Author Topic: 6Ghz portable spectrum  (Read 8047 times)

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Offline ebclr

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Online PA0PBZ

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Re: 6Ghz portable spectrum
« Reply #1 on: August 31, 2016, 11:55:34 am »
I don't own one but depending on what you want to use it for the 570KHz RBW could be a dealbreaker.
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Offline Bicurico

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Re: 6Ghz portable spectrum
« Reply #2 on: August 31, 2016, 12:46:50 pm »
Hi,

My guess is that this device is closely based on the SMA Simple Spectrum Analyser 138MHz-4.4GHz, which costs around 60 Euro on eBay (with free shipping).

It probably uses a different mixer to support the higher bandwidth and the seller removed the (pretty) useless signal generator.

All these devices come from a long sequence of cheap analyzers, the NTW series (NWT400, NWT500, NWT4000...), which offer more functionality at a higher price (real tracking generator, software selectable attenuators, etc.).


Take a look at:

- http://vma-satellite.blogspot.pt/ (my blog)
- https://www.eevblog.com/forum/testgear/presenting-my-new-software-for-the-sma-spectrum-analyzer-138mhz-4-4ghz/msg1015544/#msg1015544

This is not to say that the device is no good. However, you should understand the limitations.

Main issue is the SLOW refresh rate. It is measured not in SWEEPS relative to RBW/VBW but rather in samples/second. The SMA Simple Spectrum Analyser 138MHz-4.4GHz needs around 2-3 seconds for 500 samples: take the frequency span and divide it by the number of samples and you get your resolution. The video at https://www.youtube.com/embed/I50BaOcy_0s seems to show an acceptable refresh rate, but bear in mind that it is showing a bandwidth of just 70MHz with "288 pts" (=samples).

Also, keep in mind accurancy.

The software itself looks good and offers a lot of functionality. Thumbs up. My comments are not intended to push him down, but rather to keep interested people with their feet on the ground: you cannot get a propper spectrum analyzer in this price range.

Regards,
Vitor

 
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Online hendorog

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Re: 6Ghz portable spectrum
« Reply #3 on: August 31, 2016, 07:12:23 pm »
Instead of a different mixer it is probably just using a different PLL chip. The Maxim MAX2871 matches the frequency range.
 

Offline Yansi

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Re: 6Ghz portable spectrum
« Reply #4 on: August 31, 2016, 07:24:44 pm »
I have borrowed from a friend the 4.4 gig version, it is a complete piece of junk. Never worked properly, even couldn't work out how to use it as a wobler or anything else barely useful. Not mentioning that it does NOT include it's own software, it uses a PC software stolen from other peoples projects.

 

Online PA0PBZ

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Re: 6Ghz portable spectrum
« Reply #5 on: August 31, 2016, 07:40:43 pm »
...it uses a PC software stolen from other peoples projects.

Are you sure it's the same thing? I'm in no way defending this product and I'm sure that it is no alternative to a real SA but they are talking about android software, not pc.
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Offline Yansi

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Re: 6Ghz portable spectrum
« Reply #6 on: August 31, 2016, 07:58:08 pm »
I am offending the 4.4Ghz product that Bicurico has talked of.  He might be onto something, that the advertised 6GHz thingy (with that android something) is only a beefed up version of what is already known.

I only wanted to point out, that this 4.4GHz thing is barely usable as a measuring device, it is only a toy for kids. I mean really, I haven't been able to do anything useful with it.

Originally, I have borrowed that from a friend which has bought it from fleabay (but never used it!) so I have had to figure out. Wanted to sweep a simple lowpass filter, but no success, the thing is junk. Both HW and SW wise.
 

Offline Bicurico

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Re: 6Ghz portable spectrum
« Reply #7 on: August 31, 2016, 09:31:56 pm »
I am offending the 4.4Ghz product that Bicurico has talked of.  He might be onto something, that the advertised 6GHz thingy (with that android something) is only a beefed up version of what is already known.

I only wanted to point out, that this 4.4GHz thing is barely usable as a measuring device, it is only a toy for kids. I mean really, I haven't been able to do anything useful with it.

Originally, I have borrowed that from a friend which has bought it from fleabay (but never used it!) so I have had to figure out. Wanted to sweep a simple lowpass filter, but no success, the thing is junk. Both HW and SW wise.

Please let me disagree with you in a friendly way.

The device mentioned by the OP is a different device than the "SMA Simple Spectrum Analyzer 138MHz-4.4GHz" sold on eBay from China at about 50-60 Euro with free shipping.

It is a different design, featuring a different case with additional shielding, an internal battery and a Bluetooth module. It comes with a custom software for Android, which looks quite nice and professional.

The whole package is sold for 399 US$. Personally, I find the price a bit steep when compared to the pure "SMA Simple Spectrum Analyzer 138MHz-4.4GHz" hardware, but if you add taxes, import duties, extra battery, BT module, custome casing, etc., and SOFTWARE and SUPPORT, it might be reasonable - who am I to discuss that.

I just wanted to point out that the OP is NOT buying a real spectrum analyzer. Period. It is a much lower spec device that allows to see the spectrum, but not to carry out calibrated measurements. The guy selling the device is honest and actually says so on his web page! Again, nothing to point out and I do have to give him  :-+ for his nice design.

Would I spend 400 US$ on it? No. I purchased a Siglent SSA3021X, which is the most affordable REAL spectrum analyzer, with the best price/performance ratio on the market (if you can live with 9kHz to 2.1Ghz or 3.2GHz if hacked). But this doesn't make it a "toy" or "garbage".

Now to the "SMA Simple Spectrum Analyzer 138MHz-4.4GHz".

You are 100% correct when you say it doesn't work when you try to use the "tracking generator" and the included software, though it is a pretty good software, it simply wasn't designed for this device! Why? Because this device is a cut down version of a clone of a clone of a clone of the original device for which this software was made in the first place. The original NWT series featured a working tracking generator, software switchable attenuators, etc.!

On top of it, the Chinese sellers on eBay just include this freeware/shareware without any consent of the original author, who is really fed up getting complaints or questions by mislead customers, which he has nothing to do with.

But the question is: is the "SMA Simple Spectrum Analyzer 138MHz-4.4GHz" just garbage?

No it isn't! After my first disappointment, I went on and wrote my own software for it. And though people might find it silly or useless, it does work for me and guess what: it does EXACTLY what I wanted in the first place: it shows me the spectrum from 138MHz up to 4.4GHz, it can render a waterfall diagram and has other features, too. You are invited to try my software FOR FREE.

No offense, but I think the "6 GHz portable spectrum" is ledgit, in my opinion slightly overpriced and peope should not have too high expectations.

The "SMA Simple Spectrum Analyzer 138MHz-4.4GHz" is a very cheap device, great for introduction into spectrum analyzers and can actually be used to VISUALIZE (not accuratly measure) the spectrum, i.e. for CATV or SAT monitoring.

Hope this clarified things a little.

Hera are my links again, as they probably were ignored despite the fact that they show what is possible with this class of devices:

- http://vma-satellite.blogspot.pt/
- https://www.eevblog.com/forum/testgear/presenting-my-new-software-for-the-sma-spectrum-analyzer-138mhz-4-4ghz/msg1015544/#msg1015544

Regards,
Vitor

Online hendorog

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Re: 6Ghz portable spectrum
« Reply #8 on: August 31, 2016, 09:53:44 pm »
Would I spend 400 US$ on it? No. I purchased a Siglent SSA3021X, which is the most affordable REAL spectrum analyzer, with the best price/performance ratio on the market (if you can live with 9kHz to 2.1Ghz or 3.2GHz if hacked). But this doesn't make it a "toy" or "garbage".


"Siglent SSA3021X, which is the most affordable REAL spectrum analyzer _with a screen_"

Fixed that for ya.

The Signalhound SA44B is the most affordable REAL spectrum analyzer IMHO. This isn't bashing the Siglent at all, as by all accounts it is a very nice product at a very fair price.
But the fact is the SH is significantly more affordable, considering everyone already has a laptop, and it also has decent performance.
 

Offline Bicurico

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Re: 6Ghz portable spectrum
« Reply #9 on: August 31, 2016, 10:01:38 pm »
@hendorog: I totally accept your fix!

I totally forgot about the Signalhound product range - my mistake.

And no bashing at Rigol, either. Good products at fair price. The Siglent just came out more agressively - probably Rigol will adjust, soon.

And while I am at it: never forget eBay and the great second hand spectrum analyzers and "RF Test Equipment" (spectrum analyzers in disguise).

All these are much more mature products than the "SMA Simple Spectrum Analyzer 138MHz-4.4GHz" and all its clones.

Regards,
Vitor

Online hendorog

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Re: 6Ghz portable spectrum
« Reply #10 on: August 31, 2016, 10:11:08 pm »
@hendorog: I totally accept your fix!

I totally forgot about the Signalhound product range - my mistake.

And no bashing at Rigol, either. Good products at fair price. The Siglent just came out more agressively - probably Rigol will adjust, soon.

And while I am at it: never forget eBay and the great second hand spectrum analyzers and "RF Test Equipment" (spectrum analyzers in disguise).

All these are much more mature products than the "SMA Simple Spectrum Analyzer 138MHz-4.4GHz" and all its clones.

Regards,
Vitor


Yep agree, all very good points. Thanks for what you are doing for everyone by shining some light on these "SMA Simple Spectrum Analyzer 138MHz-4.4GHz" products too.
 

Offline dr_dax

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Re: 6Ghz portable spectrum
« Reply #11 on: March 10, 2018, 08:08:23 am »
Hi, All!
I'm developer of Arinst SSA and other Arinst analyzers. If you have any questions, I'm ready to give answers. :)
About high price. We spent lot money for design hardware and software. But I have good news, price will reduce down again and again. 
In soonest time we start produce new Arinst with display and TG.
I see my goal in made cheapest analyzers for all!
 

Offline dr_dax

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Re: 6Ghz portable spectrum
« Reply #12 on: March 10, 2018, 08:48:01 am »
What you mean? Please write in details.
 

Offline asdf

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Re: 6Ghz portable spectrum
« Reply #13 on: November 12, 2018, 10:12:38 pm »
Hi
I've just received the Arinst SSA TG. I didn't try any measurements yet but I've got already a few questions:
1. Is it possible to turn on the input attenuator without using tracking generator?
2. It is possible that after turning on "generator" and "tracking" the "generator" can be turned off while "tracking" is still turned on (refresh time is then as low as with tracking generator but dynamic range as it were off). Is that a bug in UI ("tracking" without "generator" seems to make no sense)?
3. What is the difference between normal end extended (>3GHz) range? Is the extended range work the same way? When I turn on tracking generator (input and output not connected) I can see discontinuities at 3GHz and 5.26GHz (I mean much lower dynamic range exactly between these two frequencies) - what are they?
4. When the generator (not tracking) is turned on I can see a big spur above 3GHz. Is it something that can be explained and taken into account while measurements in extended range? Why the generator introduces a spur when it's not connected to the input but only turned on?
I know it's advertised as 3GHz, I'm asking about the extended range because it can be useful to know something more about possibilities and limitations in that range.
Software and firmware version: 1.0.2
 

Offline HighVoltage

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Re: 6Ghz portable spectrum
« Reply #14 on: May 22, 2020, 01:30:35 pm »
I am looking for a low cost spectrum analyzer for the 433 MHz range to test some sensors
and just came across this instrument.

It seems this one is now available with touch screen.

Does anyone here have experience with this spectrum analyzer?
How reliable is it?

Thanks

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