Using the "138MHz-4.4GHz USB SMA Source/Signal Generator/Simple Spectrum Analyzer" for TV/CATV/SAT

[blademedia]

scopus

"Best" I can find is here which says "stock imminent" - which probably means "whenever". Never mind, will have to try to find alternatives (some already possibly in sight from Televes, as on the SDR thread I referred to).

One here
Global Communications Split 4AF - 4 Way Active Splitter | eBay

 

[scopus]

Good price!

 

[Llew]

One here
Global Communications Split 4AF - 4 Way Active Splitter | eBay

Thanks for that. Think I might have nabbed the last one - hope everybody who wanted one got one too

 

[jeallen01]

Morning

Quite a lot of Global active splitters (but not the 4-way at present) and the equivalent 2 & 4 way Labgear versions now found to be available here at CPC (one of my favourite suppliers - bar none) and cheaper than ebay or Amazon - & no P&P on orders over £5 +VAT.

PS: possibly won't be posting much on Fri /Sat after the new dishwasher arrives - having woken up to water on the kitchen floor this morning (and confirmed by running a cleaning cycle when it leaked again)

 

[John]

Example of "temporary" DATA @ 55.5°W , thanks to the Waterfall !


View attachment 100597

... Another little interesting thing the hardware / software has picked up on is this marker at 18.504 V GHz ....
Promax is on it's lowest span of 10MHz, vma is on 8MHz span ..... two different interpretations of that signal, which one is right ...Promax / vma / or both ?

 

[vma]

Hi,

I think you are looking at a double sideband amplitude modulation (DSB-AM) (see Sideband - Wikipedia).

The SMA device has quite a high resolution, mind you!

Most field meters will not allow user selectable RBW (Resolution Bandwidth). The only exception I know is the Deviser S7000 and Deviser S7200 field meters, better known as TV Analyzer (great devices, btw., with full TS analyzer on board).

The SPAN has nothing to do with RBW: it just selects the start and end frequencies being rendered in the spectrum.

Your Promax will then internally adjust to whatever RBW the engineers implemented, which certainly has a lower resolution than what you are seeing in my software. This causes the signal to be averaged out. See this picture:

Source: Resolution Bandwidth (RBW) - National Instruments

Try to render the same signal in my software with less samples: start with 500 samples then go to 250 samples, 200 samples and finally 100 samples. At a given point you should see the same signal as on your Promax.

My point is: while the spectrum on my software has a lower refresh rate than your Promax HD Ranger+, it will show the spectrum at higher resolution (read: lower RBW). Try to set the samples at 1000 in my software!

As opposed to normal spectrum analysers, you cannot directly select the RBW in my software, because the SMA device itself works by specification of the number os samples. So I did it the other way around: you specify the samples and the software displays the relevant RBW.

Regards,
vma

 

[John]

Hi,

I think you are looking at a double sideband amplitude modulation (DSB-AM) (see Sideband - Wikipedia).

The SMA device has quite a high resolution, mind you!

Most field meters will not allow user selectable RBW (Resolution Bandwidth). The only exception I know is the Deviser S7000 and Deviser S7200 field meters, better known as TV Analyzer (great devices, btw., with full TS analyzer on board).

The SPAN has nothing to do with RBW: it just selects the start and end frequencies being rendered in the spectrum.

Your Promax will then internally adjust to whatever RBW the engineers implemented, which certainly has a lower resolution than what you are seeing in my software. This causes the signal to be averaged out. See this picture:

Source: Resolution Bandwidth (RBW) - National Instruments

Try to render the same signal in my software with less samples: start with 500 samples then go to 250 samples, 200 samples and finally 100 samples. At a given point you should see the same signal as on your Promax.

My point is: while the spectrum on my software has a lower refresh rate than your Promax HD Ranger+, it will show the spectrum at higher resolution (read: lower RBW). Try to set the samples at 1000 in my software!

As opposed to normal spectrum analysers, you cannot directly select the RBW in my software, because the SMA device itself works by specification of the number os samples. So I did it the other way around: you specify the samples and the software displays the relevant RBW.

