[Elecraft] KPA500 active devices!!

[Eric Swartz - WA6HHQ, Elecraft.]

The fcc requires amplifier gain to be 15 decibels maximum for any amatuer radio amplifier. 

In reality, with negative feedback applied to level PA gain, the required drive to reach 500W is closer to 30 W here.
Eric
_..._


"Joe Subich, W4TV" <lists at subich.com> wrote:

>
>The VRF2933 is rated for 300 Watts each according to the data 
>sheet on the manufacturer's web site (Microsemi) ... That makes 
>their use in a 500 W amplifier reasonable from an IMD perspective. 
>
>The VRF 2933 minimum gain is also 20dB (23 dB typical) so it 
>would appear that the KPA-500 should be capable of clean 
>operation with 5 W of drive (e.g., K3 in low power mode). 
> 
>73, 
>
>   ... Joe, W4TV 
> 
> 
>
>
>> -----Original Message-----
>> From: elecraft-bounces at mailman.qth.net 
>> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Doug 
>> Faunt N6TQS +1-510-655-8604
>> Sent: Saturday, April 17, 2010 6:45 PM
>> To: elecraft at mailman.qth.net
>> Subject: [Elecraft] KPA500 active devices!!
>> 
>> 
>> There are two VRF2933's in push-pull, so they're not 750 
>> watts each, but per pair.  There are only three amps in 
>> existance, and no devices have been destroyed (yet).  Again, 
>> 500 watts is a very conservative rating. It's been key-down 
>> for 10 minutes withy no problems.
>> 
>> 73, doug 
>
>
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