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S meter readings 32 or 64 bit versions
Posted: Tue Oct 13, 2020 9:19 am
by GW4NNO
I am using Thetis v2.8.8 with Windows 10 and Anan 7000DLE mark II. I have both the 32 and 64 bit versions of Thetis installed. Strangely, I seem to be getting S meter readings about 4db higher in the 64 bit version than I do in the 32 bit version. Signals actually sound louder too and appear stronger on the spectrum display. Is there some signal strength calibration difference between the two versions? and how do I know which version is giving the correct signal level of 50 micro volts for S 9 at -73dbm. I used my Metrovna antenna analyser is an rf signal generator to proide a stable signal so I know the difference is not due to on air signal variations. Any comments welcome.
Re: S meter readings 32 or 64 bit versions
Posted: Tue Oct 13, 2020 9:43 am
by GW4NNO
Just noticed that there is a level calibration facility on the Calibrate screen so I presume the levels between my two versions are not calibrated at the same level. I have never altered this setting in either version so maybe the defaults are not equal. I presume therefore that I'd need an RF signal generator with calibrated output level to be abloe to adjust this setting correctly.
Re: S meter readings 32 or 64 bit versions
Posted: Tue Oct 13, 2020 11:27 am
by w-u-2-o
That's an interesting report. I will compare both versions here when I get a chance later today.
Re: S meter readings 32 or 64 bit versions
Posted: Tue Oct 13, 2020 11:30 am
by Tony EI7BMB
not seeing any difference here so far
Re: S meter readings 32 or 64 bit versions
Posted: Tue Oct 13, 2020 11:39 am
by GW4NNO
Okay thanks for that, it must just be something in my setup then. Maybe the level calibration has been changed in one or other of my database files.
Re: S meter readings 32 or 64 bit versions
Posted: Tue Oct 13, 2020 2:53 pm
by w-u-2-o
Without getting out my signal generator I can't detect any differences.
Re: S meter readings 32 or 64 bit versions
Posted: Mon Oct 19, 2020 10:28 pm
by AG5CK
I checked my 7000 dle mk2 against my signal generator over the weekend. I am using the 64 bit version of 2.8.7. I don't know that the sig gen is calibrated but it matched the S meter on the anan from -10 dbm until I got down to -120 dbm. At -120 and -130 it was only 1 point off. Since the anan and HP 8640B agree I will assume it's accurate.
Then I checked my Yaesu ftdx1200. At -73 dbm on the sig gen it was reading around S7. Turning on the preamp brought the reading close to S9. I it's hard for me get used to an accurate S meter when I've been fooled for years.
Re: S meter readings 32 or 64 bit versions
Posted: Tue Oct 20, 2020 12:17 am
by w-u-2-o
AG5CK wrote:Then I checked my Yaesu ftdx1200. At -73 dbm on the sig gen it was reading around S7. Turning on the preamp brought the reading close to S9. I it's hard for me get used to an accurate S meter when I've been fooled for years.
Oh, so true! Ha ha!
See the discussion on S-meter accuracy in this topic:
https://apache-labs.com/community/viewt ... f=6&t=2463