shopping for a spectrum analyzer

[worsthorse]

I am shopping for an entry level spectrum analyzer with a tracking generator.  I spend most of my time below 50MHz working with amateur radio gear.  I have been looking at used Instek GSP-810s. At 400 bucks or so, especially compared to the SDR-based homebrew unit I am using now, they seem like a pretty good deal.  I've looked at old used gear too but, honestly, I don't know enough about the high end stuff to know a good deal from bad and I certainly don't have the expertise (yet) to repair such stuff.

I've noticed though that there are very few reviews of the entry SAs in general and the 810 in particular. Anyone have one? Use one? Have an opinion?  Is it just silly to think I can get a decent SA for under a thousand bucks? two thousand?  Is there some used HP, etc SA I really should consider instead, as painful as it will be for my wallet? 

Thanks in advance! - b

[tautech]

These are pretty well thought of on the forum.
https://www.eevblog.com/forum/testgear/siglent-ssa3000x-spectrum-analyzers/
https://www.eevblog.com/forum/testgear/hack-of-sigllent-spectrum-analyzer-ssa3021x/
https://www.eevblog.com/forum/blog/eevblog-892-siglent-ssa3021x-spectrum-analyser-teardown/

[nctnico]

There are lots of SAs from Advantest on Ebay and good deals can be had on compact units like the R3131 / R3131A. However many don't have a tracking generator and I think the reason is that a tracking generator isn't really usefull. For example: If you measure an antenna or filter you'll also want phase information so you can see what you need to modify in your circuit. For that you'll need a vector network analyser. A vector network analyser can be used as an LCR meter and a spectrum analyser as well so it is also a multi function instrument.

[biot]

These are pretty well thought of on the forum.
https://www.eevblog.com/forum/testgear/siglent-ssa3000x-spectrum-analyzers/
https://www.eevblog.com/forum/testgear/hack-of-sigllent-spectrum-analyzer-ssa3021x/
https://www.eevblog.com/forum/blog/eevblog-892-siglent-ssa3021x-spectrum-analyser-teardown/

It is considered proper in conversations like this that you disclose the fact that you are a Siglent dealer. By not doing this, and instead shamelessly astroturfing your brand, you will achieve rather the opposite effect from what you intended.

[srce]

These are pretty well thought of on the forum.
https://www.eevblog.com/forum/testgear/siglent-ssa3000x-spectrum-analyzers/
https://www.eevblog.com/forum/testgear/hack-of-sigllent-spectrum-analyzer-ssa3021x/
https://www.eevblog.com/forum/blog/eevblog-892-siglent-ssa3021x-spectrum-analyser-teardown/

It is considered proper in conversations like this that you disclose the fact that you are a Siglent dealer. By not doing this, and instead shamelessly astroturfing your brand, you will achieve rather the opposite effect from what you intended.

It does say that in his signature - the line of text below what you quoted.

[worsthorse]

spent the morning looking at the 810 specs. now i know that won't work. also found a thread on used equipment which is, unfortunately, 25 pages long. looks like the HP 8591 is a contender in the old category, and the siglent/rigol gear in the new. it also looks like i am not going to get away with spending less than $1300 - $1800, which may put it out of range.

i am going to dig through that 25 page thread some more. any guidance on the old gear is appreciated. there seems to be plenty to read on the siglent/rigol gear. thx.

[videobruce]

Attached are two spreadsheets on some current lower cost SA's with added details/comments from my experience with them. These are either current or fairly recently discontinued.
No 'boat anchors'. 

Updated & revised lists; added new Instek models!

[nctnico]

Sigh... more test equipment dealers chiming in and parading their stuff without even considering the OP's question. 

@wch: I don't think the GSP-810 is a good buy at around $400. I'd spend a bit more and get a used digital spectrum analyser. With some research and patience good deals can be found on Ebay.

