[Elecraft] K3 TX DATA EQ <was> Re: K3 RX AUDIO

[Jim Brown]

On 7/24/2013 10:59 AM, Sam Morgan wrote:
>
> Do we need another separate EQ setting for Data Audio in the software? 

At the beta test stage for the K3, it was learned that the audio 
transformers, which are unshielded, can couple a strong magnetic field 
into the audio circuits (most often from a big power transformer located 
on a shelf above or below the K3). I experienced a mild case of this 
myself, and my neighbor, K6XX, now an engineer at Elecraft, had enough 
coupling that the K3 regenerated the field and locked in TX.

Wayne and I talked about this. My first recommendation was to ditch the 
transformers, which are completely un-necessary if all the gear in the 
station is properly bonded together. Probably for marketing reasons 
(because most hams are convinced that transformers are needed), Elecraft 
chose my second suggestion, which was to program the TXEQ to roll off 
the low end sharply, with a cutoff on the order of 250 Hz.  So, last I 
heard, that's what's in place for analog data modes.

73, Jim K9YC