Pete wrote: > Arnold, > > I have had good experience with the SYPD series > from Mini-circuits. I have not seen any used, but > their new cost is reasonable. They do several things > well e.g. the DC offset on the units I received is > <1mV & they produce >2V p-p when driven @ > +7dBm. > > Pete Rawson > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > Pete
These are OK except when one needs to isolate the IF ground from the RF grounds to avoid low frequency ground loop problems. The RPD and MPD through hole series are better in this regard as they allow the IF ground to be isolated from the RF grounds. The flicker phase noise characteristics of the mixer/phase detector should be measured as some mixers/phase detectors have lower flicker phase noise than others. The termination of the IF port will affect the mixer phase noise. For offset frequencies < 100kHz a capacitive termination of the IF port which reflects the sum frequency back into the mixer reduces the mixer phase noise. The tradeoff is that the mixer output at higher offset frequencies is attenuated by the IF port termination. Terminating the IF port in a capacitor reduces the RF port impedance, so that a low value series resistor (22 to 39 ohms - select for lowest VSWR) is then required to improve the RF port VSWR. Terminating the IF port with a capacitor also alters the mixer gain (as a phase detector) so this needs to be measured in conjunction with the noise 10514 and 10534 mixers using discrete diodes supposedly have lower flicker noise than mixers using integrated quad diodes. Bruce _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
