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

[vma]

Another thing, I just realized... You can actually record a few minutes of the spectrum and upload the file. The satellite identification works in play mode, too. This way I can check the algorithm without having C band myself.

How cool I that?

 

[John]

Try setting amplitude so that the transponders get "higher".
Increase the Min. Bandwidth to 10-15 MHz.

... Will do

 

[John]

Also, My software ignores transponders in the *.ini files with an SR less than 7000. Maybe I have to change that.
Regards,
Vitor

... Agree Vitor, Re: C-band, there are quite a lot of channels on transponders with SR's less than 7000 used on quite a few different satellites. If your software is omitting these then the satellite identification task would be a lot harder

 

[vma]

Hi,

Uploaded a new version:

2016-12-18: User configurable SR treshold for Ku- and C-Band Satellite Identification in Setup Tab

My request:

Please upload pictures and full spectrum recording of a C-Band satellite! Let the recording run for 1-2 minutes and then upload as a zipped archive. Should be relatively small.

This is nice for people who want to experiment and/or see the spectrum of different satellites. One can memorize how different satellites "look" like. It's nice for documentation of strange/new/intermittent signals.

Hopefully, in people start sharing the spectrum recording instead of just a spectrum picture.

Regards,
Vitor

 

[vma]

Just noticed a bug: if playing back a recorded spectrum log, the satellite ID does not work. I will fix that ASAP.

 

[vma]

New version uploaded:

2016-12-18:
- User configurable SR treshold for Ku- and C-Band Satellite Identification in Setup Tab
- Fixed bug: Satellite Identification was not working when playing back recorded spectrum log
- Grid lines are drawn with dashed lines, improving readability

Attached is a recorded spectrum: the dish goes from 28.2E continously to 30.0W and then back again. Next I move from 28.2E to different satellites, holding on each for a moment, up to 30.0W. The last bit shows me driving to 0.8W and from there manually searching for Atlantic Bird 8.0W, which my receiver somehow messed up. With the satellite identification it is really easy to program motor positions!

It is amazing, how small such a spectrum recording gets, when zipped (and even uncompressed it is just 1.49 Megabyte. It contains around 8 minutes of live spectrum.

Regards,
Vitor

 

[John]

New version uploaded:

2016-12-18:
- User configurable SR treshold for Ku- and C-Band Satellite Identification in Setup Tab
- Fixed bug: Satellite Identification was not working when playing back recorded spectrum log
- Grid lines are drawn with dashed lines, improving readability

Attached is a recorded spectrum: the dish goes from 28.2E continously to 30.0W and then back again. Next I move from 28.2E to different satellites, holding on each for a moment, up to 30.0W. The last bit shows me driving to 0.8W and from there manually searching for Atlantic Bird 8.0W, which my receiver somehow messed up. With the satellite identification it is really easy to program motor positions!

It is amazing, how small such a spectrum recording gets, when zipped (and even uncompressed it is just 1.49 Megabyte. It contains around 8 minutes of live spectrum.

Regards,
Vitor

... still no joy i'm afraid on C-band sat recognition after trying various permutations & different birds, and once i figure out how to up-load the .sar file recording i will

 

[vma]

Just record the live spectrum while you are playing with the different functions (doesn't impact the recording). The resulting file can be zipped and uploaded here as an attachment.

This would allow me (and others) to see your C-Band spectrum and apply whatever measurements or tools of the software, while in play back mode. Actually, the software offers the same functions in play back mode, as if you were looking at a live spectrum - you can identify transponders/satellites, create single frequency logs, play with the amplitude settings, traces, etc. You just cannot change the start/stop-frequency or the span.

I don't really have much experience with C-Band apart from a few trials, so I don't know how the spectrum looks like and how easy it is to identify the transponders and match them against the satellite transponder lists of the *.ini files. Also, I guess that C-Band transponders often use a very low SR (aka small bandwidth), which makes it difficult to distinguish poorly received transponders from those that have a small bandwidth.

Another tip: the satellite identification allows any span. You can zoom into the few transponders that matter. This will cause rendering of them in higher resolution (= lower RBW), making transponder recognition more precise.