Regards,
vma

... Thanks for that detailed explanation Vitor, i'm sure that will be of great interest to others as well.

 

[scopus]

As regards to paying for a never ending license for Vitor's software, I will gladly pay and if others were to send payment via PayPal as a GIFT then surely this not cause you any issues for Vitor.
But of course it is up to the great man himself......

 

[John]

Try to render the same signal in my software with less samples: start with 500 samples then go to 250 samples, 200 samples and finally 100 samples. At a given point you should see the same signal as on your Promax.

... At 100 samples it resembles the Promax, at 200 samples it just starts to change , exactly as you say.

 

[John]

As regards to paying for a never ending license for Vitor's software, I will gladly pay and if others were to send payment via PayPal as a GIFT then surely this not cause you any issues for Vitor.
But of course it is up to the great man himself......

... Ditto ;)

 

[jeallen01]

As regards to paying for a never ending license for Vitor's software, I will gladly pay and if others were to send payment via PayPal as a GIFT then surely this not cause you any issues for Vitor.
But of course it is up to the great man himself......

scopus
Sounds like a very good idea (and probably a lot better than the one I had up my sleeve).

 

[vma]

Hi,

I will accept donations (10€, 10£, 10US$ - whichever is more convenient and cheaper) through my PayPal account. I have informed myself and there is no worries, as long as I don't make a business out of it, which I won't... So far I have given out around 20 activation codes - so you guys get an idea of the business dimensions!

Anyway, I want to make the following very clear:

1. I am giving out free codes and intend to continue doing so. To make things easier for me, these free codes will terminate on the last day of March, June, September or December - you always get activation codes for the next deadline.
2. You may request as many renewals as you want.
3. You may request several codes for your main PC, laptop, tablet, etc.
4. Donations are NOT mandatory at all, they will not give any extra functionality - but I will return the good-will with a permanent activation code for your main PC, laptop, tablet, etc.
5. Donations will NOT entitle to any special support or feature request - all functionality can be extensively tested with free activation codes and new functionality is implemented according to my ideas, people's suggestions, feasibility, etc.
6. Donations will help me paying for additional devices, so I can possibly enhance the functionality of the software and better support devices, which I currently don't own.

Donation instructions will be included in future releases, but basically consist of these lines and the required e-mail address of my PayPal account.

I do appreciate some of you being eager to make a donation - it means a lot more to me than the simple value of the donation itself.

I will explain:

I am a metallurgical and materials science engineer and I work with CAD/CAM/CAE systems. I have no formal education on RF, broadcasting, signal distribution, etc.

However, in the last 20 years, I dedicated my free time to satellite reception. I started with analogue satellite receptions, went over to digital reception, at some point got my first DiSEqC motor and so on.

I got me certified with an amateur radio license.

But my true passion started when a friend lend me a Satlook Digital NIT! I was fascinated with the real-time spectrum.

I started to save up money for such a field meter, but God, they were expensive and it was just for private hobby use. But I had an idea: because I am fluent in several languages, I wrote an email message offering user guide translations to every field meter manufacturer in the world.

None replied.

So I purchased the Emitor Satlook Digital NIT.

And then, out of the blue, I got a translation request from a well-known field meter manufacturer!

I did the translation, fast and at great price… And a great relationship was born. Naturally my initial plan got real and after some firmware strings translations, I received the first professional field meter to make translations easier.

Over the years I wrote many translations and even wrote manuals from scratch.

Later on I started to work with TELE-satellite, now called TELE-audiovision. This gave me many more challenges and test-equipment, too (I probably own the world’s largest TV, CATV & SAT field meter collection).

Note that all this work was done as a hobby in my free time, apart from my two regular jobs! Eventually I did make some money with it, but not much and most of the income was invested in more equipment.

And this year, I decided to dive deeper into the spectrum analysis.

So what did I do?

