[Elecraft] P3: Vertical Lines for display question

Jim Brown jim at audiosystemsgroup.com
Sat Sep 16 14:40:53 EDT 2017


Hi Dave,

Take a look at the screen grabs in 
http://k9yc.com/P3_Spectrum_Measurements.pdf

These were done two ways. The ones without the SVGA were saved from the 
P3 Utility. Those with the SVGA were saved to a USB thumb drive via the 
SVGA menu.  These data were all obtained by accumulating peaks on the 
signal. Before saving the screens, I used the cursor to points along the 
curve on both sides to document the frequencies and levels and wrote 
them down. Then I saved the screens.

Note also that there are small calibrations along the top of the screen, 
and that these are sub-divisions of the scan width. Using graphics 
editing software, it's possible (not easy) to turn the screen grab 
negative so that the background is white and the traces are some color 
dark enough to print. When using these calibrations, it helps to set the 
scan width to a the smallest value that contains all the data and that 
makes these calibrations a convenient scale. When printing the graphics, 
it helps to scale the image so that the spacing between calibrations is 
the same or close to whatever ruler is available. Also, decimal rulers 
help.

The edited graphics can be printed, vertical lines drawn, and points 
picked off with an architect's or engineer's scale. I've done this with 
some P3 data, and also ARRL Lab data for which data files were not 
available. Older engineers (those of us trained 50 or more years ago) 
learned these techniques (and a lot more) in our freshman year.  Data 
for Fig 2 in k9yc.com/TXNoise.pdf was obtained by applying these methods 
to the plots on Pages 1 and 2.

If this sounds like a lot of work, you're right. Which gives you an idea 
how much time I put into producing those reports. :)

73, Jim K9YC

On 9/16/2017 10:43 AM, Dave Cole wrote:
> I am looking to impress a grid structure on the P3, as opposed to some 
> lines I need to move.  I want to be able to document exactly how wide 
> something is signal wise, by taking a snap of the signal, then looking 
> at it with my computer. 




More information about the Elecraft mailing list