[Elecraft] Advice!

[Joe Subich, W4TV]

Don,

 > AM with its 50% power carrier and sidebands that change in amplitude
 > should present a less harsh situation than RTTY which is 100% duty
 > cycle.

AM carrier power is 25% of PEP (not 50%). The RF voltage and current
are each 50% of peak values which makes power 25% of peak. The US
"legal limit" for AM is 375W carrier (1500/4).  For the KPA-500 this
means 125W (certainly no more than 150W) carrier.

73,

    ... Joe, W4TV


On 7/30/2011 3:24 PM, Don Wilhelm wrote:
> Phil,
>
> AM with its 50% power carrier and sidebands that change in amplitude
> should present a less harsh situation than RTTY which is 100% duty
> cycle.  There have been reports of running RTTY for an extended time
> with no harm.  But the specification says 500 watts with 10 minutes key
> down and 5 minutes standby.  It should do at least that well with AM.
>
> The KPA500 has temperature alarms should it get too hot, so it should
> "take care of itself".
>
> 73,
> Don W3FPR
>
> On 7/30/2011 2:49 PM, Phil LaMarche wrote:
>> When running the KPA500 on AM, it there any time limit before unkeying?
>> While operating, the fan comes on and then it kicks into another speed.
>>
>>
>>
>> Thanks
>>
>>
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