I purchased a Siglent SSA3021X spectrum analyser (1449 Euro), to basically learn how to work with a spectrum analyser. Some may say I am crazy, but in my opinion, it is cheaper to buy such an equipment for learning purposes, than taking some dull course. Also, I always wanted to own one and that’s cheaper than owning a KTM cross bike, to name an example.

Then I purchased two SMA Simple Spectrum Analyser devices. Why two? Easy: I broke the first one after two days. Meanwhile I repaired it by replacing the M810 IC using a hot air solder station (which I bought to learn more about SMD repairs).

Then I spend like 6 months writing the software to its current state.

Did I mention that during this period I bought other stuff, related to all of this:

• SMA Noise Source PCB (partially damaged due to stupid short cause by cable lying on my desk)
• SMA Noise Source second version in aluminium case
• DC Blocker
• SMA to F adapter
• SMA to SMA adapter
• N to F adapter
• N to BNC adapter
• Other adapter
• Cables
• Attenuator
• Switchable attenuator
• …

Two weeks ago I bought a Rigol DS1054Z oscilloscope to learn how to use a modern digital oscilloscope, but in preparation of a possible LNB power module with H/V, Low/High and DiSEqC control, also.

I ordered two sample Texas Instruments modules for that purpose (50 Euro, each), but run into some problems with Texas Instruments.

And today I got myself a cheap desktop 24MHz programmable signal generator.

I say all of this, to let you know how much I invested in stuff to acquire the required knowledge which enables me to write a program like this one. For me it was not something I wrote in a few hours – I had to learn a lot!

So this is why it means a lot to me, that you guys appreciate my software. It is a recognition that in the end the efforts paid off! And really, I don’t care so much about the donations. They won’t pay my bills. But they will help me buy some further equipment, which otherwise I couldn’t justify. Like why should I purchase the 35MHz-4.4GHz version? Or the NWT4000? The only reason is to better support them. Myself, I don’t need them – I have a REAL spectrum analyser on my desk, capable of doing 9 kHz up to 3.1 GHz…

Sorry for the long post!

BTW: I started writing a user guide, but it will take much longer than I imagined. I forgot how many functions there are now. Also, there are some tricks, which seem obvious to me, but apparently, people did not realize it.

Example: why does the shaded spectrum look fine at 500 samples, but has just a few vertical lines when using 100 samples?

Because these lines represent the exact samples!

If you use 1000 samples, the live trace will be totally green in shaded mode, because the screen has a horizontal resolution of 1000 pixels, so each pixel column has exactly one line.

With 500 samples, the software draws every odd line. But because of anti-aliasing activated on purpose, the shaded area is a darker semi-transparent green. This is nice if more than one trace is being drawn, as the colours of the different traces will blend.

At lesser samples, you start to see the lines, which is nice, because you can exactly see which points have been measured!

The curve itself is not just straight connections – it is a best-fit polynomial curve of the sampled points.

All of this will result in a much better resolution than most TV/SAT field meter!

Regards,
vma

 

[John]

Hi,

I will accept donations (10€, 10£, 10US$ - whichever is more convenient and cheaper) through my PayPal account. I have informed myself and there is no worries, as long as I don't make a business out of it, which I won't... So far I have given out around 20 activation codes - so you guys get an idea of the business dimensions!

Anyway, I want to make the following very clear:

1. I am giving out free codes and intend to continue doing so. To make things easier for me, these free codes will terminate on the last day of March, June, September or December - you always get activation codes for the next deadline.
2. You may request as many renewals as you want.
3. You may request several codes for your main PC, laptop, tablet, etc.
4. Donations are NOT mandatory at all, they will not give any extra functionality - but I will return the good-will with a permanent activation code for your main PC, laptop, tablet, etc.
5. Donations will NOT entitle to any special support or feature request - all functionality can be extensively tested with free activation codes and new functionality is implemented according to my ideas, people's suggestions, feasibility, etc.
6. Donations will help me paying for additional devices, so I can possibly enhance the functionality of the software and better support devices, which I currently don't own.

Donation instructions will be included in future releases, but basically consist of these lines and the required e-mail address of my PayPal account.