Regards,
Vitor

 

[John]

... still no joy i'm afraid on C-band sat recognition after trying various permutations & different birds, and once i figure out how to up-load the .sar file recording i will

..... hopefully this will show the recorded file, it really needs re-naming to 55°West Hor. Intelsat 34.

 

[vma]

Thanks for the file.

The satellite recognition doesn't work for the following reasons:

1) The *.ini files installed by default only go up to 40.0W, so you need to copy the relevant *.ini files inside the transponder_lists folder.
2) The example 3045.ini file I got is incomplete and wrong. i suspect it has not been updated for a while.
3) The reception quality is very fragile for satellite identification and this particular satellite only offers 3-4 really good transponders.

All this makes it hard for the algorithm.

However, there is sometinh obvious, which I didn't think of, before: my algorithm should take the LOF into account, to include/exclude satellites in Ku/C band, accordingly. Example: if LOF is unset, ALL satellite bands should be considered. If set to >=9750 then only Ku bands should be considered and if set to <9750 then only C-band bands should be considered. This way, false matches could be avoided between Ku and C band.

Going to think about this.

Regards,
Vitor

 

[vma]

@John: Again, thanks for your file! It helped me to find a few bugs related to C-Band Satellite Identification. The good news is that your file is now correctly recognized!

@all: New version uploaded.

Please note that the included *.ini files are basically matching my reception preferences/capabilities. If you need to receive more/different satellites, you need to update the "transponder_lists" folder with the relevant *.ini files!

Hopefully, this example shows how useful it is to be able to record and reply a live spectrum session!

Regards,
Vitor

 

[John]

New version uploaded:

2016-12-18:
- User configurable SR treshold for Ku- and C-Band Satellite Identification in Setup Tab
- Fixed bug: Satellite Identification was not working when playing back recorded spectrum log
- Grid lines are drawn with dashed lines, improving readability

Attached is a recorded spectrum: the dish goes from 28.2E continously to 30.0W and then back again. Next I move from 28.2E to different satellites, holding on each for a moment, up to 30.0W. The last bit shows me driving to 0.8W and from there manually searching for Atlantic Bird 8.0W, which my receiver somehow messed up. With the satellite identification it is really easy to program motor positions!

It is amazing, how small such a spectrum recording gets, when zipped (and even uncompressed it is just 1.49 Megabyte. It contains around 8 minutes of live spectrum.

Regards,
Vitor

Agree on the dashed grids, another nice touch.

Can i put a request in Vitor if possible, anybody like me who is possibly using a small screen, say a 10" tablet, and is getting on a bit in age tend to struggle with small text. It would be better for me if the frequency read-outs along the bottom of the spectrum plot could be bigger and also the text in the "Spectrum Pre-sets & Parameters" box,s ....So, would it be possible to do a custom version for us old timers even if it means loosing some of the more recent update features ?.
Regards.

 

[vma]

The GUI has been a constant struggle, because I wanted to dedicate so much screen space for the spectrum itself (1000x500 + 1000x100).

There seem to be users using the software for very different things: some like to use it for satellite stuff (integer MHz is OK), others i.e. for amateur radio applications or filter testing (need KHz resolution). I do my best to please you all, but I reached the limit regarding screen area!

The easiest would really be to assume everyone has a FullHD screen (1920x1080) and then I could increase the size of the window and with that the size of the font on all controls. This is how the software started: I just used my screen resolution and never thought that people might end up using the software and on top of that, it didn't even occur to me that people might use PC's with less screen resolution! I am fortunate to have a company laptop with FullHD, my home PC is FullHD (three screens, actually) and even my Windows tablet has 2560x1600 resolution. But due to many requests I settled with 1280x780 resolution, the missing 20 vertical pixel lines being reserved for the taskbar. So no change to happen here.

I did recently decrease the font size inside the graphics area (frequency and dB values), to compensate for the extra 3 decimal digits - otherwise the end of the first frequency value would bump into the start of the next one. I didn't exepect anyone to notice!

What I could do is to increase the font size of the grid related text, IF you deselect the now default setting of displaying frequencies with 3 decimal places. I could add that setting to the registry, so it gets stored and retrieved upon start.

