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KPA 500 - Can you use it on AM?

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KPA 500 - Can you use it on AM?

I know the KPA 500 is designed for SSB and CW, but I have always wondered if you can use a KPA500 on AM and, if so, what would be the maximum wattage you should use? The manual
doesn’t say anything about it. 73 Mike KF6KXG
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Grant Youngman-2

Re: KPA 500 - Can you use it on AM?

No reason why not. If it were me, I’d keep the unmodulated carrier out to around 90-100 W to allow for some headroom. There’s no reason to push it past that.

Grant NQ5T
K3 #2091 KX3 #8342

> On Feb 27, 2019, at 9:20 PM, Mike Lichtman via Elecraft <[hidden email]> wrote:
>
> I know the KPA 500 is designed for SSB and CW, but I have always wondered if you can use a KPA500 on AM and, if so, what would be the maximum wattage you should use? The manual
> doesn’t say anything about it. 73 Mike KF6KXG
> ______________________________________________________________
> 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

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Don Wilhelm

Re: KPA 500 - Can you use it on AM?

In reply to this post by Elecraft mailing list

Mike,

You can use the KPA500 on AM at the full 500 watt rating.
BUT remember that the power is Peak to Peak.
So you will not get 500 watts of carrier and a total of 500 watts of
sideband energy. You will get 250 watts of carrier and 125 watts of
sideband energy in each sideband - for a total of 500 watts PEP.

If you are long-winded on AM, you should reduce the power - check the
temperature.

73,
Don W3FPR

On 2/27/2019 9:20 PM, Mike Lichtman via Elecraft wrote:

> I know the KPA 500 is designed for SSB and CW, but I have always wondered if you can use a KPA500 on AM and, if so, what would be the maximum wattage you should use? The manual
> doesn’t say anything about it. 73 Mike KF6KXG
> ______________________________________________________________
> 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
>

Alan Bloom-2

Re: KPA 500 - Can you use it on AM?

In reply to this post by Elecraft mailing list

The peak of a 100%-modulated AM signal is twice the amplitude of the
unmodulated carrier, or 4 times the power. So the keep the peak power
below 500W, the carrier power should be no more than 500/4 = 125 watts.

You might need to keep it somewhat below that if you make long
transmissions.

Just as a point of interest, with sine-wave audio at 100% modulation,
each sideband has 1/4 the carrier power, so even though the peak power
is 4x the carrier, the total *average* RF power is only 1.5x.

Alan N1AL

On 2/27/19 6:20 PM, Mike Lichtman via Elecraft wrote: