Are Spectrum Analyzers like the cheap Aten AT6005 useful?

[Lawsen]

Here is an advertisement for an Atten AT6005 spectrum analyzer from 0.15 MHz 150 kHz to 1.050 GHz.  It is not in the audio frequency range.  The frequency is too high for seismograph.  It looks like a neat instrument, even it is not Rhode and Schwartz, Agilent HP, or Tektronix brands.  I have seen radio telescopes have these are the display for the receiver.  I cannot afford that.  

http://cgi.ebay.com/New-portable-Analog-Spectrum-Analyzer-1GHz-AT6005-/270714796012?pt=BI_Analyzers&hash=item3f07dbf7ec

Lawsen

[Mechatrommer]

i also been eyeing on spectrum analyzer.
why dont you choose something with track generator, i suspect it can be an important feature, like ATTEN AT5011 Track Generator 1050MHz

and i also recommend Signal Hound USB-SA44B 1Hz - 4.4GHz. good for 440MHz RF up to 10th harmonics analysis. If i have spare money, i'll get that USB SA. The drawback, its more expensive than 1GHz Atten, and you need a PC or netbook to operate that.

pls review if you got one, any SA

[saturation]

It might be, its very intruiging but I have no real need for one, the 1000e FFT is enough for me currently.  Like some other low cost instruments we need someone to review it for us and take a risk.

[deephaven]

i also been eyeing on spectrum analyzer.
why dont you choose something with track generator, i suspect it can be an important feature, like ATTEN AT5011 Track Generator 1050MHz

and i also recommend Signal Hound USB-SA44B 1Hz - 4.4GHz. good for 440MHz RF up to 10th harmonics analysis. If i have spare money, i'll get that USB SA. The drawback, its more expensive than 1GHz Atten, and you need a PC or netbook to operate that.

pls review if you got one, any SA

I've just bought an AT5011A from a vendor in Hong Kong. It came to England in just a few days. I haven't got time to do a full review, but I'm happy to answer any questions about it.

[saturation]

Great, good to hear.  Do you have a good sine signal source with dependable harmonic distortion specification, say for example rated at -90dBc? Can the analyzer detect your sources level of distortion?  Can you estimate its noise floor and does it live up to its published spec? 

i also been eyeing on spectrum analyzer.
why dont you choose something with track generator, i suspect it can be an important feature, like ATTEN AT5011 Track Generator 1050MHz

and i also recommend Signal Hound USB-SA44B 1Hz - 4.4GHz. good for 440MHz RF up to 10th harmonics analysis. If i have spare money, i'll get that USB SA. The drawback, its more expensive than 1GHz Atten, and you need a PC or netbook to operate that.

pls review if you got one, any SA

I've just bought an AT5011A from a vendor in Hong Kong. It came to England in just a few days. I haven't got time to do a full review, but I'm happy to answer any questions about it.

[Mechatrommer]

I've just bought an AT5011A from a vendor in Hong Kong. It came to England in just a few days. I haven't got time to do a full review, but I'm happy to answer any questions about it.

i would loved to hear any report on the usage and how it helps (or not) you with your projects. picture on real application, harmonics display etc. just shoot any, or even make a new thread, its highly welcomed.

[deephaven]

I need to set up some tests to answer those questions. I don't have a precision sine wave generator. I got it mostly for EMC pre-compliance testing. I intend making up some near field probes so that I can get an early measure of radiated and conducted emmisions.

I do have an HP rf signal generator, so should be able to measure it's absolute accuracy and sensitvity. The tracking generator will also make it ideal for measuring filter responses.

When I have a while, I take some measurements.

[deephaven]

I doubt it would have the dynamic range to do sensible distortion analyis of the sort you are describing.

I did fix up my signal generator to give you an idea of the sensitivity. I tried at 10 MHz and 100 MHz and the results were the same. Here is a -90 dBm 100 Mhz carrier:

Great, good to hear.  Do you have a good sine signal source with dependable harmonic distortion specification, say for example rated at -90dBc? Can the analyzer detect your sources level of distortion?  Can you estimate its noise floor and does it live up to its published spec? 

i also been eyeing on spectrum analyzer.
why dont you choose something with track generator, i suspect it can be an important feature, like ATTEN AT5011 Track Generator 1050MHz

and i also recommend Signal Hound USB-SA44B 1Hz - 4.4GHz. good for 440MHz RF up to 10th harmonics analysis. If i have spare money, i'll get that USB SA. The drawback, its more expensive than 1GHz Atten, and you need a PC or netbook to operate that.

pls review if you got one, any SA

I've just bought an AT5011A from a vendor in Hong Kong. It came to England in just a few days. I haven't got time to do a full review, but I'm happy to answer any questions about it.

[saturation]

Thanks Nigel, at the least I can see the -90dB and the noise floor, gives me an idea of what its sinad is, looks like the floor is in -100dB range.

It looks like it could since you still have a touch left before the floor at -90dB, can you amplify the 100 MHz to maximum amplitude for the screen, and see if any spurs appear in the trace?

I doubt it would have the dynamic range to do sensible distortion analyis of the sort you are describing.

I did fix up my signal generator to give you an idea of the sensitivity. I tried at 10 MHz and 100 MHz and the results were the same. Here is a -90 dBm 100 Mhz carrier:

[deephaven]

Here it is with a 10 MHz -40 dBm signal showing harmonics at 20 MHz and 30 MHz. I don't know if that is down to the generator. I couldn't see any harmonics beyond that with that level of signal. If I try to increase the signal level beyond that, the base line starts to come up which I believe is indicating that the analyser is being overloaded rather than an increase in broadband noise.

[saturation]

Thanks Nigel, that says a lot. Much appreciate your time for testing.

[slburris]

There's always the build it yourself route:

http://www.scottyspectrumanalyzer.com/

Up to 3Ghz. + Tracking Generator + VNA

Scott

[nyo]

Nigel,
Would you be able to show us more pictures of it in action, maybe 2 frequencies coming in with a marker delta and the freq + amplitude displayed from one signal to other...

[deephaven]

Nigel,
Would you be able to show us more pictures of it in action, maybe 2 frequencies coming in with a marker delta and the freq + amplitude displayed from one signal to other...

I only have one signal generator, so I can't really do that. Which parameter were you interested in?

[nyo]

Thanks for the quick reply. I just noticed it's an analog analyzer, nevermind.

[tecman]

I looked at the chinese units when I was in the market, but I was nervous about how well they would work.  Scope is one thing, but a spectrum analyzer is a bit more complex and harder to copy.  They certainly seem to have limitations on the BW settings, readout accuracy, attenuator steps and frequency accuracy.  I ended up buying a Tek 2714 on eBay for $ 600.  Had a small problem that none of the faceplate buttons would respond, but turned out to be a 74LS... that had crapped out on the faceplate PCB.  3 hours each disassembly and reassembly plus a 50 cent chip fixed the problem.  The 2714 is a 2712 with additional capabilities for TV cable network testing.  9kHz to 1.8 GHz range, with AM, FM and video demodulators built in.  You can exit the cable TV mode and have a standard analyzer.  The other change I made was from a 75 ohm input to a 50 ohm input.  Simple enough.  The faceplate input jack is F/BNC to SMA behind the panel.  This jack has a 25 ohm R built in, and connects to a 50ohm attenuator.  I bought a BNC to SMA bulkhead fitting, which was almost exactly the same size, with no internal R.  Recal'ed the amplitude and now it is a 50 ohm unit.  Works great and built like a tank.  Only negative is no TG, but for most of what I need, not a problem.

paul