Another thing I could do is to add a "tool tip" function, where hovering the mouse over a relevant control would show its contents in an info-window with bigger text. Not perfect, but would allow easy reading.

Would that help?

Regards,
Vitor

 

[John]

The GUI has been a constant struggle, because I wanted to dedicate so much screen space for the spectrum itself (1000x500 + 1000x100).

There seem to be users using the software for very different things: some like to use it for satellite stuff (integer MHz is OK), others i.e. for amateur radio applications or filter testing (need KHz resolution). I do my best to please you all, but I reached the limit regarding screen area!

The easiest would really be to assume everyone has a FullHD screen (1920x1080) and then I could increase the size of the window and with that the size of the font on all controls. This is how the software started: I just used my screen resolution and never thought that people might end up using the software and on top of that, it didn't even occur to me that people might use PC's with less screen resolution! I am fortunate to have a company laptop with FullHD, my home PC is FullHD (three screens, actually) and even my Windows tablet has 2560x1600 resolution. But due to many requests I settled with 1280x780 resolution, the missing 20 vertical pixel lines being reserved for the taskbar. So no change to happen here.

I did recently decrease the font size inside the graphics area (frequency and dB values), to compensate for the extra 3 decimal digits - otherwise the end of the first frequency value would bump into the start of the next one. I didn't exepect anyone to notice!

What I could do is to increase the font size of the grid related text, IF you deselect the now default setting of displaying frequencies with 3 decimal places. I could add that setting to the registry, so it gets stored and retrieved upon start.

Another thing I could do is to add a "tool tip" function, where hovering the mouse over a relevant control would show its contents in an info-window with bigger text. Not perfect, but would allow easy reading.

Would that help?

Regards,
Vitor

Thanks for understanding, how i use the software i could easily go to two or even one decimal place Vitor, the "Tool Tip" idea also sounds good and would love to try it.
Regards.

 

[vma]

Just uploaded new version:

2016-12-20:
- Decimal places setting now stored in registry
- If decimal places switched off, frequencies are rendered in bigger font
- Tooltips shown for better readability on frequency settings and presets

Regards,
Vitor

 

[John]

Todays scan ....
40.5º West Cband LHC instantly recognised with sat ident function.

Noted: ---- I found that if the "Threshold" setting is seeing the noise floor then this stops the sat ID from responding.

Recording of .sal file below

 

[vma]

"Noted: ---- I found that if the "Threshold" setting is seeing the noise floor then this stops the sat ID from responding."

Yes. That is exactly how it works! The treshold looks at the average power level multiplied by the user defined percentage, which allows to adjust it. The orange line must clearly intersect the relevant transponders.

With bad polarisation configuration, where you see transponders of the opposite polarisation creeping up in the spectrum, you don't want the horizontal treshold line to cross these transponders.

I think the satellite identification routine is now free from errors and should be working fine in Ku- and C-band.

Thanks for uploading the picture!

Regards,
Vitor

PS: I see you are using the latest version with the big fonts if three decimal places are switched off.

 

[John]

"Noted: ---- I found that if the "Threshold" setting is seeing the noise floor then this stops the sat ID from responding."

Yes. That is exactly how it works! The treshold looks at the average power level multiplied by the user defined percentage, which allows to adjust it. The orange line must clearly intersect the relevant transponders.

With bad polarisation configuration, where you see transponders of the opposite polarisation creeping up in the spectrum, you don't want the horizontal treshold line to cross these transponders.

I think the satellite identification routine is now free from errors and should be working fine in Ku- and C-band.

Thanks for uploading the picture!

Regards,
Vitor





>>PS: I see you are using the latest version with the big fonts if three decimal places are switched off.

<<
... Yes i am, thank you for the quick up-grade response ;)

 

[scopus]

Same for me, instantly picked up 40W C band with the new version.
A request please Vitor, could the box 'mouse position' be made into bigger font? That would be very nice for people with a smaller screen, make it easier to see what frequency you are at.

 

[jeallen01]

I know many of us have already thanked/"liked" Vitor in individual posts for all his very hard work on the SSA s/w, but how about a collective "Thank You" from all of us for making such an inexpensive item so useful and valuable!
(and have you donated yet?)