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

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k5oai

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

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?

--
GB & 73
K5OAI
Sam Morgan
John 3:16 Ephesians 2:8-9 1 Peter 2:24 Acts 2:38
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Eric Swartz - WA6HHQ

Re: K3 8khz wide sig tracks VFO A ~30khz lower in frequency

Administrator

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?
>

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Help: http://mailman.qth.net/mmfaq.htm
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k5oai

Re: K3 8khz wide sig tracks VFO A ~30khz lower in frequency (SOLVED)

Bingo, finally (3rd cable I tried) found a good cable that cleared up
the problem.

--
GB & 73
K5OAI
Sam Morgan
John 3:16 Ephesians 2:8-9 1 Peter 2:24 Acts 2:38

On 6/9/2016 10:45 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?
>>
>

Phil Wheeler-2

Re: K3 8khz wide sig tracks VFO A ~30khz lower in frequency

In reply to this post by Eric Swartz - WA6HHQ

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?