Helloo Marcus and thank you! I have already did some tests with the two physical channels, fom TX to right before the X300 SMA ports, once with: Ch1->RX1, Ch2->RX2; and then I exchanged to: Ch2->RX1, Ch1->RX2. The results showed instability with temperature gradients in RX1 only. This throughs suspitions mainly to what comes after, hence the USRP device. The main suspect for us is obviously the TwinRX. More specifically the temperature gradients inside the x300 case, being that RX1 SMA port is nearer to the case's edge. Could it be the reason? If that is so, do you recomend to take the device off from it and use it like that?
Regards, Arjan On Mon, Jul 12, 2021, 7:10 PM Marcus D. Leech <[email protected]> wrote: > On 07/12/2021 11:44 AM, [email protected] wrote: > > > > Hi all, > > > > I am measuring the power of two signals (sinusoids) through an RMS > > calculation, using an TwinRX on a x300 motherboard. In the calibration > > process (lab conditions, no noise, no interference) I’m trying to > > obtain a differential power (p1-p2) of 0dB or at least constant at > > ±0.5dB . One of the channels, RX2, is highly stable with respect to > > the environment temperature variations, while the other one, RX1, is > > much less so. > > > > I am aware that this might be a very particular use case, but was > > wandering if anyone had had this kind of experience or at least knows > > if there is any documentation/datasheet concerning temperature > > sensibility of these two components? > > > > Best regards, > > > > Arjan > > > > > RF components have a temperature dependence. Amplifiers typically these > days have a gain-vs-temperature coefficient of roughly 0.05dB/C. Cabling > also has a temperature-vs-loss coefficient which varies with cable > length, cable type, and operating frequency. > > Something else that sneaks in is loose connectors--SMAs in particular > are notorious for developing temperature-related "funnies" while not being > obviously damaged. They need to be torqued properly. > > _______________________________________________ > USRP-users mailing list -- [email protected] > To unsubscribe send an email to [email protected] >
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