Hi For the limited temperature swings that most labs have, and the sort of ADEV that the OCXO has, a Q up to 10 can be tolerated pretty well. Keeping the parts count down to two to four coils and a few capacitors lets you do it without a lot of complex design tools. They did it with charts and slide rules back in the 1940’s. You can do it with a few clicks on a web based calculator app these days.
Bob > On Nov 18, 2014, at 8:10 PM, Magnus Danielson <[email protected]> > wrote: > > Hi, > > The low Q values has the benefit of being very phase stable. > > Low Q dips can be put in to null out particular overtones, LCR-series loading > the signal to ground at suitable place. Also very traditional 1930-1950 era. > > Cheers, > Magnus > > On 11/19/2014 01:30 AM, Bob Camp wrote: >> Hi >> >> Single stage NPN 2N5179 or 2N918 or 2N2222 or … biased to generate a >> collector current that looks like a “raised cosine” (see your 1952 RF >> transmitter textbook). Tune the collector to the desired output. Set the Q >> to something like 10 or so. Linear “class A” stage after that. Tune the >> collector with another Q 3 to 10 tank. Match it to the load with a PI or a >> Tee. >> >> Bob >> >>> On Nov 18, 2014, at 6:21 PM, Doug Ronald <[email protected]> wrote: >>> >>> I doubled my Austron 1250A from 5 MHz to 10 MHz with 2 NPNs fed in >>> push-pull and output in parallel with a tuned circuit. Before buffering it >>> with an LH0063, I fed the signal through a 10 MHz crystal, purchased at a >>> local surplus electronics store for $0.95. The 2nd harmonic is about 70 dB >>> down. >>> >>> -Doug, AE6SY >>> >>> -----Original Message----- >>> From: time-nuts [mailto:[email protected]] On Behalf Of Bob Camp >>> Sent: Tuesday, November 18, 2014 3:11 PM >>> To: Discussion of precise time and frequency measurement >>> Subject: Re: [time-nuts] ks... answers The emails are getting long >>> >>> HI >>> >>> Actually there are three different approaches to the “double 5 MHz” >>> question. >>> >>> Roughly 99.99% of all doubler / tripler OCXO’s out there do the trick with >>> a simple single transistor stage and a tuned tank. Follow it up with a >>> tuned single transistor output amp. Cheap, easy, not very fancy, gets >>> people mad when mentioned. It works plenty good enough. The basic design >>> approach dates back to tube based multipliers done in the 1920’s. Just >>> about any transmitter design textbook from 1930 through 1960 has design >>> charts and tube based examples. >>> >>> Bob >>> >>>> On Nov 18, 2014, at 4:26 PM, paul swed <[email protected]> wrote: >>>> >>>> Don >>>> The two units work together by a buggy cable from what I have heard so far. >>>> The Ref0 is the master that drives stuff it connects to REF1 that >>>> disciplines REF0. >>>> If GPS goes away or the ref1 it all keeps ticking. This is been teh >>>> system design for about 20 years. >>>> >>>> Many of us have the ref1 only and the internal osc is 5 Mhz so thats >>>> why you have seen discussions on multipliers here. Tap the 5 Mhz >>>> double it filter it and buffer it. there seem to be 2 schools of >>>> thoughts on the process. Balanced mixer or Wenzel. >>>> I would have hacked the answer already. But I need to keep my ref1 >>>> running so that it ages in. ASI will refund your money if bad. But only in >>>> 30 days. >>>> I do like what I see from the KS-... Can never remember the number. >>>> Regards >>>> Paul >>>> WB8TSL >>>> _______________________________________________ >>>> 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. >>> >>> _______________________________________________ >>> 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. >>> >>> _______________________________________________ >>> 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. >> >> _______________________________________________ >> 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. >> > _______________________________________________ > 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. _______________________________________________ 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.
