[Elecraft] Running high power

[Bob McGraw]

In running my KPA500/KAT500 combo I found no issues with any RFI of any 
type.

Now what I did find, if I hit it too hard, it would flat top and 
generate all sorts of crap.  This sould get into the computer and lock 
up WSJT-x.  Also It would turn on or turn off one of the TVs on 
satellite service.   And the satellite receiver would change channels. 
(That really annoyed the XYL)

I find the amp to be very clean up to a point.  Exceed that point, even 
the slightest amount, and it turns into a quasi square wave generator.  
No amount of filtering I tried would remedy the issue. The only solution 
is to set the drive power to attain 500 watts or less as measured on a 
reliable power meter.  Then don't let the exciter exceed that drive 
level.  I then set the PWR CAL via the amp menu for the correct value.  
This must be done on each band using a known good dummy load.

I used my K3S to drive the amp and had the PWR SET PER BND active.   The 
amp does require slightly different drive power amounts on different 
bands.   I also set my TUNE PWR in the radio for 20 watts.   This would 
always drive the amp to near rated output.

The station antennas, the coax center fed 80/40M has a 1:1 balun at the 
feed-point, the 160M 1/2 wave wire is center fed with balanced line and 
a custom hybrid balun at the operating desk. Each piece of station 
equipment is bonded by a dedicated conductor to the station power supply 
ground terminal.    Being on the 2nd floor of the house, I do not use 
any external station ground. Lightning protection is accomplished 
outside of the house.

Hope this helps.

73

Bob, K4TAX

On 11/23/2022 9:58 AM, elecraft-request at mailman.qth.net wrote:
> Message: 13
> Date: Tue, 22 Nov 2022 22:36:46 +0000 (UTC)
> From: Al Lorona<alorona at sbcglobal.net>
> To: Elecraft Reflector<elecraft at mailman.qth.net>
> Subject: [Elecraft] Running high power
> Message-ID:<1647168817.1936686.1669156606886 at mail.yahoo.com>
> Content-Type: text/plain; charset=UTF-8
>
> I'm really curious to ask those on this list who run high power:
>
> Do you find that you get into all kinds of devices around the house?
>
> I ran the KPA-500 in an extended manner for really the first time during the Phone SS and immediately:
>
> 1/ interfered with FM broadcast radio.
>
> 2/ caused the internet to drop out every time I keyed up on the lower bands.
>
> Am I the only one? Those of you who run high power all the time... how do you deal with these annoyances?
>
> Al? W6LX/4
>