[Elecraft] K3 has internal noise with high compression settings

[goldtr8 at charter.net]

Hi Don,

First I agree that that is not a normal setting to run that high. 
Normally I only have it in the range between 10 to 20 mostly at 15 like 
you do.

I did the experiment as when the antennas were hooked with the RF 
issue, I found that dialing down compression to under 10 sometimes 
helped reduce the RF triggering.

So as stated I wanted to find the boundries when connected only to the 
dummy load.   The part that it showed power output at that high level of 
compression is not that suprising.

What concerns me is that I clearly heard internal to the K3 something 
like a ferrite buzzing.  I put my ear directly on the top of the case to 
listen and this buzzing was internal.

I only want to know could this be considered normal.

Or if there is an internal component problem and my K3 is more sensitive 
to RF issues than normal which is contributing to my problems.

~73
Don
KD8NNU


On Thu, Jan 12, 2012 at 1:26 PM, Donehrlich at q.com wrote:

> Don,
>
> My first reaction is that compression of 35 is way too high.  I never 
> go over 15 or so because of all of the background noise in the shack 
> that is picked up by the mic at high compression settings.  Something 
> of that sort is perhaps what you are hearing .. maybe a fan or other 
> hum-like sound in the local environment.  High compression makes the 
> system super sensitive to low level sounds.
>
> Don K7FJ
>
>
> On 1/12/2012 9:58 AM, goldtr8 at charter.net wrote:
>> Gents,
>>
>> Last night I disconnected all the antennas and started to look at 
>> basics
>> within the shack because of my antenna problem, I decided that I 
>> should
>> check the basics with my dummy load and found an interesting thing
>> happening inside my K3.
>>
>> What I found is that when directly connected to a dummy load and I 
>> run
>> the k3 at full power 110 watts, as I dial up the compression above 35 
>> on
>> the settings , I hear a hum inside the K3 and it shows RF out power 
>> in
>> SSB when I am not speaking into the microphone.  Basically key up the
>> mike in a quite environment in SSB mode and it goes into TX where 
>> there
>> is output.
>>
>> I made a coax choke with snap on ferrites between the dummy load and 
>> the
>> K3 to see if I could kill it but it made no difference.  Also power
>> settings below 110 did make some difference and mike gain had little 
>> to
>> no effect.  This happens on all frequencies, does not matter if on 
>> 160m
>> or 10m.
>>
>> I then connected the amp between the K3 and dummy load and this noise
>> starts at about a compression setting of 30 to 33.  This is with a 
>> drive
>> power of 40 watts into an SGC powercube, and when the humming started
>> there was TX power on my meter.
>>
>> The internal noise sounds like a ferrite vibrating.
>>
>> Other items, power is supplied via 12v batteries using a floated 
>> battery
>> charger, existing antennas were disconnected from the system.
>>
>> Is this something that others have seen or should I call Elecraft
>> support.  I am hoping I don't also have a K3 problem.
>>
>> Thanks
>> Don
>>
>>
>> ~73
>> Don
>> KD8NNU
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