[Elecraft] Blown fuse KPA100

[Don Wilhelm]

Hank,

First thing is an instruction that you apparently skipped - put the K2 
into CW TEST mode before doing that test.  You may have another problem, 
but the amp should not draw significant current in CW TEST.

Second thing (but check it first) is the KPA100 bias.  Be certain the 
bias pot is set fully counter-clockwise until you get to the step for 
adjusting that pot.

You do have a 0.22 uF cap at C31 do you not?

73,
Don W3FPR

Hank Kryger wrote:
> Hi to the group
> 
> I am in the final phases of finishing my KPA100, version "C" with 
> upgrade kit for "D".version.  Manual page 46 (version  C manual)  
> External Amplifier Keying Test (PA KEY),
> 
>  right hand column, step 2,  "measure ground to Q9  tab.  Result  as 
> noted in the manual.
> 
> right hand column step 3, Hold TUNE.  When I do this the DMM reads 3.2 
> Ohm, as noted in the manual, but as soon as the reading starts, when 
> holding TUNE, the Ohm reading starts to increase, at a steady pace.  At 
> around 8.9 or 9.2 Ohm the fuse in my power supply, 20 Amps,  went, 
> replaced it with a 25 Amps, did test again and this time the 20 Amp fuse 
> in the power cord went,
> 
> There was no smoke or smell at the time this happened.   I did have my 
> 50 Ohms dummy Load attached to the antenna as a precaution.
> 
> Any help would be appreciated.  Thanks, Hank WA9QJH