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AM power for KPA500

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Stephen Victor

AM power for KPA500

Hi. What carrier power will the KPA500 put out for well modulated AM?

Thanks and 73
Steve WA2DTW
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Guy, K2AV

Re: AM power for KPA500

That will be the same ratio as always, set by physics instead of the
manufacturer: carrier set for one quarter of the PEP rating. That
would be 125 watts carrier for 500 watts PEP.

It always seems to be too small.

In the old days of the Johnson desk kilowatt, that was 1 kW carrier
INPUT, with a usual 700 to 750 watts carrier output. With voice
processing, that was a well modulated 3kW PEP output. There was a
reason those guys always sounded so loud, and for how heavy that rig
was.

My AL1200 needs about 30 watts carrier to transmit the max 375 watts
carrier. Just about what my Ranger will do.

73, Guy

On Thu, Apr 14, 2011 at 10:15 AM, Stephen Victor <[hidden email]> wrote:

> Hi. What carrier power will the KPA500 put out for well modulated AM?
>
>
> Thanks and 73
> Steve WA2DTW
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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Grant Youngman

Re: AM power for KPA500

Sent from my iPhone

On Apr 14, 2011, at 10:41 AM, Guy Olinger K2AV <[hidden email]> wrote:

> That will be the same ratio as always, set by physics instead of the
> manufacturer: carrier set for one quarter of the PEP rating. That
> would be 125 watts carrier for 500 watts PEP.
>
> It always seems to be too small.
>
> In the old days of the Johnson desk kilowatt, that was 1 kW carrier
> INPUT, with a usual 700 to 750 watts carrier output. With voice
> processing, that was a well modulated 3kW PEP output. There was a
> reason those guys always sounded so loud, and for how heavy that rig
> was.
>
> My AL1200 needs about 30 watts carrier to transmit the max 375 watts
> carrier. Just about what my Ranger will do.
>
> 73, Guy
>
>
>
>
>
> On Thu, Apr 14, 2011 at 10:15 AM, Stephen Victor <[hidden email]> wrote:
>> Hi. What carrier power will the KPA500 put out for well modulated AM?
>>
>>
>> Thanks and 73
>> Steve WA2DTW
>> ______________________________________________________________
>> 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
>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
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> Please help support this email list: http://www.qsl.net/donate.html

Grant Youngman

Re: AM power for KPA500

Always helps to include text ... :-)

My Ranger won't quite make 375w carrier. Do I have a problem? ;-)

I think the Elecraft amp will make 150w carrier. Hardly a big difference. But enough for a good time anyway.

Not all Desks or KW-1s or similar transmitters are throttled back. Unless it's to drive a 4CX15000 or something :-$

Sent from my iPhone

On Apr 14, 2011, at 10:45 AM, Grant Youngman <[hidden email]> wrote:

>
>
> Sent from my iPhone
>
> On Apr 14, 2011, at 10:41 AM, Guy Olinger K2AV <[hidden email]> wrote:
>
>> That will be the same ratio as always, set by physics instead of the
>> manufacturer: carrier set for one quarter of the PEP rating. That
>> would be 125 watts carrier for 500 watts PEP.
>>
>> It always seems to be too small.
>>
>> In the old days of the Johnson desk kilowatt, that was 1 kW carrier
>> INPUT, with a usual 700 to 750 watts carrier output. With voice
>> processing, that was a well modulated 3kW PEP output. There was a
>> reason those guys always sounded so loud, and for how heavy that rig
>> was.
>>
>> My AL1200 needs about 30 watts carrier to transmit the max 375 watts
>> carrier. Just about what my Ranger will do.
>>
>> 73, Guy
>>
>>
>>
>>
>>
>> On Thu, Apr 14, 2011 at 10:15 AM, Stephen Victor <[hidden email]> wrote:
>>> Hi. What carrier power will the KPA500 put out for well modulated AM?
>>>
>>>
>>> Thanks and 73
>>> Steve WA2DTW
>>> ______________________________________________________________
>>> 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
>>>
>> ______________________________________________________________
>> 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

