On Mon, Jan 18, 2021 at 11:46 PM, Erik Kaashoek wrote:
It seems your attenuator is bad.
You can verify this by enabling the cal output at 30MHz (MODE/Cal Output/30MHz) and putting the tinySA in low input mode with center 30MHz and span 10MHz.?
Set LEVEL/ATTENUATE/MANUAL 0 (0 dB attenuation) and write down the level of the 30MHz signal
Then increase the attenuation in 1dB steps and see how the noise floor moves up and the level of the 30MHz signal stays the same.
If the 30MHz signal level suddenly makes a jump up or down when changing the attenuation write down the attenuation levels before and after the jump and post your observation.
Erik,
? To take the drudgery out of manually entering 31 attenuator values, would it be possible to either add a module to TinySA-App (Settings?) that performs an extended attenuator test, as outlined by yourself above, or write a separate executable that performs an extended attenuator test?? An extended attenuator test would also help hugen to detect a device with a borderline bad attenuator in the QA process before shipping it.
? Does the manufacturer? specify the number of operations the attenuator can be switched (MTBF?) before it needs to be replaced?
? I can throw something together for myself in C#, but my programming skills are not good enough that I would trust publicly releasing an executable.
- Herb
