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Would it be wonderful if there would be, next to the nanoVNA, a nanoSA or nano Spectrum Analyzer?
Well I decided to test what the most simple SA could look like, just good enough to test the harmonics level of your signals till 400MHz and some other, not too complex, measurements.
According to my estimate the BOM of the nanoSA on the photo would be around 12$
Main components are two SI4432 modules, one in RX mode at 443MHz using the RSSI as log detector, one as +20dBm LO for the mixer (443MHz - 886MHz), a 443mHz SAW filter as first IF filter, a Double balanced diode mixer and an arduino zero (3.3 volt) or compatible (arduino micro with 3.3v serial to USB module will also work), adding a LCD will still keep the cost below 25$ or 50$ retail.
The measurement performance is surprisingly useful.
Attached a scan of the harmonics and spurs of a SI5351 at 25MHz
And a scan of the AD9851 ast 25MHz, both connected through a 30dB attenuator
Specs:
Range 0-400MHz (0-200MHz with unmodified modules)
RBW selectable between 3kHz and 600kHz
With RWB=300kHz noise floor below -90dBm
Max signal around -5dBm
Did not yet do the IIP3 measurement but the used ADE-25MH is supposed to be +13dBm
Good enough for many measurements.
Things to further improve:
- 400MHz low pass filter at input
- remove output filter of TX module to get full 400MHz bandwidth
- Put everything in a box.
I hope someone gets inspired and puts everything on a PCB with a LCD as a small standalone SA (nanoSA)
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If calibrated for amplitude at spot frequencies using nanoVNA,
then could some SDR (e.g. SDRplay has Android API) be useful for spectrum analyses?
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On Tue, Oct 8, 2019 at 08:51 AM, <erik@...> wrote:
Would it be wonderful if there would be, next to the nanoVNA, a nanoSA or nano
Spectrum Analyzer?
Well I decided to test what the most simple SA could look like, just good
enough to test the harmonics level of your signals till 400MHz and some other,
not too complex, measurements.
Thanks for playing with this idea, Erik. There was a comment from a Japanese NanoVNA user on Twitter comparing the use of the Nano to an oscilloscope that is in the same price range but has poor specs. They gave an example of JYE Tech's 200KHz bandwidth scope kit for $30 vs the Nano's capabilities - image attached. At this time, there is not near enough memory to implement a scope function - maybe in the version 2 device?
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Dr. David Kirkby from Kirkby Microwave Ltd
On Tue, 8 Oct 2019 at 13:51, <erik@...> wrote: Would it be wonderful if there would be, next to the nanoVNA, a nanoSA or
nano Spectrum Analyzer?
Well I decided to test what the most simple SA could look like, just good
enough to test the harmonics level of your signals till 400MHz and some
other, not too complex, measurements.
According to my estimate the BOM of the nanoSA on the photo would be
around 12$ Yes, it would be very useful. But could one go further and combine the SA & VNA into one unit? For what it is worth, Keysight sell a range of portable FieldFox instruments. They are either * Spectrum analyzers * Vector Network analyzers * Combination analyzers with the latter having SA & VNA capabilities.
I hope someone gets inspired and puts everything on a PCB with a LCD as a
small standalone SA (nanoSA)
Or NanoCA - combination analyzer??????? Dave -- Dr. David Kirkby, Kirkby Microwave Ltd, drkirkby@... Telephone 01621-680100./ +44 1621 680100 Registered in England & Wales, company number 08914892. Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United Kingdom
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If I can say a little something about this Idea.
A tracking generator would not cost a lot more in ressources and would
be a nice addon in a NanoSa.
And the possibility to add an amplifier to the TG to bring the level
to 30 DBm (1watt) would also be cool.
And lastly with the Generator in the TG, if you can modulate the
signal with a tone at a deviation level you can set, we could do some
really nice stuff.
With that said, I have a nice pelican box that could house all of
those nice device with a large rechargeable bank of Lithium/ion
battery lots of cable and adaptors. A Raspberry Pi4, 2 hdmi touche
screen And we have a portable RF labs..
toggle quoted message
Show quoted text
Le mar. 8 oct. 2019 ¨¤ 09:18, Larry Rothman <nlroth@...> a ¨¦crit :
On Tue, Oct 8, 2019 at 08:51 AM, <erik@...> wrote:
Would it be wonderful if there would be, next to the nanoVNA, a nanoSA or nano
Spectrum Analyzer?
Well I decided to test what the most simple SA could look like, just good
enough to test the harmonics level of your signals till 400MHz and some other,
not too complex, measurements.
Thanks for playing with this idea, Erik.
There was a comment from a Japanese NanoVNA user on Twitter comparing the use of the Nano to an oscilloscope that is in the same price range but has poor specs.
They gave an example of JYE Tech's 200KHz bandwidth scope kit for $30 vs the Nano's capabilities - image attached.
At this time, there is not near enough memory to implement a scope function - maybe in the version 2 device?
