And this one too...
At all times, transmitter power must be the minimum necessary to carry out the
desired communications.
> On Oct 30, 2014, at 10:16 AM, Robert Logan via Amps <amps@contesting.com>
> wrote:
>
> Thought I might mention the legal limit for AM is 375 watts carrier. Bob.
> NZ5A
>
> Sent from my iPhone
>
> On Oct 30, 2014, at 9:04 AM, Kimberly Elmore <cw_de_n5op@sbcglobal.net> wrote:
>
> Any amp will be inefficient when used as a linear amplifier for AM because as
> drive is reduced, efficiency is reduced. They will all generate a lot of heat
> in this application. However, the AL-1200 should hold up well to the
> lock-and-talk culture. In AM, PEP is 4X the carrier, Overall, you want the
> carrier to be at 1/4 of the amp's rated PEP output.
>
> Assuming the driver generates 100 W output, tune the amp for max or 1500 W
> output (whichever comes first) with the amp in SSB mode. You want SSB mode
> because you want the best linearity. Whether or not you use SSB or CW makes
> little difference in the efficiency for your application but makes a big
> difference in linearity.
>
> Usually, when the driving rig is in AM mode, the carrier is reduced to 1/4 of
> the max PEP SSB output. In such cases, you should see no more than 375 W
> carrier power (375 x 4 = 1500).
>
> If you are trying to drive it with an older plate-modulated tube rig, you ill
> have to be careful if you reduce the power output because the modulation
> transformer is designed with a particular output impedance in mind. If you
> reduce the drive to the PA, the impedance changes and you will have to set
> the proper audio level using a scope or modulation monitor.Start with audio
> gain at zero, bringing it up slowly. Otherwise, you risk arcing in and
> destruction of the modulation transformer.
>
> Kim N5OP
>
>
> On Thursday, October 30, 2014 8:05 AM, Gary Smith <Gary@ka1j.com> wrote:
>
>
>
> One thing for sure, run it at the CW
> setting, use the lower KV setting and you
> will run far cooler for a given KW out.
>
> 73,
> Gary
> KA1J
>
>
>> I want to run my AL-1200 on AM for a short stint (2 hours operating
>> time, 50% overall duty cycle). I have tested it at about 225 watts
>> carrier output, and with moderately high duty cycle transmissions (known
>> in the AM crowd as 'Old Buzzarding'), it gets quite hot.
>>
>> What is the max recommended AM carrier power for long-winded transmissions?
>>
>> Also, I'm assuming it should be tuned up for proper operation at double
>> the carrier power.
>>
>> I searched the list finding no real answers.
>>
>> Thanks,
>>
>> Tony, K1KP
>
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