[kgharibyan]

May be this one ?
http://www.deepace.net/shop/kc901s/


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[bozidarms]

By far, Siglent's SSA3000X are the best choice!

[videobruce]

Hello Videobruce - can you also add the recently launched FPC1000 from Rohde & Schwarz ?
It is a model upgradable by software keys - basic model starts at 1550 euros.

Interesting, but R&S isn't a huge name in the states and their UI is (or has been) unconventional which I noted in my comparison charts. This has been reflected elsewhere by others.

May be this one ?
http://www.deepace.net/shop/kc901s/

Never heard of them and there isn't a US distributor. 

[rstofer]

The 500 MHz Rigol DS705 is just under $700.  It doesn't have the noise specs of the Siglent SSA3000 or even the better Rigols but maybe it will do the job.  Or not...

https://www.rigolna.com/products/spectrum-analyzers/

I would rather have a new device with a warranty.  Buying used test equipment seems risky even though it has worked out well for me.
But my signal generator, DSO and power supply were bought new.  I have a used scope and a couple of used bench DMMs and they all work fine.

[videobruce]

I updated those lists I posted.

[james_s]

I only buy used test gear, it may be a bit of a gamble but I've saved vast sums of money and ended up with much better gear that I could have afforded buying new. I can't actually think of a single instance where I got screwed and the item turned out to be junk. I often buy known defective equipment and more often than not the problem turns out to be simpler than expected. It saves enough that I could afford to be burned now and then.

[hendorog]

May be this one ?
http://www.deepace.net/shop/kc901s/


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Have seen those products advertised for quite a while. The newer KC901V model has some improvements which improve accuracy apparently. Would be interesting to see it tested.
"The KC901V is a RF multi-instrument integrating VNA, spectrum analyzer, field strength meter, and a low-frequency signal generator. It can do complete signal port vector measurement and 2-ports simple vector network analyzing."

There are also the SignalHound products, Spectrum and Track gen bundle for $1472.
https://signalhound.com/products/4-4-ghz-scalar-network-analyzer/

[G0HZU]

I only buy used test gear, it may be a bit of a gamble but I've saved vast sums of money and ended up with much better gear that I could have afforded buying new. I can't actually think of a single instance where I got screwed and the item turned out to be junk. I often buy known defective equipment and more often than not the problem turns out to be simpler than expected. It saves enough that I could afford to be burned now and then.

Same for me. I try and be patient and pick up used bargains either ex rental or from ebay or from the skip/dumpster at work. The most I've spent on a spectrum analyser is £1000 about 6 years ago for an ex rental HP8566B 22GHz analyser. At the time this was a huge bargain not to be missed. But before that the most expensive was my old Advantest TR4172 at £400. Most recent is an old Tektronix RSA3408A RTSA rescued from a trip to the skip at work. It's a bit of a dog when used as a conventional spectrum analyser but is very powerful as an RTSA. It's horrible to use but it was free

[joeqsmith]

I am shopping for an entry level spectrum analyzer with a tracking generator.  I spend most of my time below 50MHz working with amateur radio gear.  I have been looking at used Instek GSP-810s. At 400 bucks or so, especially compared to the SDR-based homebrew unit I am using now, they seem like a pretty good deal.

What is it that you need to do that the one you have doesn't support?   

[videobruce]

There are also the SignalHound products, Spectrum and Track gen bundle for $1472.
https://signalhound.com/products/4-4-ghz-scalar-network-analyzer/

In that price range, you might as well get the Siglent.
One dedicated device, not two that are severely limited in what they can do. Actually, don't you need a Laptop to tie the two pieces together??

Doing more 'new model' research, I stumbled across two new models from Instek which are basically variations in the existing 9300, one apparently marketed to the Siglent/Rigol crowd.
This two spreadsheets 12 posts back now reflect the addition.

[G0HZU]

One dedicated device, not two that are severely limited in what they can do.

