[Elecraft] K2 in Overdrive Mode: 20 watts ?

Mon Apr 22 18:19:00 2002

Hi Don,

Your points are well taken and it's difficult to disagree that the difference between 14 watts and 20 watts is less than 1 S unit and yes it may only be a psychological increase in signal strength. (What would Dr. Freud say if he owned a K2?)

On the other hand part of the beauty of the K2 is that it lends itself to experimentation. It seems like it's a question of heat dissipation and if the rig was designed close to the edge or not. It may (or not not) work OK.

Glad that I could stir up a little controversy! 
Has anyone actually tried this??? Anyone getting 20 watts out?

Tnx again and 73,
Jim, WA2UMP

In a message dated Mon, 22 Apr 2002 �5:49:33 PM Eastern Daylight Time, "Don Brown" <[email protected]> writes:

>Hi
>
>The question is not if the K2 will output 20 watts it's why would you want to push the radio beyond the design limits. If you are trying to drive a power amp where the extra 5 watts might be amplified 10 to 20 times then you might want to consider it if it could be done safely and without generating splatter all up and down the band. However if you are just trying to get 20 watts so you can say you are running 20 watts, the difference will not even be noticeable. It would take an increase from 15 to 60 watts to even make 1 S unit and you can't push it that far. The 2SC1969 finals are rated 20 watts dissipation at 60 volts at 6 amps not 16 volts as you stated in your post. The finals could stand a higher supply voltage but that supply voltage is running a lot of other things in the radio. Increasing the voltage will upset the biasing of the driver and cause the voltage regulators to dissipate more power possibly overheating them. If you were to push the K2 to 20 watts it would be interesting to look at the output on a spectrum analyzer to see how clean the output really is. I haven't done any of this nor would I want to I can wait for the KPA100 where there will be a real measurable difference and a good Elecraft quality signal. JMHO :-)
>
>Don Brown
>KD5NDB
>
>4 - K2's
>3 - K1's
>All K options
>
>
>----- Original Message -----
>From: [email protected]
>Sent: Monday, April 22, 2002 3:10 PM
>To: [email protected]
>Subject: [Elecraft] K2 in Overdrive Mode: 20 watts ?
>
>It is my understanding that the K2 is capable of about 20 watts output on the lower bands if the power supply is run at 15 volts and the high voltage output protection
>circuit is defeated.
>
>Is anyone getting 20+ watts in this "over-drive" mode?
>
>I realized that this is pushing the rig to the max but I enjoy "life in the fast lane".
>
>If you're getting the 20 watts please share your experience.
>- What power supply are you using and how much current does it pull?
>- How hot does the final and drive get during transmission?
>- Any problems?
>
>73,
>Jim Miller, WA2UMP
>
>
>
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