[Elecraft] [OT] Heil ProSet K2 with Kenwood TH-D72a HT?

[Don Wilhelm]

Bret,

The Proset K2 has an electret microphone, and needs a bias voltage applied.
So if your TH-D72 does not provide bias for the mic element it would not 
produce audio.

The Heil Proset is available in several models, it is important to state 
which one it is.  The Proset-K2 and the Proset-iC both have electret 
emic elements, while the others use dynamic microphone elements and do 
not need bias (should not have it).

Bottom line, I suspect your Proset-K2 will not work with the TH-D72a. 
If you want to check for certain, turn power on and measure the voltage 
between ground and the AF microphone pin.  If you find a positive 
voltage from 5 to 8 volts, the Proset-K2 will work with the proper 
adapter, but if the voltage is zero, that particular Proset will not work.

73,
Don W3FPR

On 12/25/2017 3:54 PM, MaverickNH wrote:
> My Heil ProSet K2 headset works great with my K3S, of course. I just got a
> used kenwood TH-D72a HT for some satellite fun and wonder if the Heil
> headset will work with the HT? The TH-D72a lists:
> Microphone Impedance	2 kΩ
> Audio Output (at 8 Ω, 10 % distortion)	More than 300 mW (at 7.4 V)
> 
> But I don’t know the Heil specs or if I can get an adaptor. Any help
> appreciated.