[K3] Low output 160/80m

[Allan G Duncan]

I recently acquired a used K3 from a silent key with a large number of
options fitted. I already own another K3.

 

I have stripped it down to be a K3/10 to simplify fault finding. The only
option fitted now is a KXV3 interface. I fitted the bypass link in place of
the KPA3. All tests are done with a high quality 50 ohm load.

 

There is no RF output on 160m and only about 4-6W on 80m (It varies in
level, presumably with ALC action). The other bands are all fine on both RX
and TX. Receive on all bands (including 160/80) measures OK using my XG3 as
a test signal. Using a 50MHz scope around the BPF area does not show and
obvious fault with the K3 in TX mode with a cw carrier. The RF power output
control works as expected on all bands except 160 and 80.

 

The TX Gain calibration routine in the K3 Utility fails immediately as the
first band it tries is 160m.

 

I'd welcome any comments before I start swapping boards between my two K3's

 

73

 

Allan

GM4ZUK

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[Nr4c]

Start with K3_support at Elecraft.

...bill nr4c

Sent from my Verizon Wireless 4G LTE DROID

Allan G Duncan <[hidden email]> wrote:

>I recently acquired a used K3 from a silent key with a large number of
>options fitted. I already own another K3.
>
>
>
>I have stripped it down to be a K3/10 to simplify fault finding. The only
>option fitted now is a KXV3 interface. I fitted the bypass link in place of
>the KPA3. All tests are done with a high quality 50 ohm load.
>
>
>
>There is no RF output on 160m and only about 4-6W on 80m (It varies in
>level, presumably with ALC action). The other bands are all fine on both RX
>and TX. Receive on all bands (including 160/80) measures OK using my XG3 as
>a test signal. Using a 50MHz scope around the BPF area does not show and
>obvious fault with the K3 in TX mode with a cw carrier. The RF power output
>control works as expected on all bands except 160 and 80.
>
>
>
>The TX Gain calibration routine in the K3 Utility fails immediately as the
>first band it tries is 160m.
>
>
>
>I'd welcome any comments before I start swapping boards between my two K3's
>
>
>
>73
>
>
>
>Allan
>
>GM4ZUK
>
>______________________________________________________________
>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