Spectrum Analyzer recommendation needed: used, cheap & low frequency measurement - Page 1
Forum section: electronics / projects

author: Hgspine
author_rank: Contributor
timestamp: September 14, 2019, 08:06:44 pm
content: Hello,I am looking to spend $500 USD or below. I only need it to look at jitter in a 50Hz square wave for this project. It can be used, old school, from ebay, but I just want the best one for this purpose in my price range. I see so many models from HP on eBay. Not sure what to get. Also, do I need one with an extended memory option?Thank you.

author: awallin
author_rank: Frequent Contributor
timestamp: September 15, 2019, 06:56:28 am
content: Quote from: Hgspine on September 14, 2019, 08:06:44 pm50Hz and harmonics can be recorded with a sound-card? FFT on the computer gives you the spectrum, and other calculations jitter.sound blaster x-fi or similar?the QA product might have all the software ready for youhttps://quantasylum.com/products/qa401-audio-analyzer

author: 0culus
author_rank: Super Contributor
timestamp: September 15, 2019, 03:33:52 pm
content: You definitely want an audio analyzer and not a spectrum analyzer. Most spectrum analyzers won't even be able to show the fundamental with any kind of guaranteed performance at 50 Hz.

author: Hgspine
author_rank: Contributor
timestamp: September 15, 2019, 09:39:48 pm
content: I prefer a freestanding piece of equipment that does not require a sound card or computer.Ideally I connect it to the testpoint with the 50Kz square wave and it gives me a numeric readout of jitter.

author: 0culus
author_rank: Super Contributor
timestamp: September 15, 2019, 09:45:33 pm
content: Here's an old thread from 2015 from this site.HP/Agilent made a range of instruments that were badged "Dynamic Signal Analyzers" that may suit your needs. You'll have to read up on the datasheets...I'm sure Keysight still has something, but that's going to cost a lot of kilobucks.

author: Smoky
author_rank: Frequent Contributor
timestamp: September 16, 2019, 04:03:40 am
content: Last year I bought an HP 35660A DSA for ~$200 from a company clearing out their unused gear, and just before that time, I recapped my Tektronix TDS420 oscilloscope that I noticed had the FFT option installed. I really didn't know what FFT was, but with the help of the HP 35660A and my new SDG-1032X Waveform generator, I was able to understand what I was seeing on the TDS420 with the "math" function enabled. Even the amplitude results between these "older" machines were extremely close to each other.Here's a link to the thread I started on another website showing screen shots of the DSA compared to what information I seen on the oscilloscope. I'm sure it can do far more than what I'm using it for:https://www.antiqueradios.com/forums/viewtopic.php?f=8&t=359003&hilit=tds420+meets+dsa

author: graybeard
author_rank: Frequent Contributor
timestamp: September 16, 2019, 06:04:34 pm
content: The best low frequency spectrum analyzer isSpectrum Lab. If is free! However it is no longer compatible with modern versions of Windows. I run it usingWineonMint Linux. I runMint Linuxon most of my systems except for the few programs I have that only run under windows.