n00b SA recommendo with specific task - Page 1
Forum section: electronics / testgear

author: sailah
author_rank: Contributor
timestamp: December 22, 2019, 11:23:18 am
content: Hi,I am a small manufacturer of IoT devices (LoRaWAN, 915mHz) that needs to pre certify my device for FCC Part 15 compliance. I have a test house lined up but I'd like to do a preflight.I have used a SA all of once in my life, Keysight is a very generous sponsor of our lab. So I did use, and have access to, the N9000B with EMI built in. I also bought a Tescom TEM cell. However describing me as inexperienced would be generous, but I am determined.I am looking at the following:Siglent SSA3021X (or plus) with EMI $1395 (TG standard)https://siglentna.com/spectrum-analyzers/ssa3000x-series-spectrum-analyzers/Rigol RSA3015E-TG- $2000https://www.rigolna.com/promos/Rigol is running an EMI special to include the EMI software and near field probes for an extra $400. With the Siglent I would be paying more and I don't get the probes.What would you spend your money on? I see the Siglent is well reviewed against the older Rigol but haven't seen much on the newer Rigol. Or save my money and just borrow the Keysight?Thanks

author: BillB
author_rank: Unknown
timestamp: December 22, 2019, 05:04:50 pm
content: You have free access to the N9000B. Why would you want to spend any money on anything else at this point? Use the N9000B, learn about SA's in general then you will be able to make a more educated selection in the future (though, again, if you have access to Keysight equipment, why would you by your own!?)I've got a Siglent SSA3021X (hacked up). Today I would spend the extra bucks and get the Plus. But, if I had free access to the N9000B, then ...

author: sailah
author_rank: Contributor
timestamp: December 22, 2019, 05:32:53 pm
content: Its a fair question. The Keysight loaner would be great and free but its only on short term borrow, like a couple weeks. I likely need to be doing more tests on antennas and future revisions over the next 3 months. Hence why i want a longer term solution.Borrowing keysight equipment has also proven to be hazardous to my bank account. I ended up with an N6705C power analyzer and modules for battery drain analysis after borrowing their demo.I think I'd be using one a lot more if i had one to play with and $2k is cheaper than having a test house do this.

author: tautech
author_rank: Super Contributor
timestamp: December 22, 2019, 07:54:23 pm
content: Quote from: sailah on December 22, 2019, 05:32:53 pmSVA series for the additional VNA features for antenna work.They're still a fully featured SA too and do all that the SSA and Plus models can do.The 1.5 GHz SVA1015X with EMI option would fit your current needs perfectly.

author: sailah
author_rank: Contributor
timestamp: December 22, 2019, 08:20:01 pm
content: Quote from: tautech on December 22, 2019, 07:54:23 pmSuper thanks for that, looks like a better option as I have a number of antenna options I'd like to test.I assume I can hook this up to my TEM cell with EMI package and see how I fair against CISPR 16 standards? That's really the most pressing need before I send off for certs. The antenna testing is not critical but I'd like to see how my cheap Ali antennas fair against Linx that I spec for higher end installations.This looks like the SSA3021X plus touch screen in addition to the vector option. Need to learn more about what this (vector) does.Like I said, n00b here.

author: nctnico
author_rank: Super Contributor
timestamp: December 22, 2019, 08:27:16 pm
content: For antenna design you'll want to use a vector network analyser. The 'vector part' can show you the phase of a reflected signal and from that you can read the complex impedance. IOW: knowing the complex impedance of your antenna you can easely calculate the matching network to make the power transfer between your RF chip and antenna as good as possible.

author: tautech
author_rank: Super Contributor
timestamp: December 22, 2019, 08:36:27 pm
content: EMI testing image from the Siglent NA site:https://siglentna.com/spectrum-analyzers/ssa3000x-plus/Enter View MoreThe blue line is CISPR 16-1-1 EMI filter and Quasi-peak Detector , Log scale and Limit lineYou can do a bit of VNA work with an external bridge and an ordinary SA but it won't return the in-depth info like a VNA can.Look up Topics (in my profile) where I have posted for some personal investigations using SVA1015X and SVA1032X of antennas I have and one I built for 500m remote control.https://www.eevblog.com/forum/profile/?area=showposts;sa=topics;u=88225

author: sailah
author_rank: Contributor
timestamp: December 22, 2019, 08:43:33 pm
content: In doing a bit more research on this...It appears the Keysight Fieldfox is capable of this vector antenna stuff. We have a number of those (N9914A) at Greentown Labs for our use. So I may just use the Fieldfox for this limited application and keep the SA to just the basics of running my EMI pre testing.What appealed to me about the Rigol option was that there was a specific EMI bundle including near field probes and EMI with a Real Time SA vs the Siglent was a regular SA. Add the EMI and probes and it's more loot. Of course there are other "options" for gettings the Siglent addons for less...Siglent SSA3021X + EMI + NF probes - $2,600Rigol RSA3015E-TG EMI bundle- $2,400

