Re: Graphing program & stuff ...


Jerry Haigwood
 

Hi Nick,

    The -64dbm is not bad.  However, I am seeing -73dbm from my prototype.   I actually think it might do a bit better.   The prototype is all boxed up and inside the PHSNA box I used RG174 for the Sig Generator out, Freq Counter out and analog input.  I think it might do just a bit better if I had something that went down that low to sweep.  I am going to be building a crystal filter shortly for a measurement receiver and I should be able to see what my true dynamic range is.  I expect it to be about 65db (-10dbm to -75dbm) which isn’t bad for a low cost SNA.  A good SNA would do in excess of 100db.  However, the PHSNA doesn’t cost $20,000 either! ;-)  Let us know how well you like the graphing program.  I am currently using Excel because that is all I got.

Jerry W5JH

"building something without experimenting is just solder practice"

 

From: PHSNA@... [mailto:PHSNA@...] On Behalf Of kennnick@...
Sent: Wednesday, September 25, 2013 10:02 PM
To: PHSNA@...
Subject: [PHSNA] Graphing program & stuff ...

 

 

While waiting for the AD9850 board, Funduino board and PHSNA board I'm having a little fun with my own similar setup.  I've been plotting homebrew crystal filters, crystals themselves, and a LPF.

 

Also thought I'd look for a freeware graphing program that might be better than Excel in some respects.  I've downloaded Data Master 2003 and my preliminary opinion is  that it has some promise. Got it to graph a .CSV data file that I created.  

 

I had some problems initially with my hardware as my noise floor seemed to be about -50 dBm or so.  By rerouting some cables and so on, I can now get down to about -64 dBm, not bad for most of what I'm doing.

 

73-

 

Nick, WA5BDU

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