Choosing "hobbyist grade" spectrum analyzer

[Johnny B Good]

John,

Basically nothing comes with the SAA3021X Plus. It has type N connectors, so you'll need a cal kit of some sort, adapters and cables.

Best,

Normally yes however Telonic does offer that RF adapter kit with them for free and while it's only 70 Pound/Euro value it's enough to get one up and going except for cabling where for a few $ea a selection of SMA cables and a Cal kit completes the basic SVA requirements.

 This is the RF adapter kit that Telonic provide as a free addition:-

 https://www.telonic.co.uk/productdetails_popup.asp?productcode=TBCAAS1

JOOI, here's the description of the SSA3015XPlus :-

https://www.telonic.co.uk/SIGLENT-SSA3015X-PLUS-Spectrum-Analyser-p/ssa3015x-plus.htm

which rather suggests that, unlike the SVA3015X, it is based on the same hardware as the 3021 and 3032 models. If true, this would seem to be the cheapest base jump off point for hacking to the 3032 option level. I also noticed that despite the thumbnail implying otherwise, this also comes supplied with a free TBCAAS1 RF adapter kit.

 Can anyone confirm that this is actually the case rather than an error in the description being offered by Telonic?

John

[Noy]

As far as i know SSA3015X Plus is not the same HW Mike SSA3021X Plus. 1.5GHz is not upgradeable to 2.1/3.2.
Look at the datasheet, different DANL values!
Read the hacking thread. It is not the same. You can hack SSA3015X Plus to SVA1015X probably but i think nobody has done this now.

You should look in the market here . Sighound36 is selling bis less used SVA1015X for 950£. He is also in the UK. Makr him an offer if 1.5GHz is enough for you.

[tautech]

Noy is spot on !

SVA1015X was Siglent's first venture into VNA's and where inside the TG port (Port 1) circuitry, the coupler used for VNA capability had some bottom end limitations which was changed in later models for better low end VNA performance.
Presume SSA3015X and SVA1015X use the same HW however other than identical SA specs cross flashing has yet to be proven.
There is much more to gain with SSA3021X Plus. 

[Noy]

 :rant:Ssa3015X andSVA1015X has also some limitaions in TG and VNA lowest frequency..
Again look inzo the datasheets. If its suitable for you. Write a PN to sighound36.

[Johnny B Good]

@noy
@tautech

 Thanks very much for dispelling the "Myth" being perpetrated by Telonic's confusing description.

 I rather suspected the description's veracity, hence my question. What had raised my suspicions about the SSA3015XPlus's hackability was the lack of any customer feedback on this model (and that of the 3075 for obvious price based reasons) versus the five stars given only to the 3021 model, echoing the situation with the SDS2104XPlus DSO/MSO.

 mawyatt had not only neatly summed up the situation but had proved what I'd  suspected (and hoped) would be possible only in the case of the SSA3021XPlus. Thus armed with this new found knowledge, I rather fancy I'll be placing an order with Telonic in the next few days, depending on whether Labtronix had merely forgotten to mention their free TBCAAS1 or equivalent and whether I can wring a better discount than Telonic's out of them.

 Ever since I'd started looking at what else Siglent had to offer in the £1000+ price bracket that might appeal to me, having broken my "Spending a £1000+ on T&M Virginity" on that SDS2104XPlus just over two months ago, I've been hankering after one of these SSA3000XPlus models ever since.

 The main reason I'm not going to even consider the merits of the cheap sub 100 dollar VNAs is simply because I've moved beyond the cheap FY6600 toy AWG class of T&M kit (as fine as that surprisingly turned out to be for the money) and feel it's high time to indulge myself with a better class of T&M kit rather than carry on struggling with any more bargain basement test kit, especially with Xmas being so close (an SSA3021XPlus would make an excellent early Xmas pressy right about now ).

 Like Dan Moos admitted, It's more a case of the pleasure of owning a nice shiny chattel than that of the pure utility of a 100 dollar cheapy that can suffice for my initial needs. If he's still monitoring this topic (and it's not already too late), I'd advise him to go for the Siglent rather than the Rigol. After all, if you're considering a 1000 dollar plus spend for an inferior (IMHO) offering when for just another 3 or 4 hundred dollars more you can have so much more SA for your money, you might as well push the boat out just that little bit further and be hung for a sheep as for a lamb.

John

[tautech]

JBG
Telonic's free TBCAAS1 is just their promo, it's not something that's offered by Siglent. That they choose to offer such a kit to get you started is great and commendable on their part. 