author: tautech
author_rank: Super Contributor
timestamp: December 22, 2019, 08:51:25 pm
content: Quote from: sailah on December 22, 2019, 08:43:33 pmThat gets you a 3.2 GHz SA.Unfortunately we can't do that with the SVA series but we can with the SSA3kX Plus models.The additional fruits of the Plus models (touch display, mouse and keyboard support and modulation analysis) make selection of the Plus series a no brainer.

author: nctnico
author_rank: Super Contributor
timestamp: December 22, 2019, 09:05:48 pm
content: Near field probes aren't expensive nowadays. I really like this kit ($98 ex. shipping):https://j3.rf-explorer.com/60-rfe/specifications/175-rf-explorer-near-field-antenna-kit

author: sailah
author_rank: Contributor
timestamp: December 22, 2019, 09:29:10 pm
content: Quote from: tautech on December 22, 2019, 08:51:25 pmI think that's the way I'm leaning. In reading that "other thread" it appears that the mods may preclude using the EasySpectrum software as it needs a serial number to lock to it. I need to look more into this. That seems like a very useful tool. I know from using my Keysight N6705C that the Keysight software for datalogging is almost mandatory vs the machine controls.Quote from: nctnico on December 22, 2019, 09:05:48 pmThanks, will order those.

author: tautech
author_rank: Super Contributor
timestamp: December 22, 2019, 10:16:55 pm
content: Quote from: sailah on December 22, 2019, 09:29:10 pmEasySpectrum was a necessity with the older SSA series but the later SVA and now SSA Plus models have an inbuilt webserver.......something else I omitted to mention.Just what would your 'PC connected' requirements be so I can confirm any required capabilities ?

author: sailah
author_rank: Contributor
timestamp: December 23, 2019, 01:59:16 pm
content: Quote from: tautech on December 22, 2019, 10:16:55 pmI don't have an specific requirements, all I know is that using the Keysight machine screen vs one of my 28" 4K screens to zoom around and look at uA current profiles is a def nod to the ease of using a computer and mouse. I never use the screen on my Keysight, all controls can be made remotely. Esp when it comes to manipulating the datalog.So I would prefer to use a computer screen if it's an option but that's not a hard rule. The screen on the Siglent is far larger than my Keysight.I read on the forum that EasySpectrum was helpful for EMI so that's why I don't want to hack and xxxxx my serial number.

author: tautech
author_rank: Super Contributor
timestamp: December 24, 2019, 01:46:24 am
content: Quote from: sailah on December 23, 2019, 01:59:16 pmOK a PC print screen of the SVA webserver.......SVA and SSA Plus models work this way just the same.Just a few seconds to set the units URL and then point your browser to it.Here I'm in EMI mode (doing basically nothing....no input signal) and the EMI limit line edit menu.We can edit limit line amplitudes, point and/or time values.What you don't see is the virtual keyboards that pop up when you touch or mouse select the highlighted menu button.Once done you can save or recall/load your EMI limit settings. (in Next Page)

author: NY2KW
author_rank: Regular Contributor
timestamp: January 27, 2020, 04:10:12 am
content: QuoteWill the webserver allow me control of the VNA mode functions? Easyspectrum does not.Jerry

author: tautech
author_rank: Super Contributor
timestamp: January 27, 2020, 04:32:09 am
content: Quote from: NY2KW on January 27, 2020, 04:10:12 amIn a word; totally !Locally or remote.We had the opportunity to connect to a SVA1015X in Ohio USA from NZ and although there was some latency (peak data use time) controlling it was like it was in the next room.QuoteJust checked out the SVA support SW and it appears there's now a version especially for the SVA's:EasySpectrum for SVA1000X - 1.0.5.0 (Release Date 04.09.19 )https://siglentna.com/service-and-support/firmware-software/spectrum-analyzers/#sva1000x-seriesMust check it out.........Install EasySpectrum - V1.0.6.0 (Release Date 11.25.19 ) instead....newer version.Now for interests sake to check it with my SVA1032X.......nope VNA mode doesn't work !

author: tautech
author_rank: Super Contributor
timestamp: January 27, 2020, 06:09:47 am
content: @ NY2KWAnswers to your other questions here:https://www.eevblog.com/forum/testgear/siglent-sva1015x-1-5ghz-spectrum-vector-network-analyzer-(coming)/msg2889306/#msg2889306