[DSP-10] CW transmit has a raspy sound

[Bob Larkin]

Hi Lee,

I agree, something is quite wrong!!

I dropped a loop near the 127 MHz Osc ( I moved up to get roughly the 
tuning voltage you have) and snapped a picture of the spectrum analyzer:
http://www.proaxis.com/~boblark/127mz1.jpg

This was done with the BW I had available, 100 Hz, as I don't have 300 
Hz.  But  BW=1 kHz looks clean also. There was nothing to see outside of 2 
kHz/div so I

Maybe loop filter components? Possibly, but not likely the PLL IC.  Maybe 
someone else has ideas.

Also, the spectrum to the right  in the unlocked pix seems strange. How did 
you achieve "unlock?" Maybe this is the residual on the phase detector output.

I will pursue this further, after dinner.

73,.  Bob W7PUA

At 04:43 PM 3/28/2006 -0500, you wrote:
>I have been playing around some with an HP 141T spectrum analyzer I just 
>purchased and have been looking at the local oscillators.  While the 19MHz 
>osc looks fairly clean, the 124MHz osc does not. As a mater of fact, it is 
>pretty bad in my opinion.  I don't know if anyone else has had the 
>opportunity to look at theirs but I've put up a web page on my web site 
>showing what I've found.
>
>When taking the measurements, I've removed the coax jumpers from the 
>outputs of the oscillators and used a pigtail coax with an SMA connector 
>to get the signals to the analyzer.
>
>The URL is http://www.aa1yn.com/dsp-10/spec_ana/ and the images are linked 
>to medium resolution images.
>
>Any thoughts? Any questions? Any ideas?
>
>
>Lee Scott - AA1YN http://www.aa1yn.com
>Home of the VHF & Up Register http://www.aa1yn.com/vhf
>Home of the VHF Talk chatroom http://vhftalk.aa1yn.com
>Hooksett, NH
>FN43gc52
>
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