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On Tue, Oct 8, 2019 at 07:01 AM, Dr. David Kirkby from Kirkby Microwave Ltd wrote:
* Combination analyzers
with the latter having SA & VNA capabilities.
Been there. done that. This is my combined 3GHz VNA and 2GHz SA with TG Problem with this setup is the minimum VNA frequency of 35MHz due to the re-use of the two ADF4351 modules. The nanoVNA solves that problem. But this CA is neither nano or cheap. Having a generator that can go both high and low in frequency is expensive.
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To the extent that this encourages present or future developers out there:
A spectrum analyzer, with a tracking generator, that covers "below HF"
through "above UHF", with user-selectable RBW and VBW, for around 50 USD
would be ... awesome!
[FWIW, I'm "blown away" by the nanoVNA ... so my thanks to those
developers.]
Paul
WB1EMK
toggle quoted message
Show quoted text
On Tue, Oct 8, 2019, 10:02 Pierre Martel <petem001@...> wrote: If I can say a little something about this Idea.
A tracking generator would not cost a lot more in ressources and would
be a nice addon in a NanoSa.
And the possibility to add an amplifier to the TG to bring the level
to 30 DBm (1watt) would also be cool.
And lastly with the Generator in the TG, if you can modulate the
signal with a tone at a deviation level you can set, we could do some
really nice stuff.
With that said, I have a nice pelican box that could house all of
those nice device with a large rechargeable bank of Lithium/ion
battery lots of cable and adaptors. A Raspberry Pi4, 2 hdmi touche
screen And we have a portable RF labs..
Le mar. 8 oct. 2019 ¨¤ 09:18, Larry Rothman <nlroth@...> a ¨¦crit :
On Tue, Oct 8, 2019 at 08:51 AM, <erik@...> wrote:
Would it be wonderful if there would be, next to the nanoVNA, a nanoSA
or nano
Spectrum Analyzer?
Well I decided to test what the most simple SA could look like, just
good
enough to test the harmonics level of your signals till 400MHz and
some other,
not too complex, measurements. Thanks for playing with this idea, Erik.
There was a comment from a Japanese NanoVNA user on Twitter comparing
the use of the Nano to an oscilloscope that is in the same price range but
has poor specs.
They gave an example of JYE Tech's 200KHz bandwidth scope kit for $30 vs the Nano's capabilities - image attached.
At this time, there is not near enough memory to implement a scope function - maybe in the version 2 device?
|
Dr. David Kirkby from Kirkby Microwave Ltd
On Tue, 8 Oct 2019 at 15:02, Pierre Martel <petem001@...> wrote: If I can say a little something about this Idea.
A tracking generator would not cost a lot more in ressources and would
be a nice addon in a NanoSa.
And the possibility to add an amplifier to the TG to bring the level
to 30 DBm (1watt) would also be cool.
And lastly with the Generator in the TG, if you can modulate the
signal with a tone at a deviation level you can set, we could do some
really nice stuff.
With that said, I have a nice pelican box that could house all of
those nice device with a large rechargeable bank of Lithium/ion
battery lots of cable and adaptors. A Raspberry Pi4, 2 hdmi touche
screen And we have a portable RF labs..
Le mar. 8 oct. 2019 ¨¤ 09:18, Larry Rothman <nlroth@...> a ¨¦crit :
On Tue, Oct 8, 2019 at 08:51 AM, <erik@...> wrote:
Would it be wonderful if there would be, next to the nanoVNA, a nanoSA
or nano
Spectrum Analyzer?
Well I decided to test what the most simple SA could look like, just
good
enough to test the harmonics level of your signals till 400MHz and
some other,
not too complex, measurements. Thanks for playing with this idea, Erik.
There was a comment from a Japanese NanoVNA user on Twitter comparing
the use of the Nano to an oscilloscope that is in the same price range but
has poor specs.
They gave an example of JYE Tech's 200KHz bandwidth scope kit for $30 vs the Nano's capabilities - image attached.
At this time, there is not near enough memory to implement a scope function - maybe in the version 2 device?
-- Dr David Kirkby Ph.D C.Eng MIET Kirkby Microwave Ltd Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD, Essex, CM3 6DT, United Kingdom. Registered in England and Wales as company number 08914892 Tel 01621-680100 / +44 1621-680100
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Interesting.? Is there a schematic?
Mike WY6K
"... somewhere in the distance, there's a tower and a light, broadcastin' the resistance, through the rain and through the night..."
toggle quoted message
Show quoted text
On Tuesday, October 8, 2019, 7:52:03 AM CDT, erik@... <erik@...> wrote:
Would it be wonderful if there would be, next to the nanoVNA, a nanoSA or nano Spectrum Analyzer?
Well I decided to test what the most simple SA could look like, just good enough to test the harmonics level of your signals till 400MHz and some other, not too complex, measurements.
