[Elecraft] K3/KPA500 10 meter behavior

[Robert Redmon]

Actually, I think my original message was misleading. The problem is 
really the K3 with which I drive the KPA500, causing the overdrive 
condition. When first transmitting, instead of putting out the set power 
(20 watts), my K3 generates significantly more (60 watts according to 
the display on the KPA500 in standby). My KPA500 only requires about 20 
watts to drive it to 500 watts on 10. Consequently, until the K3 settles 
down (a matter of a second or so), it is overdriving the 
amp...significantly.

73,

Bob K5SM

On 8/8/2011 2:42 PM, Robert Garceau wrote:
> No problem on 10 meters on my #165 KPA500
> W1EQ, Bob
>
>
> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Klaus Koppendorfer
> Sent: Monday, August 08, 2011 2:38 PM
> To: Robert Redmon; elecraft at mailman.qth.net
> Subject: Re: [Elecraft] KPA500 10 meter behavior
>
> yes kpa-500 serial 230 has exactly the same behavior
>
> ________________________________________
> Von: elecraft-bounces at mailman.qth.net
> [elecraft-bounces at mailman.qth.net]" im Auftrag von"Robert Redmon
> [k5sm.bob at gmail.com]
> Gesendet: Montag, 08. August 2011 19:16
> Bis: elecraft at mailman.qth.net
> Betreff: [Elecraft] KPA500 10 meter behavior
>
> I put my KPA500 on 10 today for the first time and noticed a rather
> unexpected behavior. Often, on the first character of transmission, the
> K3 drive power apparently spikes, driving the KPA500 to more than 700
> watts. This seems to stabilize following that first dit or two, but I
> have to reduce drive to below 12 w before that behavior stops. Seems the
> 100 watt module in the K3 is behaving poorly. Anyone else noticed this?
> Doesn't seem to be a problem on other bands. (SWR is 1.3:1).
>
> 73,
>
> Bob K5SM
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