Alignment process


Giulio Paris <giulio.paris@...>
 

Hi
there is a video showing the alignment process for QCX?
It is possible to use on oscilloscope for the alignment process?
Thank 
--
IZ0FVD Giulio


Mike Easterbrook
 

I'm now using a scope direct across the af output for all my alignments. Set around the test tone freq. & very easy to adjust vertical gain  as signal peaks or troughs. I found the bar display bouncing around and switching levels a bit disconcerting & found myself turning the pots in the wrong direction. Scope works well for me.


On Mon, 17 Aug 2020, 21:53 Giulio Paris, <giulio.paris@...> wrote:
Hi
there is a video showing the alignment process for QCX?
It is possible to use on oscilloscope for the alignment process?
Thank 
--
IZ0FVD Giulio


Giulio Paris <giulio.paris@...>
 

On Mon, Aug 17, 2020 at 08:50 AM, Mike Easterbrook wrote:
I'm now using a scope direct across the af output for all my alignments. Set around the test tone freq. & very easy to adjust vertical gain  as signal peaks or troughs. I found the bar display bouncing around and switching levels a bit disconcerting & found myself turning the pots in the wrong direction. Scope works well for me.
I have put my oscilloscope X1 on the output terminal and this is what I see compared to what thw QCX scree shows. Moving the C1 I got the max.
Is this correct?


Mike Easterbrook
 

Yes that's correct - for C1 (8.7) adjust for max amplitude decreasing vertical  gain as necessary to keep within screen. For R17 (8.8), R24 (8.9),  R27 (8.10) adjust for minimum amplitude increasing vertical gain &/or volume pot as display flattens but avoid overloading i.e. maintain sine wave. Try for as close to flatline as possible.
Hope that helps


Curt wb8yyy
 

Giulio

The builtin test circuit for receive alignment is amazing, don't deprive yourself its enjoyment. The only caution is watching it rescale the lcd display, but it shows a different numeric level. Its amazing to use.

Curt wb8yyy


Brent DeWitt
 

I agree with Curt that the built-in bar graph works very well, but the auto-scaling can be a bit distracting.  as an alternative, I've found that simply listening with a decent pair of headphones allows me to null the adjustments pretty well.
-- 
73,
Brent DeWitt, AB1LF
Milford, MA