S Meter issue ( FIXED!)

[DL2XY]

Or you may try to patch the database directly.
Setting the values to zero would reset the calibration.

Database RX Calibration.png (69.18 KiB) Viewed 2677 times

[w-u-2-o]

IIRC, there are many, many more places in the database than those that are touched by the calibration routine.

[Chiron]

Can it been solved by using (going back to) 2.9.0.5 and do the calibration and save it. Then go to version 2.9.0.6 again?

yah probably, but have not tried myself

Hello Richie,
I can confirm that using your latest master branch 2.9.0.6 and compile it, the generated 2.9.0.7 does store the calibrated value.
I can also see some Smeter additions. After succesfull storing the s-meter calibration, I can start version 2.9.0.6 again with the correct S-meter values.

My S-meter calibration problem is solved now.

[WM4CH]

I thought I would update this.

I had some family health issues that took priority for a few months and I finally sent the radio to Doug last week and got it back yesterday.

The previous owner had overloaded the radio and the low pass filter on the RX1 path had blown so the Rx1 signal was down about 30db.

Doug replaced the filter and the protection diode which was not blown. So it appears the previous owner overloaded the Rx1 blew out the protection diode and the low pass filter, replaced the protection diode which didn't fix it and then sold me the radio. This is conjecture, but the only plausible situation where the low pass filter would be blown but the protection diode was not. The diode had obviously been replaced before by the looks of it. The bottom line the radio was sold to me damaged.

Doug fixed and I am now on the air with it. Doug does great work with a very fast turn around time.

[w-u-2-o]

Great news!

It's always shocking how many dishonest hams there are. You would think our hobby would attract a better class of citizen, but that's been proven far from true many times.

Doug is the man!

[WM4CH]

Yeah, Doug is great to work with

[n2gq]

. By default Thetis reports about 7dBm in excess, (a calibrated -73 turns into -66 dBm.)

Do not calibrate at -73dB !
This is an ADC-System, ADC's need to be calibrated near fullscale. -20dBm should be fine.

Calibrating at S9 means 1/1000 of fullscale voltage, so the software must extrapolate by a factor of 1000 meaning all measurement errors are multiplied by this factor too.

Hi
Would -43 ok for a lev calibration?

Jay n2gq

[DL2XY]

Hi
Would -43 ok for a lev calibration?

Jay n2gq

-43dBm (S9+30) should be sufficient.
-20dBm(S9+53) would be still better since at least15bits of the 16bit ADC are used.

Walter dl2xy

[n2gq]

Hi
Would -43 ok for a lev calibration?

Jay n2gq

-43dBm (S9+30) should be sufficient.
-20dBm(S9+53) would be still better since at least15bits of the 16bit ADC are used.

Walter dl2xy

Hi Walter
Okay I was going to purchase a s9 signal generator which has 3 different outputs. -43 being the highest, -73 s9 in the middle and -104 for s4 signal. They are for sale on ebay. Was also waiting on a TinySa ultra but they are still out of stock.

Thank you
Jay n2gq

[n2gq]

When calibrating the s-meter is a 1k tone used or just unmodulated carrier?

[w-u-2-o]

Just a carrier.

A tone would never be necessary for any sort of RF power measurement

In SSB there would be no difference between a 1KHz tone and a carrier except for the difference between the center frequency of the tone and dial frequency.

Just make sure the carrier is reasonably centered in the passband.

[n2gq]

Okay Scott
Thank you....

[KA9UVY]

Hey Jay, Be sure and let us know if the S9 signal generator works out for you... I tried an old signal generator I had here and it failed to work. I see the S9 sig generator has some different freq available but none of which are on even Mhz.
Thetis didn't let me put in anything other than the Mhz digit.?
Maybe I am missing the adjustment but no matter what I type in it jumps to the next even Mhz.

73, Robert
KA9UVY

[n2gq]

Hey Jay, Be sure and let us know if the S9 signal generator works out for you... I tried an old signal generator I had here and it failed to work. I see the S9 sig generator has some different freq available but none of which are on even Mhz.
Thetis didn't let me put in anything other than the Mhz digit.?
Maybe I am missing the adjustment but no matter what I type in it jumps to the next even Mhz.

73, Robert
KA9UVY

Hi Robert,
I changed direction and purchased a TinySA Ultra which can output -19dbm and you can set it to whatever frequency we use. I set the TinySa to -20dbm and then changed the value in Thetis to -20dbm as well as frequency and then press start.

[n2gq]

Hey Jay, Be sure and let us know if the S9 signal generator works out for you... I tried an old signal generator I had here and it failed to work. I see the S9 sig generator has some different freq available but none of which are on even Mhz.
Thetis didn't let me put in anything other than the Mhz digit.?
Maybe I am missing the adjustment but no matter what I type in it jumps to the next even Mhz.

73, Robert
KA9UVY

If you decide to purchase, go to RandL electronics. They have the legitimate device.

[KA9UVY]

Thanks Jay, I purchased a tiny SA and calibrated mine this evening.

The tiny SA will be handy to have here anyways, thanks for the tip on it.
73, Robert
KA9UVY

[rdwing]

The TinySA Ultra is packed with lots of great features, including the SA, signal generator, zero span, waterfall/fft, tons of useful built in measurement tools like OIP3, phase noise, harmonics, thd, channel power, and more. I use it with appropriate taps and attenuators for taking calibrated power measurements too. Can't more highly reccomend getting one. R and L is the place.

[n2gq]

Thanks Jay, I purchased a tiny SA and calibrated mine this evening.

The tiny SA will be handy to have here anyways, thanks for the tip on it.
73, Robert
KA9UVY

Cool, glad it worked for you as well.