[Elecraft] KPA500 questions

[Fred Jensen]

On 11/14/2011 1:15 PM, Sebastian, W4AS wrote:

> What have you found to be the actual output power, on a dummy load
> using a good power meter other than the internal one.

Same as what the LED's say when the highest one just comes on.
>
> Is the maximum output the same on all modes (CW/AM/FM etc.)?

Yes, don't know about FM, never used it but it sounds like RTTY, see 
below.  AM will have 50% of the power in the "carrier" [which "carries" 
nothing], and 25% in each of the two identical sidebands.  PEP will be 500W.
>
> Is the maximum output the same on all bands (what happens on 30
> meters)?

It will allow you to operate illegal if you choose [200W max on 30m]
>
> In the event of a high SWR, does the output begin to drop
> progressively, and/or does it just stop at some point?

It runs fine for me at about 2:1, then it trips off.

   What is the
> typical SWR that will keep it happy at full output (without getting
> into a discussion of resonance and actual power out the antenna)?

2:1
>
> Finally, I read about the duty cycle of 10 minutes on and 5 minutes
> off, and I still wonder how it would keep it up with modes such as
> WSJT, where there is typically 30 seconds on and 30 seconds off?

Don't do WSJT but I'm sure just fine.  I have run it @500W in RTTY 
contests and watch the PA Temp.  It rises, the fans come on, it goes 
back down.  Does this all day, as long as I can keep my butt in the chair.

I thought WSJT was a low power mode.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2012 Cal QSO Party 6-7 Oct 2012
- www.cqp.org