calibrating bfo/dds kx1

[IanMW]

I have a minor query on calibrating the dds on a kx1. I have followed the instruction manual and selected a strong sw am station. After adjusting the bfo to -.07 both sidebands are identical, next I tuned to the frequency the station is transmitted on. Using dds I adjusted one of the sidebands to sound correct at that frequency, it was dds = 10.

Now according to the manual that's it, but when I selected between lsb and usb at that same frequency the sidebands appear different? I would have thought they should be the same.

What did I do wrong, any kx1 dds bfo wizards out there? I'm not sure how the adjustments interact.

73,
Ian MM0GYX
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[Don Wilhelm-4]

Ian,

I suspect that you were depending on your ears when you set the BFO, and
you ended up a bit off.
I use WWV here because they transmit well defined tones - I also use
Spectrogram (you can use just about any audio spectrum analyzer) to
display the tone frequencies so that I can be certain I have tuned them
correctly.

It sounds like you did it right, so go back to the BFO part of the
procedure.  You can either start over with the parameter set to zero, or
you can see how much frequency difference there is with the current
settings and either add or subtract from the current setting.

There is really no interaction, but the BFO setting must be correct
before setting the DDS.

73,
Don W3FPR

On 4/25/2012 5:26 PM, Ian Watson wrote:

> I have a minor query on calibrating the dds on a kx1. I have followed the instruction manual and selected a strong sw am station. After adjusting the bfo to -.07 both sidebands are identical, next I tuned to the frequency the station is transmitted on. Using dds I adjusted one of the sidebands to sound correct at that frequency, it was dds = 10.
>
> Now according to the manual that's it, but when I selected between lsb and usb at that same frequency the sidebands appear different? I would have thought they should be the same.
>
> What did I do wrong, any kx1 dds bfo wizards out there? I'm not sure how the adjustments interact.
>
> 73,
> Ian MM0GYX
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
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> Please help support this email list: http://www.qsl.net/donate.html
>

... [show rest of quote]

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