Tony Estep

Re: AM power for KPA500

In reply to this post by Guy, K2AV

On Thu, Apr 14, 2011 at 10:41 AM, Guy Olinger K2AV <[hidden email]>wrote:

> ...In the old days...a reason those guys always sounded so loud, and for
> how heavy that rig
> was.
>

Ah yes. The guy who got me into ham radio, Mel W0AJU, had a fantastic
home-brew rig that made a kid's eyes pop out. A pair of huge WW2 surplus
triodes in push-pull, modulated by a pair of 4-250a tetrodes. The whole
thing was in a 7-foot rack, because every part was surplus from the military
or broadcast or (in the case of the power transformer) the local power
company. Altogether, that rack must have weighed 400 pounds. The final
plates glowed a nice yellow-red, and when he talked, the plates in the
modulator amp glowed a bright cherry red in time with the audio. His
home-made 20M yagi (coupled to the final by a swinging link) was turned by a
prop-pitch motor from a B-29 and the direction indicator was a string that
wrapped around the mast and ran into the basement shack via a bunch of
pulleys; it had a stick knotted to it that went up and down as the antenna
turned, and there was a piece of paper stuck to a support column that had
NEWSN written on it in pencil. He was on the DX honor roll as were my other
teen idols, the DX gurus of the local club. In those days it took about 225
or so, I think.

>
>
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Guy, K2AV

Re: AM power for KPA500

In reply to this post by Grant Youngman

My incoming line voltage here is 248v. Also it is a restoration by
W4PNT and has some AM mods in it. And I would not be able to certify
that it wasn't 350. Bird wattmeters really ain't that accurate after
all. :>) DX never know the difference, for sure.

73, Guy.

On Thu, Apr 14, 2011 at 11:53 AM, Grant Youngman <[hidden email]> wrote:

> Always helps to include text ... :-)
>
> My Ranger won't quite make 375w carrier. Do I have a problem? ;-)
>
> I think the Elecraft amp will make 150w carrier. Hardly a big difference. But enough for a good time anyway.
>
> Not all Desks or KW-1s or similar transmitters are throttled back. Unless it's to drive a 4CX15000 or something :-$
>
> Sent from my iPhone
>
> On Apr 14, 2011, at 10:45 AM, Grant Youngman <[hidden email]> wrote:
>
>>
>>
>> Sent from my iPhone
>>
>> On Apr 14, 2011, at 10:41 AM, Guy Olinger K2AV <[hidden email]> wrote:
>>
>>> That will be the same ratio as always, set by physics instead of the
>>> manufacturer: carrier set for one quarter of the PEP rating. That
>>> would be 125 watts carrier for 500 watts PEP.
>>>
>>> It always seems to be too small.
>>>
>>> In the old days of the Johnson desk kilowatt, that was 1 kW carrier
>>> INPUT, with a usual 700 to 750 watts carrier output. With voice
>>> processing, that was a well modulated 3kW PEP output. There was a
>>> reason those guys always sounded so loud, and for how heavy that rig
>>> was.
>>>
>>> My AL1200 needs about 30 watts carrier to transmit the max 375 watts
>>> carrier. Just about what my Ranger will do.
>>>
>>> 73, Guy
>>>
>>>
>>>
>>>
>>>
>>> On Thu, Apr 14, 2011 at 10:15 AM, Stephen Victor <[hidden email]> wrote:
>>>> Hi. What carrier power will the KPA500 put out for well modulated AM?
>>>>
>>>>
>>>> Thanks and 73
>>>> Steve WA2DTW
>>>> ______________________________________________________________
>>>> 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
>>>>
>>> ______________________________________________________________
>>> 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
> ______________________________________________________________
> 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
>