[Elecraft] K3: reverse 12 volt supply

[Roger D Johnson]

On 9/14/2015 2:42 PM, Roger D Johnson wrote:
> According to the schematic, there is a shunt diode on the PA board. Hopefully, it
> prevented the full 12 volts from appearing on the circuitry. The smoke probably
> came from the chokes ahead of the diode.
>
> 73, Roger
>
>
> On 9/13/2015 11:09 PM, Don Wilhelm wrote:
>> The base K3 is protected by an in-line diode that will not allow reverse 
>> voltage to flow.
>> The same is not true of the KPA3 where the reduction in voltage would not be 
>> tolerable.
>> The KPA3 is protected by a circuit breaker, but in this case did not trip in 
>> time to prevent damage.
>>
>> 73,
>> Don W3FPR
>>
>>