[Elecraft] microHAM K3 cables ...

[Joe Subich, W4TV]

> I was under the impression that the K3 was wired the same as 
> Kenwoods for microphone usage.  However, In checking the Heil 
> website, and the subsequent link for mike connections, they 
> show that pin 5 is 8 V., whereas the K3 manual shows that pin 
> 6 should have 8 V.

Correct, I had not noticed the error but just compared the 
Elecraft FAQ vs. the TS-2000 manual and Elecraft show pin 6 
for bias and pin 5 as "Func" while the TS-2000 manual shows 
pin 5 for bias and pin 6 as "NC." 

This means that a Kenwood electret mic will not work with the 
K3 unless the microphone is modified. 

> I'm also curious why my Heil Pro Set headphones seem to have 
> low output compared to other headphones on various rigs that 
> I own.   Anybody know what the impedence is for the headphones?

The original ProSet had 200 Ohm earphone drivers.  A modification 
replaced those with 32 Ohm units (I think).  The "low output" is 
due to the reduced output of most amplifiers when driving high 
impedance loads - Yaesu even includes 10 Ohm resistors in series 
with the headphones to prevent excess volume in the headphones!  
Of course, the higher impedance headphones (and series resistance) 
helps cut down the hum, hiss and distortion. 

73, 

   ... Joe, W4TV