[Johnny B Good]

@tautech

 I've been chewing it over and concluded that Telonic are effectively offering a "5.5% discount" which they've spent on a useful connector adaptor kit on the customer's behalf. That however, won't stop me asking them for some discount when I make my enquiry on their "Best Price" If you don't ask, you don't get and it's always worth asking since the worst they can say is that they can't offer any further discount over and above the effective discount already provided in the form of that 'free' Tekbox 'gift'.

 They only had one each in stock (understandable for such high priced gear) and they've sold the 3021, hence the one and only 5 star customer feedback on only the 3021 model. I notice they've since sold the 3015 and 3075 units (but no further customer feedback) with only the 3032 remaining in stock. The 3021 I'm interested in purchasing is now only "Available on back-order, delivery normally 1 week". If I place an order on Monday, I may just beat the Xmas rush and receive it in time to place under the Xmas tree.

 I've just used the "Quick quote" button to enquire after a discounted price to get the ball rolling. I may have submitted an order by Monday afternoon, with or without discount (hopefully, they don't monitor EEVBlog topic threads on a regular basis).
I'll report back on the result of that sales enquiry in due course.

John

[tautech]

JBG
Let me throw out more for you to think about as a result of another SA thread question.
Have a look at this post and follow the links for the promo's running on Siglent SA's.
https://www.eevblog.com/forum/rf-microwave/which-one-would-you-recommend-siglent-ssa3032x-r-or-rigol-rsa3030n/msg3337310/#msg3337310

Specifically if you are planning to do any EMI work the EMI bundle is pretty good value compared to normal pricing.

[Noy]

Hm, EMI licence is hackable.
And on Aliexpress you get really cheap near field probes which work quite well.
Also see daves video on diy probes. Siglents offer is not worth it.
And calkit offer is only available with VNA device for VNA price.. But you can hack..

[tautech]

Hm, EMI licence is hackable.
And on Aliexpress you get really cheap near field probes which work quite well.
Also see daves video on diy probes. Siglents offer is not worth it.
And calkit offer is only available with VNA device for VNA price.. But you can hack..

Yes to all however for accurate EMI work you need properly characterised EMI probes.
I've bought a few sets of the AliExpress EMI probes and they are just OK however the Siglent ones are much nicer.

FYI after nearly 2 years owning my SVA1032X the 120 hrs of free trial licenses are not even close to expiring so there is little need to be in some hurry to hack these unless you must make a SSA3021X+ a SVA1032X for urgent jobs at hand.
YMMV

[Noy]

Siglent ones are tekbox ones or ?
Same Dave reviewed. And with SA/VNA you can check characteristics by yourself or am i wrong?
Sure there is no hurry to hack. As far as i know you can revert hack if you need. But maybe siglent is closing this in a future update so im more comfortable with an already opened up device.

And if your searching hobiest grade things 400$ additionally  is expensive. I also looked for rigol 815-tg because for hobby its close to magic 1k mark. But then  did the jump because of the hack to VNA but even this are additional 600€ + ca. 150€ for Rosenberg parts as "cheap" VNA calkit + China Nearfield probes so ending up with 1750€ ca. Thats a big "hobby" budget..

[Johnny B Good]

@tautech

 As promised, I'm happy to report that I did get a favourable response to my sales enquiry with Telonic this Monday morning. I've just made payment on a nicely discounted SSA3021XPlus (still including the TEKBOX TBCAAS1 RF Accessory Set) just a few minutes ago.

 It's on back order so I don't expect to see delivery until next week which is fine - I did state I wasn't in any great hurry in my previous posts here. Hopefully, it should turn up in plenty of time for me to tie a bow on the box and wedge it under our Xmas tree. 


==============================================================================================
[EDIT 2020-12-09]

 I did receive my SSA just over a week after placing my order as anyone subscribed to the thread linked below will doubtless know :

https://www.eevblog.com/forum/testgear/siglent-ssa3000x-spectrum-analyzers/msg3355838/#msg3355838

 Apologies for taking so long to report back to this topic thread but I think anyone not already aware of my post to the other thread will understand why once they've read it. 

==============================================================================================

John

[Elasia]

I thought you caved and bought one a long time ago? welcome to the club

[Johnny B Good]

Siglent ones are tekbox ones or ?
Same Dave reviewed. And with SA/VNA you can check characteristics by yourself or am i wrong?
Sure there is no hurry to hack. As far as i know you can revert hack if you need. But maybe siglent is closing this in a future update so im more comfortable with an already opened up device.

