Feedback for version 1.0a here

Information and discussions on Spectrum Analysis
SteveAndrew
Posts: 213
Joined: Thu Nov 16, 2017 11:06 pm
Location: Gold Coast, QLD, Australia

Re: Feedback for version 1.0a here

Post by SteveAndrew » Sun Apr 07, 2019 3:54 am

ja8scd wrote:Hi Steve,

I mean such a function by which the white trace becomes flat (0dB - reference line) so the yellow trace will be displayed in relative to the white one. This is because noise generators will not give out uniform output from 1kHz to 2GHz, and also we don't need absolute dBm readings when it comes to measuring filters.

73,

Yas - JA8SCD Tokyo
Hi Yas

Understood, thank you.

I did have some thoughts in that direction when the original analyser but were dropped for various reasons. What I had considered was adding a trace-maths function so that the difference between two traces could be plotted with it's own scaling. I think that would do what you are asking without the need for a normalisation or calibration run. I think it would be a useful feature, and something worth considering - No promises that it will make it into V1.0 though.

Steve

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briansmithers1701
Posts: 1
Joined: Sat Mar 30, 2019 10:33 pm

Re: Feedback for version 1.0a here

Post by briansmithers1701 » Tue Apr 09, 2019 6:58 am

I'm just getting to grips with this software and thanks for making it available.
A little feedback....

I have my SDR Play built into an old radio chassis with a nice switched attenuator built in. There's also room left for the tracking generator (next thing to build) and a wide band noise generator module - currently on the way from China.

My workshop computer is one of those not very powerful small format units that screw on the back of the screen. It is running Windows 10.

I see in the release notes that under item "2" you are aware of the screen intermittently freezing. Mine does that but only when the sweep is wide - like 10MHz or more. At the lower sweep settings it runs OK. I imagine that many people will be running a PC better than mine so hopefully this data is of some use to Andrew. If it is happening on many other (faster) computers then it probably isn't processor speed related (or is it!).

Another observation made yesterday was that when looking at an injected signal - which as I steadily increase, the displayed amplitude stops increasing at some point as I reduce the manual attenuator that I fitted. Some kind of "AGC" I suspect - but when it starts to do that I assume that the message is to not increase it any more or some smoke might escape from the SDR Play unit.

There is a very neat and inexpensive switched attenuator recently appeared on a blog that I follow which may interest forum members...
http://kv4qb.blogspot.com/2019/04/63-db ... uator.html

Regards
Brian
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SteveAndrew
Posts: 213
Joined: Thu Nov 16, 2017 11:06 pm
Location: Gold Coast, QLD, Australia

Re: Feedback for version 1.0a here

Post by SteveAndrew » Tue Apr 09, 2019 8:43 am

Hi Brian
briansmithers1701 wrote: I see in the release notes that under item "2" you are aware of the screen intermittently freezing. Mine does that but only when the sweep is wide - like 10MHz or more. At the lower sweep settings it runs OK. I imagine that many people will be running a PC better than mine so hopefully this data is of some use to Andrew. If it is happening on many other (faster) computers then it probably isn't processor speed related (or is it!).
The freezing problem is a bug and will happen on any computer irrespective of speed. The problem has now been fixed.
briansmithers1701 wrote: Another observation made yesterday was that when looking at an injected signal - which as I steadily increase, the displayed amplitude stops increasing at some point as I reduce the manual attenuator that I fitted. Some kind of "AGC" I suspect - but when it starts to do that I assume that the message is to not increase it any more or some smoke might escape from the SDR Play unit.
There is no AGC. The reference level sets the level at the top of the display, as well as controlling the LNA and IF gain settings. If the signal is getting close to the reference level, then it might be time to select a higher reference level. The reference level has no control over the unit's smoke-emission control system. The maximum input to an RSP unit is +10dBm, for short periods, otherwise, 0dBm is considered to be safe for continuous levels.

Steve

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PeterW
Posts: 8
Joined: Sat Apr 06, 2019 7:08 am

Re: Feedback for version 1.0a here

Post by PeterW » Tue Apr 09, 2019 6:59 pm

On some old "or newer" HP Spectrum analyzers I remembered that if I put in "zero" span or something you could listen to the signal in a built in AM/FM detector, could that be some feature to add in future ?

