USB Spectrum Analyser 35MHz to 4.4GHz review & musings

[@M0UAW_IO83]

I'd recommend having a chat with Vitor, he's a nice guy and very helpful, the software has limitations and so does the hardware but some hardware is better than others, most of the cheap 'spectrum analysers' are clones of a design from a ham, I *think* it might have been the VNWA?

[@joaquimsilva7671]

The dip in the center of the spectrum is due to the fact that is a direct conversion, so the log amp see from -170KHz to 170KHz, ( the minus is the LSB and the + is the USB). Passing through zero ( DC ) the out of the log amp is a low value because the coupling is with a C, the out is really low just in the center. I think that the idea is to have a dip just in the center of the "peak", trying to get a good thing from it! 73´s CT4QW.

[@workstationf]

Hello . I saw your video and bought this spectrum analyzer but they didn't send me the WINNWT4 software. I couldn't find it anywhere, can you send me this? Thank you very much

[@cosmicstudio9848]

nice video, how can i buy one .. please suggest me a store link. Thank you

[@JAKOB1977]

Can you share that SW 4.09 org source not valid anymore and the newer version 4.11 keeps coming back with a syntax error? If you could upload 4.09 at one of the host files, as it is only 5mb It would be great. and what kind of antenna do you need for one of these to pick up these signals, as most I got in the household is usually intended for 2.4ghz or 5.4ghz and from RC,.

[@MarkG0MGX]

Sorry, but I dont seem to have the file anymore - I have looked but its not there - sorry :-(

[@antexterminator9373]

Thanks to this video I won't buy the 35-4400M usb spectrum analyser

[@Kevin_geekgineering]

basically it's another Chinese piece of junk, I regret wasted money this

[@Pieh0]

You have to calibrate it for SWR measurements :)

[@ottaviocrisafulli8065]

how to do? May you explain better?

[@volkerblock]

the notch is not artificial, but arises from the frequency response of the RC coupling of the direct heterodyne receiver. The low frequencies are not transmitted by the RC coupling, so they are reduced to zero, a notch. . The high frequencies are not transmitted either, the bandwidth should be small. Unfortunately it is still 100 or 200 KHz.

[@LutzSchafer]

Since you know the highpass characteristic (well if you do...), I am wondering if you could correct the dip by software. Obviously at the exact zero (DC) you would need to interpolate, but generally this might be possible and would enhance the value of this little turd. After all its just a linear system of equations and by inverse filtering one could almost completely remove the contribution of the RC filter (I think its a higher order LCR Butterworth, but not sure). In my field of work I am dealing with optical deconvolution and would see this as an analogon and a simple one on top that would not suffer much from being an ill-posed problem (except for the zero). Unfortunately this requires having the PC source code available to perform some changes.

[@volkerblock]

@@LutzSchafer ok, danke

[@megavoltus]

Thank you for yuor review. Long time I seek review for this analyzer. Very good review. But this analyzer is bull shit. I reccomend to buy Arinst SSA TG R2

[@TheGermanbeerable]

Hello max, do you maybe know an alternative that is better than the model in the video and cheapter than the Arinst SSA TG R2?

[@megavoltus]

@@TheGermanbeerable hello We made Arinst R2s Pls find

[@TheGermanbeerable]

@@megavoltus hey, thanks for the fast reply, i will definitely have a look :D

[@megavoltus]

@@TheGermanbeerable kroksw.com/shop/network-equipment/portable-spectrum-analyzer-with-built-in-signal-generator-arinst-ssa-tg-r2s/

[@TheGermanbeerable]

@@megavoltus thank you very much :) unfortunately that is too expensive for me.

[@KX36]

not knowing much about RF, is the notch because the thing sweeps the LO over the signal, directly downconverts without IFs and filters and ends up with an image? It seems to me like the thing is designed only to be used with the tracking generator as more of a network analyser and they haven't really designed it to be used as a spectrum analyser..

[@ihordark5994]

Please help! I am unable to calibrate my LTDZ spectrum analyzer.

[@tanmoypaul4301]

Sir, How I get this package in India??

[@sdgs5640]

Faire encore plus d'argent grâces au don oui

[@frankbaron1608]

you took it apart without trying it?

[@allancopland1768]

Hi Mark. That notch I suspect is because this device uses a heterodyning arrangement and it's going through zero beat. I wonder if you have a working copy of the software cause I can't find it anywhere! I've just ordered one of these with the intention of re-purposing it. STM32 + 2 decent 35-4400Mhz oscillators, a 25Mhx OCXO etc.... I think I can use it for 'better things' but of course it would be nice to test it first b4 I wipe the MPU and start again. :-)

[@MarkG0MGX]

The best I can find is a .rar file which I have placed here: www.qsl.net/g/g0mgx//BlogFiles/USBSpecAn/

[@MarkG0MGX]

I found a zip file too which is in the same location now.

[@euripedesjunior5798]

May i adjust a vhf duplexer using the 2ports?

[@MarkG0MGX]

Yes I would think so

[@Chaosfury50]

Maybe the notch is caused by the amount of samples it is taking and it somehow ends one sample collection at the beginning of the frequency to be detected and then takes another one thinking its 2 signals?

[@MarkG0MGX]

The manual for the alternative software has this to say on the notch: "This is the due to how the low-pass and high-pass filters are implemented to form the bandpass filter of the detector in the SMA/NWT devices: there will be a blind spot in the middle of the detector. As a result, when the detector bandwidth is greater than the signal to measure, it will be rendered with a notch, as the samples which cover the maximum signal amplitude are masked with the blind spot"

[@bigpimp347]

Would you be able to tune cavity filters for repeaters using these analysers ?

[@MarkG0MGX]

Yes certainly

[@bigpimp347]

@@MarkG0MGX would they be good enough for 1.6Mhz and 600Khz split and the accuracy be good, thanks..