And if your searching hobiest grade things 400$ additionally  is expensive. I also looked for rigol 815-tg because for hobby its close to magic 1k mark. But then  did the jump because of the hack to VNA but even this are additional 600€ + ca. 150€ for Rosenberg parts as "cheap" VNA calkit + China Nearfield probes so ending up with 1750€ ca. Thats a big "hobby" budget..

 VNA calibration kits can cost anywhere in the region of 500 to 1500 dollars which seems staggeringly expensive when you consider what they are. With a bit of care, it's possible to make a perfectly serviceable set for less than fifty dollars.

 I did a search for youtube videos on DIYing a VNA Cal kit and found these two videos by W0QE which nicely describe how to make a set of open/short/load adapters. He was, imho, the only one who actually understood the requirements and the issues in home fabrication of VNA calibration kits.

 The relevant videos are here:





 I highly recommend that anyone, interested in avoiding spending half as much again on a VNA calibration kit as they did on their Siglent/Rigol VNA/SA, view them, even if only to get a better understanding of just exactly what your 500 dollars buys you.

John

[tggzzz]

VNA calibration kits can cost anywhere in the region of 500 to 1500 dollars which seems staggeringly expensive when you consider what they are. With a bit of care, it's possible to make a perfectly serviceable set for less than fifty dollars.

You are buying a calibration kit that has itself been calibrated, and you therefore have a paperwork trail all the way to national standards.

If that doesn't matter to you, then you can indeed make uncalibrated calibration kits that may be perfectly suitable for your purposes.

[mawyatt]

If the cal kit is just for hobby use and not required to be traceable to a proper cal standard I use the cal kit that came with the NanoVNA SAA-2N. This is a type N male cal kit and has two RG142 cables (trying to find a source for these cables but no luck, seller (Zeenko) hasn't been helpful either after numerous requests). I recall someone did a comparison of this kit vs. a standard precision cal kit and the result was this SAA-2N cal kit wasn't too bad.

Earlier I had purchased a cheap type N Cal kit from eBay, the Open and Short compare favorably with the SAA-2N kit, but the Load doesn't. It's much longer than the Load on the SAA-2N, so not surprised it's different.

For SMA cal kit I'm waiting on the NanoVNA V2 Plus4 from Tindie (want to support the NanoVNA developers on both sides of the coin) which has a SMA cal kit included, I also recall someone did a comparison and the result was pretty good. In the meantime I've constructed my own very crude SMA cal kit using some SMA adapters and a cheap eBay SMA Load. The Open is just an SMA M-F extension. The Short is a SMA M-M extension type which has male pins on both ends, the external threaded end was filled with solder for the "short".

Anyway, think there are a few options for hobby type cal kits that don't break the bank

Best,

[Noy]

Of course i dont need the paperwork.
I think i will order the SDR-Kits SMA  Rosenberger parts from Mouser.

https://www.sdr-kits.net/Female-12%20GHz-Kit
I can measure the load with my Fluke 8840a with 4 wire. And i don't need a wooden box. And its better/cheaper to order from Mouser instead of UK from germany.
Im only unsure if i need only female ones or additional male ones. All cables i have are male so i need only male ones if i don't want to use cables directly on the Adapters...

I think BNC ones aren' affordable.. SDR kits are saying their bnc calkit is only gold to 600MHz. So i think SMA is the way to go for good / widely spread usability.
Additional purchased some Delock N to SMA Adapters (10GHz 89983 ones not the cheaper ones)

[switchabl]

I did a search for youtube videos on DIYing a VNA Cal kit and found these two videos by W0QE which nicely describe how to make a set of open/short/load adapters. He was, imho, the only one who actually understood the requirements and the issues in home fabrication of VNC calibration kits.

 The relevant videos are here:

[...]

 I highly recommend that anyone, interested in avoiding spending half as much again on a VNA calibration kit as they did on their Siglent/Rigol VNA/SA, view them, even if only to get a better understanding of just exactly what your 500 dollars buys you.

I think those videos show a couple of things:
- At 200-300MHz almost anything will do.
- Making a pretty good 2-3GHz 50 load is not too hard with a bit of care and a decent connector (at higher frequencies, it gets a lot more tricky). But then this is also pretty easy to buy. A cheap Minicircuits ANNE-50X+ would probably be fine. A while ago I bought a whole bag of Huber&Suhner 18GHz SMA terminations for 2€/piece on eBay.
- If you have a proper calibration kit already, you can easily make your own. In principle, if you get it properly measured, any set of stable standards that is sufficiently spread out on a Smith chart can be used for calibration. That is essentially how E-cals work.
- The naive approach without any characterisation/optimisation is okay-ish at 3GHz. If you used his first attempt for calibration without entering the correct delays there is an error of more than 3ps, you will probably end up with a residual source match error a bit worse than -30dB (assuming your load is sufficiently good not to be a limiting factor). Also of course your reference plane will be way off.

