From: Dr Bruce Griffiths <[EMAIL PROTECTED]> Subject: Re: [time-nuts] ? phase comparison or other device Date: Mon, 25 Jun 2007 20:37:29 +1200 Message-ID: <[EMAIL PROTECTED]>
> Ulrich Bangert wrote: > > Pete, > > > > > >>>> 5. Mini-circuits BLP-1.9 low pass filter. > >>>> > > > > terminating the mixer if output with an lowpass/bandpass filter and NOT > > with an diplexer is not so good an idea. Where does the rf go? > > > > Best regards > > Ulrich Bangert > > > > > Ulrich > > This depends on whether the low pass filter has a shunt capacitor at its > input or a series inductor. > With the shunt capacitor the RF is shunted to ground through this capacitor. > With a series inductor the RF sees a relatively high input impedance and > the mixer will not perform well. Depends on what you want to acheive. NIST made some experiments and found that this was indeed what increased the gain in the frequency comparisions they made. They where infact a bit supprised as this was contruary to what they beleived. It's in the NIST archive, but I could pull the document number out if given some chance to dig around. So, what is normally a good thing in RF may not necessarilly be the best strategy for frequency comparision, at least when it comes to mixers. Cheers, Magnus _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
