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KAT2 - Problem with power calibration (calp)

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Zac Brown-2

KAT2 - Problem with power calibration (calp)

Fellow K2 builders,

I have completed building the KAT2 autotuner, and have run into a
problem on the power calibration step (calp).

The problem is that (on page 17) when I hit the tune button and run 5.0
watts into the KAT2, I'm only measuring about half that much at the
dummy load. The dummy load I'm using is an Elecraft DL1. When I
measure the voltage at the TP1 and ground test points on the DL1, I'm
only seeing about 8.5 volts. That translates to about 2.9 watts.

If I remove the KAT2 and repeat the test with the DL1 connected to the
K2's stock antenna jack, I measure about 12.2 volts at the DL1's test
points, which is about 5.9 watts.

Thus far, the build has gone smoothly. I have visually inspected
everything on the KAT2 and was quite careful during the build. I had no
problems doing the "bridge null adjustment", and was able to dial in C55
to about 007.

Any ideas?

Thanks,

Zac Brown
K2# 4907
KD5IEF
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Don Wilhelm-3

RE: KAT2 - Problem with power calibration (calp)

Zak,

Have you adjusted the forward power trimmer pot on the KAT2 to match the
power that you measure on the DL1? If not, that is what you must do.

Once you set the fwd pwr pot correctly, the K2 microprocessor should display
the power output properly with a TUNE+DISPLAY operation.

If that does not happen, you should follow the schematic in the KAT2 for the
VRFDET output and trace it back to the control board to see why it is not
showing the correct level.

Another question - do you have the K60XV installed. If you do, change R6 in
the KAT2 to 470 ohms as indicated in the K60XV manual. Without the K60XV,
the 47 ohm value for R6 is OK.

73,
Don W3FPR

> -----Original Message-----
> From: Zac Brown [mailto:[hidden email]]
> Sent: Wednesday, September 27, 2006 7:44 PM
> To: [hidden email]; [hidden email]; [hidden email]
> Subject: KAT2 - Problem with power calibration (calp)
>
>
> Fellow K2 builders,
>
> I have completed building the KAT2 autotuner, and have run into a
> problem on the power calibration step (calp).
>
> The problem is that (on page 17) when I hit the tune button and run 5.0
> watts into the KAT2, I'm only measuring about half that much at the
> dummy load. The dummy load I'm using is an Elecraft DL1. When I
> measure the voltage at the TP1 and ground test points on the DL1, I'm
> only seeing about 8.5 volts. That translates to about 2.9 watts.
>
> If I remove the KAT2 and repeat the test with the DL1 connected to the
> K2's stock antenna jack, I measure about 12.2 volts at the DL1's test
> points, which is about 5.9 watts.
>
> Thus far, the build has gone smoothly. I have visually inspected
> everything on the KAT2 and was quite careful during the build. I had no
> problems doing the "bridge null adjustment", and was able to dial in C55
> to about 007.
>
> Any ideas?
>
> Thanks,
>
> Zac Brown
> K2# 4907
> KD5IEF
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.405 / Virus Database: 268.12.9/457 - Release Date: 9/26/2006
>
>

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
http://mailman.qth.net/mailman/listinfo/elecraft

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Elecraft web page: http://www.elecraft.com

Zac Brown-2

Re: KAT2 - Problem with power calibration (calp)

Don,

I was thought I was adjusting R1, but was actually adjusting R2 :)
Everything is working fine now.

Thanks,

Zac
KD5IEF

Don Wilhelm wrote:

> Zak,
>
> Have you adjusted the forward power trimmer pot on the KAT2 to match the
> power that you measure on the DL1? If not, that is what you must do.
>
> Once you set the fwd pwr pot correctly, the K2 microprocessor should display
> the power output properly with a TUNE+DISPLAY operation.
>
> If that does not happen, you should follow the schematic in the KAT2 for the
> VRFDET output and trace it back to the control board to see why it is not
> showing the correct level.
>
> Another question - do you have the K60XV installed. If you do, change R6 in
> the KAT2 to 470 ohms as indicated in the K60XV manual. Without the K60XV,
> the 47 ohm value for R6 is OK.
>
> 73,
> Don W3FPR
>
>
>> -----Original Message-----
>> From: Zac Brown [mailto:[hidden email]]
>> Sent: Wednesday, September 27, 2006 7:44 PM
>> To: [hidden email]; [hidden email]; [hidden email]
>> Subject: KAT2 - Problem with power calibration (calp)
>>
>>
>> Fellow K2 builders,
>>
>> I have completed building the KAT2 autotuner, and have run into a
>> problem on the power calibration step (calp).
>>
>> The problem is that (on page 17) when I hit the tune button and run 5.0
>> watts into the KAT2, I'm only measuring about half that much at the
>> dummy load. The dummy load I'm using is an Elecraft DL1. When I
>> measure the voltage at the TP1 and ground test points on the DL1, I'm
>> only seeing about 8.5 volts. That translates to about 2.9 watts.
>>
>> If I remove the KAT2 and repeat the test with the DL1 connected to the
>> K2's stock antenna jack, I measure about 12.2 volts at the DL1's test
>> points, which is about 5.9 watts.
>>
>> Thus far, the build has gone smoothly. I have visually inspected
>> everything on the KAT2 and was quite careful during the build. I had no
>> problems doing the "bridge null adjustment", and was able to dial in C55
>> to about 007.
>>
>> Any ideas?
>>
>> Thanks,
>>
>> Zac Brown
>> K2# 4907
>> KD5IEF
>>
>>
>> --
>> No virus found in this incoming message.
>> Checked by AVG Free Edition.
>> Version: 7.1.405 / Virus Database: 268.12.9/457 - Release Date: 9/26/2006
>>
>>
>