[Elecraft] KX3 Audio Power

[Vic Rosenthal K2VCO]

I've always been able to eliminate RFI in amplified computer speakers by 
wrapping as many turns as I can get of the audio and power leads around 
ferrite toroids.

The problem I've had is that they sound awful, especially with CW. They 
tend to buzz at particular frequencies. Maybe I've just had bad luck 
with the ones I've tried.

On 3/28/2014 10:56 AM, Doug Person wrote:
> This has been a significant problem for the powered speakers I have
> tried.  Even the West Mountain Radio speakers that are supposed to be RF
> proof are not RF proof.
>
> I'm going to try a few of the single-ic audio chips to see I can produce
> enough clean audio while avoiding the RF feedback problem.
>
> Doug -- K0DXV
>
> On 3/27/2014 11:47 PM, Jim Brown wrote:
>> On 3/27/2014 6:02 PM, Ross Primrose N4RP wrote:
>>> Just use a pair of small amplified computer speakers
>>
>> Be careful about that -- most amplified loudspeakers have RFI problems.
>>
>> Remember that the KX3 is specifically designed to be a backpacking
>> rig, so everything, including the audio amp, is designed to be stingy
>> about using battery power.
>>
>> One simple thing we can do to maximize the audio output level is to
>> use RXEQ to roll off the lower three bands. The sound in these lower
>> bands makes no contribution to communications, but it does use power,
>> so when we get rid of it, we can use the power for the sound that
>> matters.
>>
>> 73, Jim K9YC


-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/