[Elecraft] K3 8khz wide sig tracks VFO A ~30khz lower in frequency

[Phil Wheeler]

Eric,

Re "Also, if you have an extra BNC-BNC cable, try 
replacing this cable.": Really!  Yesterday I was 
testing a newly received mag mount to make sure 
this (MFJ!) product was OK. Connected a dummy load 
to it via a BNC-BNC connector and VSWR was not 
flat and impedance varied significantly with 
frequency.  Changed dummy load: Same result.

As it turns out the problem was in the BNC-BNC 
cable, not the device I was testing. Verified by 
mounting one of the Elecraft dummy loads direct to 
the mag mount, then via a different cable which 
was OK.

BTW -- the BNC-BNC mag mount is for use with the 
MFJ 18XX-T whips, so I can mount them remote from 
my KX2/3 vs. always on the rig with rt angle BNC 
adapter.  Seems like a good option to have, since 
I have two of the whips (20 and 40)!

73, Phil W7OX

On 6/9/16 8:45 AM, Eric Swartz - WA6HHQ, Elecraft 
wrote:
> Check the connections on the BNC cable between 
> your K3 and P3 and re-seat them. Also, if you 
> have an extra BNC-BNC cable, try replacing this 
> cable.
>
> Also, if this BNC is run near switching power 
> supplies etc. it can pick up noise like this.
>
> 73,
> Eric
> /elecraft.com/
>
> On 6/8/2016 7:22 AM, Sam Morgan wrote:
>> I have a 8-9 khz wide signal that follows my 
>> VFO A around. I saw this on 160m and also in 
>> 10m this morning. I haven't checked the other 
>> bands.
>>
>> Images can be seen here:
>> https://picasaweb.google.com/k5oai.sam/6293813435183959297 
>>
>>
>> No antenna was connected to the K3. The only 
>> cables connected to the P3 were: Coax and RS232 
>> from K3. I attached the RS232 to the computer 
>> to get the snap shots, bet the signal did not 
>> change with it connected to the computer or not.
>>
>> Note: During the snapshots I bumped the VFO 
>> knob from 28.120 to 28.119.40 by mistake during 
>> the snapshots, but that doesn't have any effect 
>> on the fact there is this big wide scary 8-9khz 
>> wide signal ~ 30 khz down from VFO A that is 
>> tracking my main VFO.
>>
>> What is going on, has my K-Line been invaded by 
>> something? If so what and how do I fix it?