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Blown Diodes - K3

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k0wa@swbell.net

Blown Diodes - K3

It looks like D36 and D37 on the SWR Bridge on the K3 RF Board are no longer functioning. Kaput.

Questions:

Where are these diodes located on the board?
Are they Surface Mount? If so, can they be changed to "regular" diodes
What are the parameters of these diodes?
Can I still operate the rig? (KS QSO Party this weekend.) (The SWR on the meter if very good so there is not issue with high swr, just a wrong reading.)
Has anyone changed these out and can give me some instructions?

Here is what I did to determine what is going on....

I have the K3 connected to a dummy load through an external watt meter as well
The watt meter says the SWR is fine on all bands. 100watts forward and no watts back.

The K3 says that it is 2.6 or 3.6 to one on all bands and I am putting out about 25 watts while using the XMIT Key
When I go below 12 watts it seems to be fine, but when I go above 12 watts
the SWR Reading goes up considerably but the external meter stays the same....flat!

This happens on bands 80 through 10 meters. I did not try 160 or 6 meters
I am in bypass mode on the bands mentioned.

Lee Buller - K0WA

===================================================================================

In our day and age it seems that Common Sense is in short supply. If you don't have any Common Sense - get some Common Sense and use it. If you can't find any Common Sense, ask for help from somebody who has some Common Sense. Is Common Sense divine?

Common Sense is the image of the Creator expressing revealed truth in my mind. - John W. (Kansas)

Never interfere with anything that isn't bothering you.
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Don Wilhelm-4

Re: Blown Diodes - K3

Lee,

I don't have the answers to your questions, but ---
Contact Elecraft support and they should be able to lead you through a fix.

73,
Don W3FPR

On 8/20/2013 11:34 AM, Lee Buller wrote:

> It looks like D36 and D37 on the SWR Bridge on the K3 RF Board are no longer functioning. Kaput.
>
> Questions:
>
> Where are these diodes located on the board?
> Are they Surface Mount? If so, can they be changed to "regular" diodes
> What are the parameters of these diodes?
> Can I still operate the rig? (KS QSO Party this weekend.) (The SWR on the meter if very good so there is not issue with high swr, just a wrong reading.)
> Has anyone changed these out and can give me some instructions?
>
> Here is what I did to determine what is going on....
>
> I have the K3 connected to a dummy load through an external watt meter as well
> The watt meter says the SWR is fine on all bands. 100watts forward and no watts back.
>
> The K3 says that it is 2.6 or 3.6 to one on all bands and I am putting out about 25 watts while using the XMIT Key
> When I go below 12 watts it seems to be fine, but when I go above 12 watts
> the SWR Reading goes up considerably but the external meter stays the same....flat!
>
> This happens on bands 80 through 10 meters. I did not try 160 or 6 meters
> I am in bypass mode on the bands mentioned.
>

______________________________________________________________
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

Iain MacDonnell - N6ML-2

Re: Blown Diodes - K3

In reply to this post by k0wa@swbell.net

I had to replace D36 and D37 once. They are surface-mount, but not too
difficult. They're located on the bottom of the main RF board, under
the KAT3/KANT3. Concur with Don on suggestion of engaging support for
advice...

73/GL,

~iain / N6ML

On Tue, Aug 20, 2013 at 8:34 AM, Lee Buller <[hidden email]> wrote:

>
> It looks like D36 and D37 on the SWR Bridge on the K3 RF Board are no longer functioning. Kaput.
>
> Questions:
>
> Where are these diodes located on the board?
> Are they Surface Mount? If so, can they be changed to "regular" diodes
> What are the parameters of these diodes?
> Can I still operate the rig? (KS QSO Party this weekend.) (The SWR on the meter if very good so there is not issue with high swr, just a wrong reading.)
> Has anyone changed these out and can give me some instructions?
>
> Here is what I did to determine what is going on....
>
> I have the K3 connected to a dummy load through an external watt meter as well
> The watt meter says the SWR is fine on all bands. 100watts forward and no watts back.
>
> The K3 says that it is 2.6 or 3.6 to one on all bands and I am putting out about 25 watts while using the XMIT Key
> When I go below 12 watts it seems to be fine, but when I go above 12 watts
> the SWR Reading goes up considerably but the external meter stays the same....flat!
>
> This happens on bands 80 through 10 meters. I did not try 160 or 6 meters
> I am in bypass mode on the bands mentioned.
>
> Lee Buller - K0WA
>
>
>
> ===================================================================================
>
>
> In our day and age it seems that Common Sense is in short supply. If you don't have any Common Sense - get some Common Sense and use it. If you can't find any Common Sense, ask for help from somebody who has some Common Sense. Is Common Sense divine?
>
> Common Sense is the image of the Creator expressing revealed truth in my mind. - John W. (Kansas)
>
> Never interfere with anything that isn't bothering you.
> ______________________________________________________________
> 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