I do appreciate some of you being eager to make a donation - it means a lot more to me than the simple value of the donation itself.

I will explain:

I am a metallurgical and materials science engineer and I work with CAD/CAM/CAE systems. I have no formal education on RF, broadcasting, signal distribution, etc.

However, in the last 20 years, I dedicated my free time to satellite reception. I started with analogue satellite receptions, went over to digital reception, at some point got my first DiSEqC motor and so on.

I got me certified with an amateur radio license.

But my true passion started when a friend lend me a Satlook Digital NIT! I was fascinated with the real-time spectrum.

I started to save up money for such a field meter, but God, they were expensive and it was just for private hobby use. But I had an idea: because I am fluent in several languages, I wrote an email message offering user guide translations to every field meter manufacturer in the world.

None replied.

So I purchased the Emitor Satlook Digital NIT.

And then, out of the blue, I got a translation request from a well-known field meter manufacturer!

I did the translation, fast and at great price… And a great relationship was born. Naturally my initial plan got real and after some firmware strings translations, I received the first professional field meter to make translations easier.

Over the years I wrote many translations and even wrote manuals from scratch.

Later on I started to work with TELE-satellite, now called TELE-audiovision. This gave me many more challenges and test-equipment, too (I probably own the world’s largest TV, CATV & SAT field meter collection).

Note that all this work was done as a hobby in my free time, apart from my two regular jobs! Eventually I did make some money with it, but not much and most of the income was invested in more equipment.

And this year, I decided to dive deeper into the spectrum analysis.

So what did I do?

I purchased a Siglent SSA3021X spectrum analyser (1449 Euro), to basically learn how to work with a spectrum analyser. Some may say I am crazy, but in my opinion, it is cheaper to buy such an equipment for learning purposes, than taking some dull course. Also, I always wanted to own one and that’s cheaper than owning a KTM cross bike, to name an example.

Then I purchased two SMA Simple Spectrum Analyser devices. Why two? Easy: I broke the first one after two days. Meanwhile I repaired it by replacing the M810 IC using a hot air solder station (which I bought to learn more about SMD repairs).

Then I spend like 6 months writing the software to its current state.

Did I mention that during this period I bought other stuff, related to all of this:

• SMA Noise Source PCB (partially damaged due to stupid short cause by cable lying on my desk)
• SMA Noise Source second version in aluminium case
• DC Blocker
• SMA to F adapter
• SMA to SMA adapter
• N to F adapter
• N to BNC adapter
• Other adapter
• Cables
• Attenuator
• Switchable attenuator
• …

Two weeks ago I bought a Rigol DS1054Z oscilloscope to learn how to use a modern digital oscilloscope, but in preparation of a possible LNB power module with H/V, Low/High and DiSEqC control, also.

I ordered two sample Texas Instruments modules for that purpose (50 Euro, each), but run into some problems with Texas Instruments.

And today I got myself a cheap desktop 24MHz programmable signal generator.

I say all of this, to let you know how much I invested in stuff to acquire the required knowledge which enables me to write a program like this one. For me it was not something I wrote in a few hours – I had to learn a lot!

So this is why it means a lot to me, that you guys appreciate my software. It is a recognition that in the end the efforts paid off! And really, I don’t care so much about the donations. They won’t pay my bills. But they will help me buy some further equipment, which otherwise I couldn’t justify. Like why should I purchase the 35MHz-4.4GHz version? Or the NWT4000? The only reason is to better support them. Myself, I don’t need them – I have a REAL spectrum analyser on my desk, capable of doing 9 kHz up to 3.1 GHz…

Sorry for the long post!

BTW: I started writing a user guide, but it will take much longer than I imagined. I forgot how many functions there are now. Also, there are some tricks, which seem obvious to me, but apparently, people did not realize it.

Example: why does the shaded spectrum look fine at 500 samples, but has just a few vertical lines when using 100 samples?

Because these lines represent the exact samples!

If you use 1000 samples, the live trace will be totally green in shaded mode, because the screen has a horizontal resolution of 1000 pixels, so each pixel column has exactly one line.

