Looking for some more "Punch" on SSB and No Hi Cur on 30 M

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Looking for some more "Punch" on SSB and No Hi Cur on 30 M

Gottlieb, Jonathan
I've got k2/100 #4856.  I've done the C80, C81 mod.  Everything checks out great, except I still get Hi Cur on 30 M and it doesn't seem very robust on 20 or 17 SSB.  80 and 40 M SSB output is fantastic, often peaking right at 100 watts.  I get 100 W in CW key down on all bands except for 30 M where I get the Hi Cur display.  Any thoughts or ideas on how to fix the Hi Cur on 30 and the less than robust SSB output on 20 and 17?
 
Jonathan Gottlieb
WA3WDK
 
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Re: Looking for some more "Punch" on SSB and No Hi Cur on 30 M

Vic K2VCO
Gottlieb, Jonathan wrote:
> I've got k2/100 #4856.  I've done the C80, C81 mod.  Everything
> checks out great, except I still get Hi Cur on 30 M and it doesn't
> seem very robust on 20 or 17 SSB.  80 and 40 M SSB output is
> fantastic, often peaking right at 100 watts.  I get 100 W in CW key
> down on all bands except for 30 M where I get the Hi Cur display.
> Any thoughts or ideas on how to fix the Hi Cur on 30 and the less
> than robust SSB output on 20 and 17?

If you get 10 watts output when the K2 is in QRP mode with a reasonable
current draw (less than 3 amps), then you might have resistors at R80-81
in the KPA100 that are too inductive.  In a private email, I was told by
one person who had a similar problem that he got good results by
replacing these resistors with Vishay BC 1.6 ohm, 2W, 5%, metal film
resistors (Mouser Cat No. 594-5083NW1R600J; Vishay P/N
5093NW1R600J12AFX) that are known to have lower inductance.  I haven't
tried this personally.  I suggest corresponding with Gary at Elecraft
about your problem.

--
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco
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Re: Looking for some more "Punch" on SSB and No Hi Cur on 30 M

Vic K2VCO
In reply to this post by Gottlieb, Jonathan
Aaargh, I meant R19/R20, not 80/81.

Gottlieb, Jonathan wrote:
> I've got k2/100 #4856.  I've done the C80, C81 mod.  Everything
> checks out great, except I still get Hi Cur on 30 M and it doesn't
> seem very robust on 20 or 17 SSB.  80 and 40 M SSB output is
> fantastic, often peaking right at 100 watts.  I get 100 W in CW key
> down on all bands except for 30 M where I get the Hi Cur display.
> Any thoughts or ideas on how to fix the Hi Cur on 30 and the less
> than robust SSB output on 20 and 17?

If you get 10 watts output when the K2 is in QRP mode with a reasonable
current draw (less than 3 amps), then you might have resistors at R80-81
in the KPA100 that are too inductive.  In a private email, I was told by
one person who had a similar problem that he got good results by
replacing these resistors with Vishay BC 1.6 ohm, 2W, 5%, metal film
resistors (Mouser Cat No. 594-5083NW1R600J; Vishay P/N
5093NW1R600J12AFX) that are known to have lower inductance.  I haven't
tried this personally.  I suggest corresponding with Gary at Elecraft
about your problem.

--
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco
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