K-2 Transmitted signal distorted (Hum)

[Greg Storms]

I have just started experiencing a tremendous distortion on my
transmitted signal (K-2).  It was first noticed by a SSB
contact.  He said my transmission was strong but nearly unreadable.  I
duplicated it at low and high power on a separate receiver.
It occurs on both SSB and CW.  This happened rather suddenly as I had
contacts the previous day with no problems noted.

Occurs when the KAT-100 is grounded or ungrounded and on different
antennas.  Anyone else had this happen?  Suggestions
as to where to begin looking?

Thanks in advance,


Greg
KD7SRC
K-2 #3434

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[Don Wilhelm-3]

Greg,

It could be any number of things from having an AC transformer located
too close to the K2 (especially on the left side - did you re-arrange
the operating position?) to a bad solder connection somewhere.

We need more detail to even get started.

One thing you may want to check is RFC15 on the bottom of the RF Board.
  Check it with an ohmmeter to be certain it is not open.  If you try to
do it by measuring the voltage on each side of the choke, you will find
5 volts on both sides whether it is open or not.

73,
Don W3FPR

Greg Storms wrote:

> I have just started experiencing a tremendous distortion on my
> transmitted signal (K-2).  It was first noticed by a SSB
> contact.  He said my transmission was strong but nearly unreadable.  I
> duplicated it at low and high power on a separate receiver.
> It occurs on both SSB and CW.  This happened rather suddenly as I had
> contacts the previous day with no problems noted.
>
> Occurs when the KAT-100 is grounded or ungrounded and on different
> antennas.  Anyone else had this happen?  Suggestions
> as to where to begin looking?
>

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[Greg Storms]

Thanks for all the replies!

Not a power supply problem.  Does exactly the same thing when on battery
backup.  Nothing new in the operating position to create a problem.  
RFC15 is *NOT* open.  There is 5 volts on both sides of it.

Don Wilhelm wrote:

>
> One thing you may want to check is RFC15 on the bottom of the RF
> Board.  Check it with an ohmmeter to be certain it is not open.  If
> you try to do it by measuring the voltage on each side of the choke,
> you will find 5 volts on both sides whether it is open or not.
>
>
>
> Greg Storms wrote:
>> I have just started experiencing a tremendous distortion on my
>> transmitted signal (K-2).  It was first noticed by a SSB
>> contact.  He said my transmission was strong but nearly unreadable.  
>> I duplicated it at low and high power on a separate receiver.
>> It occurs on both SSB and CW.  This happened rather suddenly as I had
>> contacts the previous day with no problems noted.
>>
>> Occurs when the KAT-100 is grounded or ungrounded and on different
>> antennas.  Anyone else had this happen?  Suggestions
>> as to where to begin looking?
>>
>
>
>
>

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[Don Wilhelm-3]

Greg,

You must check RFC15 with n ohmmeter to determine if it is open or not.

Even if it is open, there will be 5 volts on both sides of RFC15.

73,
Don W3FPR

Greg Storms wrote:

> Thanks for all the replies!
>
> Not a power supply problem.  Does exactly the same thing when on battery
> backup.  Nothing new in the operating position to create a problem.  
> RFC15 is *NOT* open.  There is 5 volts on both sides of it.
>
> Don Wilhelm wrote:
>>
>> One thing you may want to check is RFC15 on the bottom of the RF
>> Board.  Check it with an ohmmeter to be certain it is not open.  If
>> you try to do it by measuring the voltage on each side of the choke,
>> you will find 5 volts on both sides whether it is open or not.
>>
>>
>>
>> Greg Storms wrote:
>>> I have just started experiencing a tremendous distortion on my
>>> transmitted signal (K-2).  It was first noticed by a SSB
>>> contact.  He said my transmission was strong but nearly unreadable.  
>>> I duplicated it at low and high power on a separate receiver.
>>> It occurs on both SSB and CW.  This happened rather suddenly as I had
>>> contacts the previous day with no problems noted.
>>>
>>> Occurs when the KAT-100 is grounded or ungrounded and on different
>>> antennas.  Anyone else had this happen?  Suggestions
>>> as to where to begin looking?
>>>
>>
>>
>>
>>
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> Elecraft mailing list
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> You must be a subscriber to post to the list.
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>
>

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