With 500 samples, the software draws every odd line. But because of anti-aliasing activated on purpose, the shaded area is a darker semi-transparent green. This is nice if more than one trace is being drawn, as the colours of the different traces will blend.

At lesser samples, you start to see the lines, which is nice, because you can exactly see which points have been measured!

The curve itself is not just straight connections – it is a best-fit polynomial curve of the sampled points.

All of this will result in a much better resolution than most TV/SAT field meter!

Regards,
vma

Vitor, i am more than happy to accept your donation outlines. Thank you for a very useful addition to my hobby.

 

[jeallen01]

vma

I really do appreciate your "dedication to the cause" and will, willingly, give my £10 when we know how to do that - and so, the sooner the better!

Others will, I am sure, will do the same.

Go forth and "conquer" !

PS: will be very interested in seeing what you can do with the 35MHz-4.4 GHz version of the dongle because some of my areas interest are at the lowest end of that frequency range.

PPS: one way to facilitate us sending you the money might be to ask them to start a Conversation in which you could provide the info without making it very public.

 

[scopus]

Same here, more than willing to donate £10 and accept the conditions
Great piece of sw and enables to keep the spectrum on all the time instead of my satlook NIT which would suffer screen burn being on all the time being a CRT screen.

 

[vma]

"PS: will be very interested in seeing what you can do with the 35MHz-4.4 GHz version of the dongle because some of my areas interest are at the lowest end of that frequency range."

Actually I *think* that this device (and the NWT4000-2 model, both using the ADF4351 instead of the ADF4350) is already fully supported!
If you go to the setup tab, you can select ADF4351 and that should do the trick.

The thing is, I have not tried it myself, due to the fact that I don't own an ADF4351 model and because nobody owning one gave me feedback so far.

With the NWT4000, there is potential for some new developments, as this device has actually two ADF4350/ADF4351 IC's. It is capable of simultaneously input and output RF signals. I would love implementing a tracking generator...

Regards,
vma

 

[jeallen01]

vma

Not sure if the following counts as a small "glitch",:

Just rejigged the whole physical layout of my small ACER system and plugged the S/A unit lead into a different (USB2) port, whereas it had previously been plugged into a USB3 port - and then the s/w would open but would not START the scan and I got a "Com Port 3 unavailable" type of message.

Had to re-extract the s/w from the ZIP file (to the same disk location) and over-write the previously-installed executable (both the same version) before it would START the scan and display the spectrum with the S/A unit connected to a USB2 port again.

Two possible thoughts:
- Does the s/w look for the 1st USB port into which the USB lead is plugged when first installed and activated, and does not then work properly if you moved that lead to another port (unless you do what I just did)?
- OTOH could it be due to the differences between USB2 & USB3 ports because I , for access reasons, then moved the USB lead to another USB2 port and there was no similar problem?

 

[vma]

Hi,

The software simply requests the list of COM ports and puts it into a combo box in the settings tab.
The user then selects the relevant COM port and this selection is stored in the registry.
Because the software does not establish any connection upon start, you can always go to the setup tab and change the COM setting.

My guess is that your problems are due to FTDI driver issues!

I can attach my device into any COM port wothout problem. Interestingly, if I attach my second unit, it will always be assigned COM4, while the first device is assigned COM3.

Regards,
vma

 

[jeallen01]

vma

Thanks for the explanation

When I looked in Settings the selected Com Port was blank, but when I clicked on the selection box it shows a choice of either 1 or 3 - and, since I never did actually select a Com port previously, then I assume the s/w chooses "whichever works" on the first occasion that it is run, and you then have to change it manually later if you change USB ports as I did

 

[jeallen01]

vma

Something else: is there any way you could include the normal "-" "[]" & "X" options boxes on the display so that it could be either minimised, resized OR Closed?

At the moment it occupies a quite large fixed area on a PC screen and that cannot be changed, and so the only option if you need "some of that space" is to Close the programme - so it would be very useful to be able to resize it so that the running window occupies less screen area.