K2/100 RF output varies

[Mike Short]

I was recently testing a refurbished SB-200 I am working on. I am using my
K2 as the exciter, and had issues on all bands with the K2 remember the
power output
requested. I have connected everthing as follows: K2/100>>MFJ-993 Tuner in
bypass to only show power in and SWR on input circuit of amp,
>>SB-200>>LP-100 wattmeter>>1KW dummy load.
 
When I would advance power output from about 10W or so to 70-90W output in
to amp, when I take the K2 out of tune mode, and re-enter, the power would
be 20W or so until I moved the Power knob a bit, then it would go back to
the 70-90W requested. The K2 and the amp are about a foot apart, but the
cover is off the amp, since I was doing some input circuit adjustments.
Maybe I am getting RF back in to the K2?
 
 

 

Mike Short

AI4NS

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[Don Wilhelm-4]

Mike,

Check the KPA100 manual - during TUNE the power is reduced to 20 watts.  
If you need to TUNE at full power, you can either press the TUNE and
DISPLAY buttons together, or rotate the power knob to the power level
desired after the TUNE operation has started.

73,
Don W3FPR

Mike Short wrote:

> I was recently testing a refurbished SB-200 I am working on. I am using my
> K2 as the exciter, and had issues on all bands with the K2 remember the
> power output
> requested. I have connected everthing as follows: K2/100>>MFJ-993 Tuner in
> bypass to only show power in and SWR on input circuit of amp,
>  
>>> SB-200>>LP-100 wattmeter>>1KW dummy load.
>>>      
>  
> When I would advance power output from about 10W or so to 70-90W output in
> to amp, when I take the K2 out of tune mode, and re-enter, the power would
> be 20W or so until I moved the Power knob a bit, then it would go back to
> the 70-90W requested. The K2 and the amp are about a foot apart, but the
> cover is off the amp, since I was doing some input circuit adjustments.
> Maybe I am getting RF back in to the K2?
>  
>  
>
>  
>
> Mike Short
>
> AI4NS
>
> [hidden email]
>
>  
>
> No virus found in this outgoing message.
> Checked by AVG.
> Version: 7.5.524 / Virus Database: 269.24.4/1476 - Release Date: 5/31/2008
> 12:25 PM
>  
> _______________________________________________
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>  

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[Evert Bakker (PA2KW)]

Hello Mike,

I've seen similar behavior on my K2 when using it with a transverter and
power amplifier although it wasn't that bad. I was not able to solve the
problem. I did a lot on earthing, wiring or positioning equipment and
antenna direction, but it was consistent.

I'm almost sure that it is RF detection at the selection diode of the power
potentiometer. Turning the power knob CCW to a certain extend would even
INcrease power!

I'm all ears to hear how you solve this.

73's, Evert PA2KW

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Mike Short
Sent: Monday, June 02, 2008 00:08
To: [hidden email]
Subject: [Elecraft] K2/100 RF output varies

I was recently testing a refurbished SB-200 I am working on. I am using my
K2 as the exciter, and had issues on all bands with the K2 remember the
power output
requested. I have connected everthing as follows: K2/100>>MFJ-993 Tuner in
bypass to only show power in and SWR on input circuit of amp,
>>SB-200>>LP-100 wattmeter>>1KW dummy load.
 
When I would advance power output from about 10W or so to 70-90W output in
to amp, when I take the K2 out of tune mode, and re-enter, the power would
be 20W or so until I moved the Power knob a bit, then it would go back to
the 70-90W requested. The K2 and the amp are about a foot apart, but the
cover is off the amp, since I was doing some input circuit adjustments.
Maybe I am getting RF back in to the K2?
 
 

 

Mike Short

AI4NS

[hidden email]

 

No virus found in this outgoing message.
Checked by AVG.
Version: 7.5.524 / Virus Database: 269.24.4/1476 - Release Date: 5/31/2008
12:25 PM
 
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[Evert Bakker (PA2KW)]

Hi Mike,

Yes I did not read your message carefully enough.
I had a similar problem as I wrote, but that wasn't in the tune mode.
Your problem has been solved easily :-)

I'll try solving my problem again next weekend.

Thanks for e-mail!

73's, Evert PA2KW
 


-----Original Message-----
From: Mike Short [mailto:[hidden email]]
Sent: Monday, June 02, 2008 01:00
To: [hidden email]
Subject: RE: [Elecraft] K2 /100 RF output varies

According to Don, W3FPR:

"Mike,

Check the KPA100 manual - during TUNE the power is reduced to 20 watts.  
If you need to TUNE at full power, you can either press the TUNE and
DISPLAY buttons together, or rotate the power knob to the power level
desired after the TUNE operation has started.

73,
Don W3FPR"


Operator Error on my part,

Mike

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12:25 PM
 


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