tinySA calibrating the high input

A short video describing how to do the level calibration of the high input using the calibrated low input
For more information go to tinysa.org

[@dschmider]

Hi, I just had mine arrive, and I have to say I'm really happy with it. Would I be correct in saying that if I bought second TinySA, I could use the Siggen function with the method above? So far, as I am measuring gfsk transmitters at 869.75MHz with a 40dB attenuator its reading pretty good, but I'd like to be a little more certain. Cheers!

[@ErikKaashoek]

Yes, you can use the low output from one tinySA to calibrate the high input from another tinySA. Keep in mind the high input is factory calibrated and probably correct within 3dB

[@W4BTK]

Erik thanks for the video. One thing I did also was, using a service monitor such as the HP 8920A, to generate a signal at -30dBm, I calibrated both low and high inputs. Is this a valid process after performing the Initial calibration process highlighted on the tinysa website?

[@ErikKaashoek]

Yes, very good!

[@zeljkoadzic1692]

new firmware not have actual power

[@aciscarcab]

What do you think about using the 300MHz armonic (from the 30MHz Cal. output build in) to calibrate? When you activate the 30MHz Cal. output, and you put the SMA bridge, the same signal is present in both High and LOW inputs.

[@ErikKaashoek]

That was what I was hoping for but due to internal reflections and differences in drive power of the 30MHz clock output the 300MHz harmonic has an unpredictable difference in power level at the high input versus the low input so the factory calibration has more accuracy and I decided not to use the 10th harmonic. (the same is true for the other harmonics reaching the high/low overlap range)

[@aciscarcab]

@@ErikKaashoek Thank you. Yes, the factory calibration is quite accurate.. The deviation from factory calibration was only 1 dB. After a right calibration with an external source , I see that (in my TinySA) the measured difference of these harmonics in the overlap range (240, 270 ,300, 330 MHz) is between 5.5 and 6 dB higher in the high input. If that were the same for all the TinySA´s... can create a rule to calibrate.

[@ErikKaashoek]

@@aciscarcab it's not the same for all

[@ErikKaashoek]

@@aciscarcab Its not the same in all tinySA

[@chrisgroenewegen3756]

Hi Erik, I'm owning a SDG2042X from Siglent. Which signal generator is able to provide a known signal of e.g. 250Mhz? Those would be I assume quite expensive? Looking for ways to calibrate the high input too.

[@ErikKaashoek]

In general the high input is without calibration accurate within 2dB so no real need to calibrate. You can however calibrate using any stable signal between 240MHz and 350MHz. Even a DBV-C or ATSC cable TV signal will work. Using your SDG2042X you can program a signal with a LOT of harmonics and use one of the harmonics to do the calibration.

[@chrisgroenewegen3756]

@@ErikKaashoek Ah Erik, I now remember you made a comment on taking a std TV signal from ATSC indeed. Thanks for the tip regarding the SDG2042X appreciate it. Still many things to learn and no time. ;-)

[@BenHydeSPARKScience]

I'm totally lost... At the 1:00 mark, you say that the "signal generator is hooked up..." How do you do this?

[@ErikKaashoek]

Any signal from any device supplying a stable signal between 240MHz and 350MHz can be used. Can even be a Cable TV signal.

[@Ibelieve218]

I have no signal in the required band for teh high.I checked on signal generators there not cheap and i really dont want to drive around looking for a signal seems like thats the only draw back

[@ErikKaashoek]

Yes, but the high input is (as explained in the wiki) for free so it has its limitations. The measurement error is anyway less then 2dB when uncalibrated

[@stevencraig]

Hi Erik, I no longer see the "Actual Power" setting on the expert config menu. Has it been removed or renamed? My firm we are is v1.3-265

[@ErikKaashoek]

The actual power is moved to a submenu

[@stevencraig]

@@ErikKaashoek I never thought to look in a submenu. I've found it now, thanks. Is the manual on your website editable like a wiki, (i.e. open source)? It still reflects the old menu structure and I can look into updating it.

[@ErikKaashoek]

@@stevencraig Yes, the wiki is user editable. Contact me via email and I will provide you with the details

[@Ibelieve218]

Newer one does not have power I have level in or output??? So how do you calibrate this one??

[@ErikKaashoek]

I do not understand your question

[@Ibelieve218]

@@ErikKaashoek mine I just bought recently. If you go into config, more I have Level correction don't see power level setting. There are no power level corrections

[@Ibelieve218]

in level correction there's setting for input level and output level

[@ErikKaashoek]

Please join this group for support groups.io/g/tinysa/messages

[@Ibelieve218]

I don't have a signal generator you said I can use low to get the high done

[@ErikKaashoek]

You can use any stable signal that is within the frequency range of both the low and high input. It could even be a cable TV signal. You can NOT use the harmonics of the calibration output.

[@Ibelieve218]

@@ErikKaashoek thank you I found one set it for center then went to high and followed your direction thank you