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K3 tuning power question

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Richard Fjeld-2

K3 tuning power question

I want to verify my understanding. In the interest of protecting the output transistor(s) against a mishap in one's antenna system, would it be better to tune at 10 watts (finals off) or at 15 watts (finals on)?

Or is the driver so well protected that it doesn't matter?

Dick, n0ce

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Cady, Fred

Re: K3 tuning power question

Hi Dick,
The K3 uses either 5 or 10 watts to tune the internal KAT3 tuner. Mine uses 5 watts and I'm not sure under what conditions it would use 10 watts. You can see the tuning power used briefly displayed in the VFO B area when you tap the ATU TUNE button.

By the way, the TUN PWR menu doesn't affect the power used when tuning the tuner. It sets the power output when you hold the TUNE button.
Cheers and 73,
Fred KE7X

Author of:
"The Elecraft K3: Design, Configuration and Operation 2nd ed"
"The Elecraft KX3 - Going for the summit"
"The Elecraft KPA500 and KAT500 - the K-Line Dream Station"
Printed, coil bound copies of these are all available at www.elecraft.com
KPA500 and KAT500 Quick Set Up Guide
http://www.ke7x.com/home/k-line-introduction-and-set-up-guide
KAT500 and KXPA500 Tuner Operation
http://www.ke7x.com/home/kat500-and-kxpa100-tuners

> -----Original Message-----
> From: Elecraft [mailto:[hidden email]] On Behalf Of
> Richard Fjeld
> Sent: Saturday, January 17, 2015 8:01 AM
> To: Elecraft
> Subject: [Elecraft] K3 tuning power question
>
> I want to verify my understanding. In the interest of protecting the
> output transistor(s) against a mishap in one's antenna system, would it
> be better to tune at 10 watts (finals off) or at 15 watts (finals on)?
>
> Or is the driver so well protected that it doesn't matter?
>
> Dick, n0ce
>
>
>
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

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Don Wilhelm-4

Re: K3 tuning power question

In reply to this post by Richard Fjeld-2

Dick,

It is easier on the K3 to tune at 15 or 20 watts.
Reason -- at 10 watts, only the low power PA is active and it will be
operating near the upper end of its range.
Increasing the power activates the 100 watt amp and at 15 or 20 watts,
everything is loafing along at much less than its full output.

73,
Don W3FPR

On 1/17/2015 10:00 AM, Richard Fjeld wrote:
> I want to verify my understanding. In the interest of protecting the output transistor(s) against a mishap in one's antenna system, would it be better to tune at 10 watts (finals off) or at 15 watts (finals on)?
>
> Or is the driver so well protected that it doesn't matter?
>
>

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Neil Martinsen-Burrell

Re: K3 tuning power question

Would the same reasoning apply to the K2/100 as well? I have recently
acquired one and would like to take good care of the final transistors
(after a scary experience of trying to test power output while using the
wrong antenna connector). I know that 20W is the default with the tune
button, but one could then adjust it with the power knob.

-Neil N0FN

On Sat, Jan 17, 2015 at 10:06 AM, Don Wilhelm <[hidden email]> wrote:

> Dick,
>
> It is easier on the K3 to tune at 15 or 20 watts.
> Reason -- at 10 watts, only the low power PA is active and it will be
> operating near the upper end of its range.
> Increasing the power activates the 100 watt amp and at 15 or 20 watts,
> everything is loafing along at much less than its full output.
>
> 73,
> Don W3FPR
>
> On 1/17/2015 10:00 AM, Richard Fjeld wrote:
>
>> I want to verify my understanding. In the interest of protecting the
>> output transistor(s) against a mishap in one's antenna system, would it be
>> better to tune at 10 watts (finals off) or at 15 watts (finals on)?
>> Or is the driver so well protected that it doesn't matter?
>>
>>
>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

Don Wilhelm-4

Re: K3 tuning power question

Neil,

Yes, the same thing applies to the K2/100

73,
Don W3FPR

On 1/17/2015 9:41 PM, Neil Martinsen-Burrell wrote:
> Would the same reasoning apply to the K2/100 as well? I have recently
> acquired one and would like to take good care of the final transistors
> (after a scary experience of trying to test power output while using the
> wrong antenna connector). I know that 20W is the default with the tune
> button, but one could then adjust it with the power knob.
>
>

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