//Peter
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SteveAndrew
Posts: 213
Joined: Thu Nov 16, 2017 11:06 pm
Location: Gold Coast, QLD, Australia

Re: Feedback for version 1.0a here

Post by SteveAndrew » Thu Apr 11, 2019 7:46 am

PeterW wrote:On some old "or newer" HP Spectrum analyzers I remembered that if I put in "zero" span or something you could listen to the signal in a built in AM/FM detector, could that be some feature to add in future ?

//Peter
Hi Peter

It's on the list of things to think about, and will eventually happen. I can't give you a timeline at this point.

Steve

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yesitsdrew5310
Posts: 2
Joined: Fri Apr 12, 2019 8:47 pm

Re: Feedback for version 1.0a here

Post by yesitsdrew5310 » Fri Apr 12, 2019 8:58 pm

Thank you so much for your time on this program Steve! I would really love the ability to export a .csv file with the MHz and dBm readings from the scan. This would make this a very useful tool in the Professional Audio arena as an RF Spectrum Analyzer to import this file directly into the tool we use to calculate IMD and available frequencies for programming our wireless microphones.

The dream for me would be to have a .csv file that had the frequency in MHz in one column and the dBm measurement in the next.

In a text editor the .csv would read:
240.000, -95.0
240.252, -105.0
240.504, -98.0
240.757, -103.0

and then continue to the last frequency sampled.

Is an addition to the program like this possible? Thanks!
--Drew
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SteveAndrew
Posts: 213
Joined: Thu Nov 16, 2017 11:06 pm
Location: Gold Coast, QLD, Australia

Re: Feedback for version 1.0a here

Post by SteveAndrew » Mon Apr 15, 2019 12:40 am

yesitsdrew5310 wrote:I would really love the ability to export a .csv file with the MHz and dBm readings from the scan. This would make this a very useful tool in the Professional Audio arena as an RF Spectrum Analyzer to import this file directly into the tool we use to calculate IMD and available frequencies for programming our wireless microphones.

The dream for me would be to have a .csv file that had the frequency in MHz in one column and the dBm measurement in the next.

In a text editor the .csv would read:
240.000, -95.0
240.252, -105.0
240.504, -98.0
240.757, -103.0

and then continue to the last frequency sampled.

Is an addition to the program like this possible? Thanks!
--Drew
Hi Drew

Data export is on the future developments list and will include data in CSV format. I can't give you any sort of timeline at the moment, but it will probably make the cut along with other additions in the next update.

Steve

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yesitsdrew5310
Posts: 2
Joined: Fri Apr 12, 2019 8:47 pm

Re: Feedback for version 1.0a here

Post by yesitsdrew5310 » Mon Apr 15, 2019 12:42 am

That is great! Thanks so much!
--Drew
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Brian VK6LO
Posts: 8
Joined: Tue Jan 29, 2019 11:51 pm

Re: Feedback for version 1.0a here

Post by Brian VK6LO » Mon Apr 15, 2019 9:48 am

I have indications that Tuner selection on the DUO is 'flaky'

1. Operating with signal input to Tuner 2 displayed then stop the program with Tuner 2 still selected and close the program

2. Restart the analyser and Tuner 1 is now highlighted but the signal from Tuner 2 connection is displayed - select Tuner 2 = no signal displayed

3. Reselect Tuner 1 and signal from tuner 2 displays then select HighZ and signal disappears (correct)
With input still on tuner 2 select 2 and signal may or may not be displayed

It seems that initial program start highlites tuner 1 in the program but does not select tuner 1 in the radio and from then on various combinations of tuner selection may or may not happen correctly

Brian

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glovisol
Posts: 662
Joined: Thu May 10, 2018 6:42 pm
Location: Piedmont, Italy

Re: Feedback for version 1.0a here

Post by glovisol » Tue Apr 16, 2019 5:51 pm

Hi Steve,

There is a "false start" problem whereby on switch on of a measurement previoulsly set up and OK the Spectrum Analyser comes up wrong, like if it was overloaded. Then, by altering the REF level and going back the SA recovers, as shown in the enclodes pics. Otherwise I have been working for several days with this 1.0a software and it is really a dream!

Kind regards,

Gianfranco
Attachments
SA False Start 1.jpg
SA False Start 1.jpg (253.93 KiB) Viewed 5615 times
SA False Start 2.jpg
SA False Start 2.jpg (256.59 KiB) Viewed 5615 times
SA False Start 3.jpg
SA False Start 3.jpg (251.43 KiB) Viewed 5615 times

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