According to my estimate the BOM of the nanoSA on the photo would be around 12$
Main components are two SI4432 modules, one in RX mode at 443MHz using the RSSI as log detector, one as +20dBm LO for the mixer (443MHz - 886MHz), a 443mHz SAW filter as first IF filter, a Double balanced diode mixer and an arduino zero (3.3 volt) or compatible (arduino micro with 3.3v serial to USB module will also work), adding a LCD will still keep the cost below 25$ or 50$ retail.
The measurement performance is surprisingly useful.
Attached a scan of the harmonics and spurs of a SI5351 at 25MHz
And a scan of the AD9851 ast 25MHz, both connected through a 30dB attenuator
Specs:
Range 0-400MHz (0-200MHz with unmodified modules)
RBW selectable between 3kHz and 600kHz
With RWB=300kHz noise floor below -90dBm
Max signal around -5dBm
Did not yet do the IIP3 measurement but the used ADE-25MH is supposed to be +13dBm
Good enough for many measurements.
Things to further improve:
- 400MHz low pass filter at input
- remove output filter of TX module to get full 400MHz bandwidth
- Put everything in a box.
I hope someone gets inspired and puts everything on a PCB with a LCD as a small standalone SA (nanoSA)
|
Actually yes.? We have successfully used the RTL-SDR and the Airspy.
Mike WY6K
"... somewhere in the distance, there's a tower and a light, broadcastin' the resistance, through the rain and through the night..."
toggle quoted message
Show quoted text
On Tuesday, October 8, 2019, 8:06:58 AM CDT, Oristo <ormpoa@...> wrote:
If calibrated for amplitude at spot frequencies using nanoVNA,
then could some SDR (e.g. SDRplay has Android API) be useful for spectrum analyses?
|
To the potential developers:? I would like to point out that spectrum analyzers that go up to 1 GHz are quite affordable - used obsolete HP etc.? And there are new $170 ones already available, such as the RF Explorer.? This is a very nice and powerful handheld unit in a nice enclosure that goes up to 960 MHz.? RF Explorer has other models that go up to 2 GHz.? There are no inexpensive commercially available Spectrum Analyzers that cover 10 GHz, despite the fact that all that is needed to turn one of these other units into a 10 GHz SA is a mixer.? Even obsolete used HP SA units that cover 10 GHz still cost $5000+ and new ones are $40000+.
Is there a need for a $50 1 GHz SA?? Yes.
Is there a tremendous need for an inexpensive SA that goes up to 10 or 22 GHz? ABSOLUTELY!??
An affordable microwave SA, combined with NanoVNA V2 (up to 3.5 GHz), will open up microwave work to legions of people who have always avoided it because they didn't have the necessary instruments.? That would be a very good thing!
Mike WY6K
"... somewhere in the distance, there's a tower and a light, broadcastin' the resistance, through the rain and through the night..."
toggle quoted message
Show quoted text
On Tuesday, October 8, 2019, 11:16:11 AM CDT, Paul Beauvilliers <paul.beauvilliers@...> wrote: To the extent that this encourages present or future developers out there: A spectrum analyzer, with a tracking generator, that covers "below HF" through "above UHF", with user-selectable RBW and VBW, for around 50 USD would be ... awesome! [FWIW, I'm "blown away" by the nanoVNA ... so my thanks to those developers.] Paul WB1EMK On Tue, Oct 8, 2019, 10:02 Pierre Martel <petem001@...> wrote: If I can say a little something about this Idea.
A tracking generator would not cost a lot more in ressources and would
be a nice addon in a NanoSa.
And the possibility to add an amplifier to the TG to bring the level
to 30 DBm (1watt) would also be cool.
And lastly with the Generator in the TG, if you can modulate the
signal with a tone at a deviation level you can set, we could do some
really nice stuff.
With that said, I have a nice pelican box that could house all of
those nice device with a large rechargeable bank of Lithium/ion
battery lots of cable and adaptors. A Raspberry Pi4, 2 hdmi touche
screen And we have a portable RF labs..
Le mar. 8 oct. 2019 ¨¤ 09:18, Larry Rothman <nlroth@...> a ¨¦crit :
On Tue, Oct? 8, 2019 at 08:51 AM, <erik@...> wrote:
Would it be wonderful if there would be, next to the nanoVNA, a nanoSA
or nano
Spectrum Analyzer?
Well I decided to test what the most simple SA could look like, just
good
enough to test the harmonics level of your signals till 400MHz and
some other,
not too complex, measurements. Thanks for playing with this idea, Erik.
There was a comment from a Japanese NanoVNA user on Twitter comparing
the use of the Nano to an oscilloscope that is in the same price range but
has poor specs.
They gave an example of JYE Tech's 200KHz bandwidth scope kit for $30 vs the Nano's capabilities - image attached.
At this time, there is not near enough memory to implement a scope function - maybe in the version 2 device?
|
Small post giving some background on the building and tuning of the 2GHz cavity filter. I was able to use my nanoVNA to check the tuning of this filter as described in another post -- NanoVNA Wiki: /g/nanovna-users/wiki/homeNanoVNA Files: /g/nanovna-users/filesErik, PD0EK
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Oristo
WY6K Mike Watts