[Elecraft] CM500 headset on K3S and KX3?

[Jim Brown]

On 5/6/2020 3:08 PM, Fred Jensen wrote:
> I guess all microphones tend to accentuate the bass as you get closer 
> and closer, exactly the opposite of what you want for communications. 
> Electrets seem to be fairly immune to this, the old classic RCA 44-BX 
> was notorious for the effect.

That's a characteristic of nearly all DIRECTIONAL mics -- those that  On 
provide a single rear opening the capsule to cancel sound from the rear. 
Variable-D mics, virtually all of which today are made by Electro-Voice, 
have multiple openings along the "handle" of the mic body to provide the 
cancellation, and they have very little of that bass build-up. The 
earliest made by EV was the model 666, called "the Buchanan Hammer" 
because EV was in Buchanan, MI, and Lou Burroughs, who along with Al 
Kahn founded EV in the '30s, demonstrated the ruggedness of the new 666 
to broadcast conventions by driving nails with it.

When Lou wanted to retire, they sold the company to Gulton Industries. 
Al took his share and started Ten Tec, across the street from their mic 
and speaker factory in Sevierville, TN.  Al was K4FW. I worked him once, 
on CW, using one of his radios. I was mobile from a campground in AR.

Shure and AKG both made variable-D mics for several decades, but I don't 
think they still do. Modern variable-D mics are the EV RE10, RE11, RE15, 
RE16, RE18, and RE20. Last I looked, only the RE16 and RE20 were still 
in production, but there may be new models since I was active in the 
biz. The RE20 is quite popular as an announce mic.
https://www.electrovoice.com/product.php?id=91

I know of no variable-D electret mics.

5/6/2020 11:39 AM, Walter Underwood wrote:
 > If I was going to upgrade my headset, I’d start with headsets used by 
sports broadcasters and ENG teams.

Those headsets are EXPENSIVE, the mics are low impedance PRO mics, and 
are designed to provide maximum noise rejection. IF they are electrets, 
they won't work with ham gear without a preamp that provides Phantom 
Power (NOT the same as bias).

73, Jim K9YC