Tracking gen for spectrum analyzer  - Page 1
Forum section: electronics / rf-microwave

author: Jesset1996.5
author_rank: Regular Contributor
timestamp: December 18, 2017, 12:49:06 am
content: Hello, can anyone recommend a budget tracking gen for a hp 8590a analyzer? I'm currently a student studying electronics engineering which is why i am trying to acquire a cheep tracking source rather than purchasing a top of the line tracking source/ the one that goes with it. I'm not familiar with using tracking sources yet so any info such as pro's and cons would be helpful. Thanks!

author: DC1MC
author_rank: Super Contributor
timestamp: December 18, 2017, 08:09:49 pm
content: Quote from: Jesset1996.5 on December 18, 2017, 12:49:06 amDepends of the project and purpose that you have in mind, the rock bottom prices are for the Chinese white noise sources, that can be used for filter bandwidth characterization, even determining the resonance frequency of some LC circuits, and barely for measuring the response of of an amplifier.Of course, the output level and spectral distribution is fully hit and mis, there are better noise sources available, that start to cost more and there are no reasonable priced tracking generators, they are either very good and expensive or useless crap and still expensive.If you're good with the RF work and have/can buy some stuff, I recommend this site video on how to build a bit of a better DIY tracking gen, still not very useful for quantitative measurements but OK for characterization.http://www.kerrywong.com/2016/01/10/building-a-tracking-generator/Good luck,DC1MC

author: ezalys
author_rank: Frequent Contributor
timestamp: December 18, 2017, 09:45:29 pm
content: That generator has a 1st LO out, yeah? That puts out a tone which is offset by 2.05 GHz from the sweep frequency. You therefore need a 2.05 GHz oscillator and a mixer to get you back down to the sweep frequency, and perhaps an amplifier and variable attenuator to vary the level of your TG.You could for instance get one of thesehttps://www.ebay.com/itm/Quantity-1-of-Z-COMM-VCO-2040MHZ-to-2140MHZ-V608ME05-MINI-14H/291298542015?hash=item43d2bf01bf:g:BYkAAOSwYshUaWwwand one of thesehttps://www.ebay.com/itm/Designer-Kit-for-VCO-with-0-5-x0-5-Standard-Package-/150201934851Your SA should also have an internal oscillator out... like a 10 MHz out. You need to lock VCO oscillator to a harmonic of the same reference that the SA uses.

author: xwarp
author_rank: Frequent Contributor
timestamp: December 18, 2017, 10:24:38 pm
content: Quote from: ezalys on December 18, 2017, 09:45:29 pmNo, that DIY TG in the video linked uses the 1st LO from the spec-an. The OP would have to see if his spec-an has a LO output on the rear.

author: rhb
author_rank: Super Contributor
timestamp: December 19, 2017, 01:25:46 am
content: The first LO output of an 8590A is on the front. Don't know if it's standard or an option, but it is shown on many eBay listings.So adding a DIY TG seems pretty straight forward as previously suggested.

author: xwarp
author_rank: Frequent Contributor
timestamp: December 19, 2017, 02:41:54 am
content: The 1st LO output on the front might be standard for some but not others. I have a HP 8591E and it does not have one on the front or the back.