The Signalhound SA44 can act as an SDR and display a ham band and demodulate typical ham signals on the HF bands. I don't think the Siglent can do this. Also the phase noise of the Signalhound is pretty decent on the HF bands.

By comparison the Siglent's phase noise is going to be awful, really awful for serious monitoring of the HF bands. Maybe not PLay Doh noise performance but pretty grim unless you just want to look for medium to big signals rather than little signals next to big signals.

[videobruce]

Anyone else on those observations? (HF phase noise)

[G0HZU]

For an extreme example I can show the noise performance of my dumpster RSA3408A on 14MHz. This analyser has very low phase noise on the HF bands because it feeds direct to the 14bit ADC for all frequencies up to about 40MHz and can easily detect a signal 100kHz away that is -80dBc on the 14MHz (20m) ham band. It could easily manage -90dBc with the analyser set to a typical comms bandwidth of 3kHz on the HF bands.

But I've drawn in red what I think the Siglent analyser noise will look like. It will totally mask the smaller signal. I'd expect the signalhound to be better than the Siglent here but obviously it won't match the old Tek analyser. All of my old school spectrum analysers can detect the -80dBc signal with a RBW of 3kHz but the HP8566B and the HP8568B struggle here a bit. My old Advantest analyser does well here as it has -128dBc/Hz phase noise at 100kHz offset. I think the Siglent manages about -98dBc/Hz here. I'm going to guess that the Signalhound will manage -120dBc/Hz here although I've not used one.

[hendorog]

There are also the SignalHound products, Spectrum and Track gen bundle for $1472.
https://signalhound.com/products/4-4-ghz-scalar-network-analyzer/

In that price range, you might as well get the Siglent.
One dedicated device, not two that are severely limited in what they can do. Actually, don't you need a Laptop to tie the two pieces together??

Yes you need a laptop/PC. That and the lack of knobs does affect its convenience on the bench, but the trade-off is portability and 'natural' PC access to  device for e.g. data and screenshots. It's a great device for the inquisitive as you can pick it up and use it anywhere and power it from a laptop.

There are limitations but hardly 'severely limited'. Certainly worth considering in competition with the other products you have included in your SS.
The main limitation is the switching IF method used to remove images. This is a pain when looking at signals which hop around but not an issue for normal ham stuff.
For such signals you need to switch it off and deal with any images or use max hold.

There are some advantages which I think are unique in the price range:
* Very portable
* Modular
* Higher frequency by quite a margin than anything in the price range
* Lowest cost
* PC integration (Labview available, HDSR available, GNURadio not yet)

[james_s]

I've had a PC based Bitscope for years and have never found it to be particularly convenient as a scope. Sure it's nice to be able to capture and save easily on the PC but using a mouse or touchpad is not nearly as convenient as buttons and knobs on a standalone device. Also I've had issues with the USB port locking up unless an isolator is used, and driver issues, I never was able to get it to work properly on my current Win7 laptop, neither does my USB to DMX interface, they work fine on the old XP laptop though.

[G0HZU]

The main limitation is the switching IF method used to remove images.

I've often wondered how well this works in practice with the SA44B. How does it deal with wideband signals that look like noise or wideband pulsed signals? For ham use and the odd bit of EMC sniffing I suspect that the Signalhound would be quite a powerful tool.

I wouldn't want to buy one but I'd  be interested to see how the unconventional image rejection system performs.

[hendorog]

The main limitation is the switching IF method used to remove images.

I've often wondered how well this works in practice with the SA44B. How does it deal with wideband signals that look like noise or wideband pulsed signals? For ham use and the odd bit of EMC sniffing I suspect that the Signalhound would be quite a powerful tool.

I wouldn't want to buy one but I'd  be interested to see how the unconventional image rejection system performs.

Those types of signals would be kicked out by the image rejection, and it would need to be turned off to see them reliably.

There is however a narrowband  (<250kHz) 'real-time' mode which will capture fast modulating signals, and the API could presumably be used to assemble many of these to view a wider bandwidth.