I would also recommend against trimming the open to have the same delay as the short. Unless you are making standards for a scalar analyzer or there is no way to enter cal-kit definitions on your VNA it really serves no purpose. If they have very different lengths, at some frequency the phase delay of the open and short will become very close/identical and the calibration math falls apart. But a few degrees really don't matter. Measure them and enter the correct values so the VNA can take them into account during calibration.

I think BNC ones aren' affordable.. SDR kits are saying their bnc calkit is only gold to 600MHz. So i think SMA is the way to go for good / widely spread usability.

Standard BNC connectors don't maintain 50ohm impedance, so they are not really suitable for calibration (at more than a couple 100MHz at least). There are special precision BNC connectors for 10GHz+ (often 75Ohm for broadcast applications) and expensive cal-kits for those, but it doesn't really make sense to mate those with normal BNCs.

[Noy]

THX for clarification.
So definetly the Rosenberger SMA parts because delay and other parameters are provided by SDR Kits.
But do i need female and male parts?

[switchabl]

It all depends on the devices you want to measure. Do they have female connectors (at least on one side)? Then you need the female calkit. Many PCBs, Minicircuits modules, filters, attenuators etc do. For simple things that don't need great accuracy (like maybe an occasional antenna with a male SMA), you can also get away by calibrating with the female kit and adding a f-f adapter. But everyone's needs are different. If you want to measure devices with male connectors frequently/accurately, you should get a male kit as well.

I'm also not sure what to recommend for a cheap male kit. I'm not as confident about the male SDR kits one as the female one. It may be fine, but I haven't seen any real data for it and I am skeptical about the dust cap open (as you probably know by now).

That being said, having a male load (or ten) is definitely useful. E.g. maybe you have something with more than 2 ports and need to terminate the rest. Any 12-18GHz name brand one (Rosenberger, Suhner, Minicircuits, Telegärtner etc) is probably ok. Just don't get those tiny ones where the pin is always rotates with the rest of the connector.

[mawyatt]

The NanoVNA SAA-2N has cal kit parameters for the supplied type N cal kit for use with NanoVNA-QT, they are both male and female. I got these files from one of the on-line tutorials.

Best,

[hendorog]

If you know someone with a proper cal kit then they can measure whatever parts you choose to use. Then you can try to fit the 'standard' properties to the measurements using software discussed here in the past. Metas VNA tools is one way.

That gives you a fitting error, which will have some effect on real world measurements depending on its magnitude. Better quality parts will fit better over a wide bandwidth. Crappy parts can still fit well, but only over a narrow bandwidth.

Instead of fitting, the better option is to just use your mates measurements directly, but that generally requires a pc, as many vnas don't provide that option.

Another consideration when buying cal kits is the variation between cal kits, when the cal kits all share one set of characterisation data. All cheap kits and most low cost kits are like this. High quality kits must be either individually characterised (as above) or mechanically tuned to fit the parameters. So by simply measuring a cheaper kit properly it can be improved.

So, if you have access to someone with a proper VNA cal kit, then get a kit with the highest quality parts in it. I have seen a Siglent 3.5mm/sma kit, and it has higher quality parts than my Kirkby kit. My sdrkits Rosenberger kit is lower quality IMHO.

If you don't have access to a proper cal kit, then characterisation data is king. Kirkby is the best here by far, of the low cost ones I have seen.

I'm happy to measure cal kit parts against my Kirkby one for the cost of postage. If that was done by a proper lab with calibrated gear then your cal kit would be traceable as pointed out by tgzzzz.

[Noy]

Nice but kirkby ones are also nearly 1/3 of the VNA price..

[hendorog]

Nice but kirkby ones are also nearly 1/3 of the VNA price..

Yes - but the VNA is nothing more than a (fairly simple) tool for comparing an unknown against a characterised cal kit.

The VNA is not the part you should be investing all of your money into... 

Edit: And as indicated, I did point out the cheap option - buy parts and get someone to measure them...

[0culus]

Nice but kirkby ones are also nearly 1/3 of the VNA price..

Get used to it. The cal kit is the heart of everything you do with a VNA; without a good one the instrument is pretty darn useless. I was ecstatic to find a great condition HP 3.5mm cal kit for a grand. That was a steal.