[TenTec] 707 wiring

[Jim Brown]

On 10/12/2019 7:04 PM, Bob McGraw K4TAX wrote:
> like most all dynamics, exhibit noticeable proximity effect.

Proximity effect is a characteristic of CARDIOID mics, specifically 
single-D cardioid mics). It has NOTHING to do with whether the mic is a 
dynamic or a capacitor (true condenser or electret). A cardioid mic has 
a pattern similar to a 2-el Yagi, but in three dimensions.

Al Kahn, the founder of Ten Tec, also founded ElectroVoice with Lou 
Burroughs in the '30s. When Lou wanted to retire, they sold the company, 
and Al took his share to start Ten Tec, across the street from EV's 
factory in Sevierville where they built microphones, among other things.

One of those mics was the 666, also known in the broadcast world as the 
"Buchannon Hammer," because Lou demonstrated its ruggedness by using it 
to pound a nail and EV's management was in Buchannon, MI. That mic was 
their first "Variable-D" mic. Single-D cardioids work by interference of 
sound arriving at the front and a single rear port, wavelength effects 
create the pronounced bass boost for very close sound sources (the 
mouth, or a musical instrument) called proximity effect. Variable-D mics 
overcame this limitation,  with additional rear openings providing very 
little bass boost. Current production variable-D mics are the EV RE16, 
RE18, RE20, RE320, and RE-27N/D. I don't know if Shure still makes 
theirs, the SM53 and SM54. AKG used to make a D224. I still own a D224 
and several RE16s and RE20s. All variable-D mics are dynamics.

73, Jim K9YC