KPA500 ser. no.1066 factory built, Loose diode 1N5408

[Poul Erik Karlshøj (PKA)-2]

We have found a loose (de-soldered) diode 1N5408 in this factory assembled KPA500.
The diode shows >10Mohm in one direction and 2-3 Mohm (varying) in the other direction (DVM)
Where is this diode located (if there are several, then where?), what is its function and is it replaceable by a skilled tech person?
What could be the reason for the failure - it does not appear to have been over-heated, so desoldering appears not logical.

Is there a diagram of the KPA500 available?

73 from
Steen and Paul
OZ8SW (owner) and OZ4UN

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[Nr4c]

Full schematics on website prob with manuals.

Sent from my iPhone
...nr4c. bill

> On May 12, 2014, at 1:58 PM, Poul Erik Karlshøj (PKA) <[hidden email]> wrote:
>
> We have found a loose (de-soldered) diode 1N5408 in this factory assembled KPA500.
> The diode shows >10Mohm in one direction and 2-3 Mohm (varying) in the other direction (DVM)
> Where is this diode located (if there are several, then where?), what is its function and is it replaceable by a skilled tech person?
> What could be the reason for the failure - it does not appear to have been over-heated, so desoldering appears not logical.
>
> Is there a diagram of the KPA500 available?
>
> 73 from
> Steen and Paul
> OZ8SW (owner) and OZ4UN
>
> ______________________________________________________________
> 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
> Message delivered to [hidden email]

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[Vic Rosenthal]

The diode is probably not defective (although the soldering is). Unless
your DVM measures the forward voltage drop of the diode, resistance
readings in the forward direction are probably unreliable.
I would just resolder it and see if it works!

On 5/12/2014 10:58 AM, Poul Erik Karlshøj (PKA) wrote:

> We have found a loose (de-soldered) diode 1N5408 in this factory
> assembled KPA500. The diode shows >10Mohm in one direction and 2-3
> Mohm (varying) in the other direction (DVM) Where is this diode
> located (if there are several, then where?), what is its function and
> is it replaceable by a skilled tech person? What could be the reason
> for the failure - it does not appear to have been over-heated, so
> desoldering appears not logical.
>
> Is there a diagram of the KPA500 available?
>
> 73 from Steen and Paul OZ8SW (owner) and OZ4UN

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

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