EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: rfscalardna on January 22, 2019, 11:42:38 am
-
Hi, I wishing for one of you to be of assistance. I am looking for a signal generator that:
1) Programmable by C/C++/Python through software. Something like redpitaya
2) Scalar
3) Frequency range of 10,000hz (or lower) to Mhz range
Redpitaya is all I could find but it's not scalar. Anyone?
-
From what deduction does the scalar requirement originate from?
-
I bought the cheapest version of the JDS6600, which goes from almost DC to 15MHz for EUR 60.
It has an USB connector on the back which I have never used.
It's not the best function generator ever, with it's R-2R network the output is quite noisy at low levels, but it delivers an amazing bang for the buck. For low levels you could use an attenuator on the output.
The wallwart delivered with this function generator is crap though, but there is plenty of room inside for a little transformer with low capacitance to Mains and a LM7805.
What does "Scalar" mean in the context of a signal generator?
You may be able to do something usefull with a chip like the MCP4922.
This is a resistor string ladder DAC which can be used in "multiplier mode". This means that it is not referencing from a DC voltage source, but from an externally applied signal and the output is divided by the resistor ladder.
MCP4922 only has a 450kHz bandwidth though, but it should not be difficult to find chips with a higher bandwidht.
-
What does "Scalar" mean in the context of a signal generator?
i guess it means normal signal generator, "NOT" vector on which VSG can provide IQ or phase accurate or defined modulator and SSG dont. when looking at the other thread where users testing the bode plot capability on their not so cheap killer in town scope, i remember in those days i programmed DDS 3x25 AWG to do the same with $400 Rigol DSO up to iirc 25-50MHz.
-
So I typed in:
https://duckduckgo.com/html?q=scalar+signal+generator (https://duckduckgo.com/html?q=scalar+signal+generator)
and found:
http://rheslip.blogspot.com/2015/08/the-simple-scalar-network-analyzer.html (http://rheslip.blogspot.com/2015/08/the-simple-scalar-network-analyzer.html)
Then did a bit more reading:
https://en.wikipedia.org/wiki/Scalar_(mathematics) (https://en.wikipedia.org/wiki/Scalar_(mathematics))
And it all confirms Meatrommer's guess. A scalar is a imple number, and probably amlitude is meant in this context.
That simple-scalar-network-analyzer project does look like a fun project, with impressive properties for such a low budget.
Decent frequency range, complete with Python integration, and draws amplitude plots with TkInter. Looks like exactly what OP whishes for.
Typing this post took more time than finding that project.