Elecraft

K3 AM Low Power

Classic

List

Threaded

4 messages Options

Stewart@twinwood

K3 AM Low Power

Today I needed to use my K3/100 on AM. I found that the maximum power it would
deliver was about 5W. When the PA stage switches in it seems to make no
difference to the output.

All other modes give the correct output. I have run the TX gain cals OK.

I have the 13kHz FM filter in FL1 on TX which I understand was allowed to be
used for AM TX starting in F/W V4.54.

Anything I have forgotten to switch on or adjust ?

73
Stewart G3RXQ
______________________________________________________________
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

Michael Eberle

Re: K3 AM Low Power

The first thing I would do is load up the K3 Configuration Utility and
connect to the K3. Click on the 'Configuration' tab and select
'Configure Crystal Filters.' Make sure AM enable as well as TX enable
are both selected for FL1.

On 6/1/2013 3:02 AM, Stewart wrote:

> Today I needed to use my K3/100 on AM. I found that the maximum power it would
> deliver was about 5W. When the PA stage switches in it seems to make no
> difference to the output.
>
> All other modes give the correct output. I have run the TX gain cals OK.
>
> I have the 13kHz FM filter in FL1 on TX which I understand was allowed to be
> used for AM TX starting in F/W V4.54.
>
> Anything I have forgotten to switch on or adjust ?
>
> 73
> Stewart G3RXQ
> ______________________________________________________________
> 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

Michael Eberle

Re: K3 AM Low Power

Oh and don't forget to apply the changes before exiting the K3 utility.

Mike
KI0HA

On 6/1/2013 4:45 AM, Michael Eberle wrote:

> The first thing I would do is load up the K3 Configuration Utility and
> connect to the K3. Click on the 'Configuration' tab and select
> 'Configure Crystal Filters.' Make sure AM enable as well as TX enable
> are both selected for FL1.
>
> On 6/1/2013 3:02 AM, Stewart wrote:
>> Today I needed to use my K3/100 on AM. I found that the maximum power
>> it would
>> deliver was about 5W. When the PA stage switches in it seems to make no
>> difference to the output.
>>
>> All other modes give the correct output. I have run the TX gain cals OK.
>>
>> I have the 13kHz FM filter in FL1 on TX which I understand was
>> allowed to be
>> used for AM TX starting in F/W V4.54.
>>
>> Anything I have forgotten to switch on or adjust ?
>>
>> 73
>> Stewart G3RXQ
>> ______________________________________________________________
>> 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
>

Stewart@twinwood

Re: K3 AM Low Power

In reply to this post by Michael Eberle

Hi Michael,
Thanks for your post. Nothing to do with my K3 setup.

I have now got to the bottom of it. Nothing wrong, just the way I was seeing
things.

I expected that when I turned the power control up the carrier power would
a) follow immediately
b) be the same value as the control setting.

What Elecraft have done (and it makes sense) is to somehow sample the signal so
that the modulation peaks equal the power set. It takes time for things to
happen.

I have confirmed this by looking at the output power on a scope.

I was getting confused by expecting the power setting to change much quicker as
in all the other modes...

73
Stewart G3RXQ

On Sat, 01 Jun 2013 04:45:08 -0500, Michael Eberle wrote:
> The first thing I would do is load up the K3 Configuration Utility and
> connect to the K3. Click on the 'Configuration' tab and select
> 'Configure Crystal Filters.' Make sure AM enable as well as TX enable
> are both selected for FL1.
>
> On 6/1/2013 3:02 AM, Stewart wrote:
>> Today I needed to use my K3/100 on AM. I found that the maximum power it
would

>> deliver was about 5W. When the PA stage switches in it seems to make no
>> difference to the output.
>>
>> All other modes give the correct output. I have run the TX gain cals OK.
>>
>> I have the 13kHz FM filter in FL1 on TX which I understand was allowed to be
>> used for AM TX starting in F/W V4.54.
>>
>> Anything I have forgotten to switch on or adjust ?
>>
>> 73
>> Stewart G3RXQ
>> ______________________________________________________________
>> 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