On Fri, Aug 14, 2020 at 01:52 PM, gary wrote:
1. What does the menu item 'correct frequency' under the 'expert config' menu do?
? ??
? ?[I haven't used that setting yet, so I'll leave it to Erik to answer.? I'm guessing it isn't for correcting a marker frequency at full span.]
2. The frequency displayed by the marker is 159.861 MHz for an actual input frequency of 160 MHz.
? [The frequency resolution of the display is dependent on the frequency span and and the display points.? From your marker reading it appears you are measuring the 160MHz input using a 0 - 350MHz span. The tinySA has 290 display points, so for a frequency span of 350MHz each display point is:?350e6/290 = approx. 1.2MHz apart.? The closest points to 160MHz using that increment are 159.861MHz and 161.072MHz.? If you need finer frequency resolution you need to use the 290 display points over a narrower span (i.e center frequency = 160MHz and span = 10MHz).]
3. Under the same 'expert config' there is an 'actual power' item. What does it do?
[Expert Config->Actual Power works like Config->Level Cal but allows you to use an external signal generator instead of the built in calibration output as your reference source.? If you want to perform a level cal on the HIGH INPUT then actual power using an external generator is the only way to do so.]
4. The level calibration seems to be a fixed table with interpolation. Is it possible to modify that?
[See the wiki topic???regarding modifying the correction table]??
5. The level is consistently off by 0.5 to 1dB.
?[From the CALIBRATE wiki, "?Directly after calibration the power level display error is expected to be below +/- 2dB".? If you are measuring 0.5 to 1dB off then your measurements are well within the expected display error.
As a comparison the display error for my Wavetek 8541 power meter is +/- 1dB, and I could purchase 15 tinySA's for what I paid for it and the accessory power sensors.? If I need to measure with better than 1 dB accuracy I substitute? a signal from my rf generator at the same level as the signal displayed on the tinySA and record my generator output as the measured level. ]
- Herb
