic "goal" in creating the ultimate SSB
> contesting mic, is to roll-off the mic's high and low-end audio spectrum
> performance and concentrate the sound energy in a narrow range. According
> Bob Heil, of Heil Sound, that range should be ~ 500Hz to 3,800Hz with a 10
> dB rise at 2,000Hz -- which is a freq that the human ear is especially
> sensitive to. By comparison, electret mics that are used for hi-fidelity
> recording have ranges of perhaps 30Hz to 18kHz ! So, you'll probably need
> get rid of a lot of the Sony's stunning performance to make it a good SSB
> mic ;)
> AM mics -- depending on who you talk to -- are a different breed. With the
> higher bandwidth of the AM signal, most ops want all those deep rich lows
> and twinkling highs ;) So, that's a scenario that's more naturally suited
> the Sony's frequency response -- right out of the box. Should work pretty
> well; might have to use a small preamp, depending on your rig.
> Regarding used mixers/preamps -- I own a Mackie 1202 -- which is a lot of
> fun to play with, although I'd consider it *excessive* for ham radio mic
> work. Doesn't hurt to check around and see what the local music shops have
> tho'.
> Heil Sound:
> Mackie Mixer:
> GL with the project,
> 73 - Conrad Weiss - NN6CW

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