Power variation

[Dr. William J. Schmidt, II]

Well I have something odd going on. I was trying some new antenna tunings
today and noticed that the power out on the KPA500 would start at about 100
watts.ramp up to 500+ watts over about 10 seconds, and then drop back to 100
watts again.  It kept repeating this cycle as I was talking to someone on
SSB.  The SWR was perfect to the antenna the whole time (external
measurement).  It almost looked like the ALC was oscillating at a very slow
rate (10 seconds or more).  I have not dug into this yet but wonder if
anyone else has seen this?  Checked all the coax connectors already.

 

 

Dr. William J. Schmidt - K9HZ / J68HZ/ 8P6HK/ ZF2HZ/ PJ4HZ

Owner - Operator

Big Signal Ranch

Staunton, Illinois

email:   <mailto:[hidden email]> [hidden email]

 

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[Jack Brindle-2]

Check the transceiver. The KPA has constant gain, and nothing that allows it to change power as you describe.
If you use a K3, then reconsider your choice to use ALC. It is not recommended, nor is it needed with the KPA500. You also might consider recalibrating the transceiver to eliminate that as a culprit in this situation.

If the problem persists, contact customer support.

73,

Jack B, W6FB

Sent from my iPad

> On Apr 27, 2014, at 4:04 PM, "Dr. William J. Schmidt, II" <[hidden email]> wrote:
>
> Well I have something odd going on. I was trying some new antenna tunings
> today and noticed that the power out on the KPA500 would start at about 100
> watts.ramp up to 500+ watts over about 10 seconds, and then drop back to 100
> watts again.  It kept repeating this cycle as I was talking to someone on
> SSB.  The SWR was perfect to the antenna the whole time (external
> measurement).  It almost looked like the ALC was oscillating at a very slow
> rate (10 seconds or more).  I have not dug into this yet but wonder if
> anyone else has seen this?  Checked all the coax connectors already.
>
>
>
>
>
> Dr. William J. Schmidt - K9HZ / J68HZ/ 8P6HK/ ZF2HZ/ PJ4HZ
>
> Owner - Operator
>
> Big Signal Ranch
>
> Staunton, Illinois
>
> email:   <mailto:[hidden email]> [hidden email]
>
>
>
> ______________________________________________________________
> 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]

______________________________________________________________
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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
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