I measured noise level of the phase tracker by inputting constant frequency RF signal from marconi.
Measured frequency noise was ~2 Hz/rtHz @ 100 Hz. It's not so good.
What I did:
1. Unplugged 11MHz marconi and put RF signal to the beatbox from this. Frequency and amplitude I put are 100 MHz and -3 dBm.
2. Measured spectra of phase tracker outputs, C1:ALS-BEATX_FINE_PHASE_OUT, C1:ALS-BEATY_FINE_PHASE_OUT.
3. Calibrated using the factor I measured (elog #8199).
4. Put marconi back to orignal settings.
- According to Schilt et al., this noise level is not so good.
- By changing the delay-line cable length or optimizing whitening filter etc., we can improve this.