[Elecraft] K2/100 - Hi Curr and loss of power control - help! de VK7JB

[Mark Bayern]

> Could I have somehow fried D16 & D17 in the KPA100?  I checked these diodes
> in-circuit with my multimeter "diode test" function and there is no voltage
> drop across either.  Does this mean they've both failed open?

No voltage drop across a diode should mean it failed shorted. However,
I would be leery of the in-circuit measurement. Why not lift one end
of each diode so you can be positive that there is nothing besides the
diode in the measurement?

Mark  AD5SS



On Fri, Jun 17, 2011 at 12:59 AM, VK7JB <zendoc at netspace.net.au> wrote:
> Hi Group,
>
> Using my K2/100 #6998 on 20m SSB phone today, running it into an
> experimental small loop antenna.  SWR was 1.5:1.   Then:
>
> Hi Curr warning on LCD - shows continuously in TX.
> Maximum power out (>100W) independent of power control setting
> LED Bargraph stopped displaying RF output (ie no bars lit) despite > 100W
> output measured on external power meter.
>
> Disconnected antenna and attached dummy load - same symptoms.
>
> Could I have somehow fried D16 & D17 in the KPA100?  I checked these diodes
> in-circuit with my multimeter "diode test" function and there is no voltage
> drop across either.  Does this mean they've both failed open?
>
> Is there anything else I should check/look for/measure before I dismantle
> the KPA100 and replace D16 and 17?
>
> Any advice appreciated as always,
>
> 73,
> John
> VK7JB
>