New SDRPlay SAS Spectrum analyzer - Page 1
Forum section: electronics / rf-microwave

author: Beamin
author_rank: Super Contributor
timestamp: October 11, 2018, 08:41:40 am
content: https://www.sdrplay.com/downloads/Does this replace a real spectrum analyzer? If so that would be awesome I have never used one but always wanted one. Or is this more like a toy that needs hardware to be a real spectrum analyzer? Looks like a real one as far as "buttons" go...

author: 9aplus
author_rank: Regular Contributor
timestamp: October 11, 2018, 10:39:02 am
content: From the first hand experience, it is good enough for "fair preview"...in case that you do not need accurate +/- 5 dB calibration.My "lab" includes Agilent E7495B test set, but most of the time have RSP1 with meThis is the last use:https://discourse.myriadrf.org/t/ground-control-to-major-tom/3371

author: Beamin
author_rank: Super Contributor
timestamp: October 11, 2018, 11:23:43 am
content: Quote from: 9aplus on October 11, 2018, 10:39:02 am+/- 5 db is actually a lot isn't it? What's the sensitivity of a real spectrum analyzer? Are you saying good for qualitative but not quantitative? Playing with the program briefly seemed like it just like using the FFT waterfall in the SDRUno program. One curious thing is it has setting for an Arduino. Does the Arduino act as a trigger like in a scope? How do you physically get the Arduino to interface with it?A while ago I was playing with RF oscillators and to test since I didn't have a scope I put the SDR antenna by my circuit. I realized without a crystal its almost impossible to make a stable oscillator and it drifts like crazy and walking around the room shifted it by 5-20 MHZ or touching it would stop the oscillator, a very high precision device that makes a spark gap transmitter seem high tech. If you are using a transistor to make one with no crystal what causes the drift? I thought it was temp at first but the drift would go up and down and had a very broad sloppy 1 MHz wide signal. Be good at jamming things if you could amplify it. Imagine if we tried to send all the data we do today with spark gap transmitters? As a kid I built them and wasn't allowed to play with it when people were watching TV. On a related question I had a cobra CB radio that I turned up the bias current and modulation all the way, then connected it to a really big 1/2 wave of full wave dipole. What was strange was you could make out what I was saying on the cable TV. How can AM be heard over FM receivers? Does the signal get into the IF stage in the TV past where the FM has demodulated? That CB in combination of living on a hill that over looked the city meant I could over key almost all the people in my town up to three towns over. This was before CB was all 100 watt hacked Chinese ham radios where people talked in that strange hill billy accent where they repeat words over and over. Whats your twe twe twe twenty you Fa fa fa faggot mother fu fu fucker 10-4. Now I don't even hear anyone on 11 me me me meters. I see CB's making a come back so people don't have to make local long distance calls. Ahh seven digit dialing so simple.

author: 9aplus
author_rank: Regular Contributor
timestamp: October 11, 2018, 01:44:31 pm
content: Communication with Arduino in function of track gen goes over usb port emulating com portRegarding calibration and normalization of this version of SA SW for SDRPlay please see attachedpicture swap of fix gain for Play RSP1 and Lime SDR LNAL modified for HFSwap goes from 0.5 to 7.6 MHzYou can see that RSP can be only indicative in region arround 1 MHz and bellow and above curveis almost flat / nice for SA applications