K2 Problems

[Brent Sutphin WB4X]

I now have the basic K2 working as it should after replacing the TX finial
and bias transistors. Now to move on to the KPA100.

Brent
----- Original Message -----
From: "Brent Sutphin" <[hidden email]>
To: <[hidden email]>
Sent: Thursday, August 23, 2012 9:27 PM
Subject: [Elecraft] K2 Problems

> The symptoms I explained earlier were after an electrical storm
> that also took out my cable modem and wireless router.  The K2 was
> connected
> to its antenna but was turned off at the time.  It also had the KPA100 and
> KAT100 installed.  I decided to remove the KPA100 and KAT100 to see if I
> still had the problem with the basic K2.  I wanted to see if the high
> current warning was
> still there.  The high current warning did not come on but the power
> transistors became very hot very quickly. I was not transmitting. That led
> me to believe
> that the power transistors were defective. There very well could be
> problems
> with the KPA100 as well.  Now I'm not so sure.
>
> Brent
> WB4X
>
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[Don Wilhelm-4]

Brent,

In cases of lightning damage to the KPA100, I normally just replace all
the active devices (transistors, diodes and ICs) on the premise that if
not damaged, they have been stressed and will fail later - I do not
normally replace the KPA100 PA transistors because they are quite
hardy..  The KAT100 does not usually endure damage other than the diodes
in the wattmeter and usually the firmware IC, but you can't take my
"usual" observations to heart with lightning damage. Most anything is
suspect, so check it all out.

Look at the boards - If there is evidence of charring or burning, that
area will have to be cleared of carbon and any damaged PC traces
replaced with wire repairs.

What I am saying is that it is less expensive and easier to assume that
all active devices have been damaged and arbitrarily replace then than
it is to try to debug exactly the failing component and then endure the
frustration of an additional failure a few weeks later when a stressed
component fails.  Replacing all the ICs in the KPA100 and KAT100 is not
really that expensive when compared with the alternative.

73,
Don W3FPR

On 8/29/2012 6:48 PM, Brent Sutphin wrote:

> I now have the basic K2 working as it should after replacing the TX finial
> and bias transistors. Now to move on to the KPA100.
>
> Brent
> ----- Original Message -----
> From: "Brent Sutphin" <[hidden email]>
> To: <[hidden email]>
> Sent: Thursday, August 23, 2012 9:27 PM
> Subject: [Elecraft] K2 Problems
>
>
>> The symptoms I explained earlier were after an electrical storm
>> that also took out my cable modem and wireless router.  The K2 was
>> connected
>> to its antenna but was turned off at the time.  It also had the KPA100 and
>> KAT100 installed.  I decided to remove the KPA100 and KAT100 to see if I
>> still had the problem with the basic K2.  I wanted to see if the high
>> current warning was
>> still there.  The high current warning did not come on but the power
>> transistors became very hot very quickly. I was not transmitting. That led
>> me to believe
>> that the power transistors were defective. There very well could be
>> problems
>> with the KPA100 as well.  Now I'm not so sure.
>>
>> Brent
>> WB4X
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

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