Tbolts been good for my uses. Nice and simple no muss or fuss. I think I paid $139. Regards Paul.
On Fri, Jun 28, 2013 at 11:45 AM, Bob Camp <li...@rtty.us> wrote: > Hi > > Ok, so the 100 MHz cleanup oscillator hopefully will be about -130 dbc / > Hz or better at 100 Hz offset. That would mean a -150 dbc / Hz OCXO is > roughly a tradeoff at 100 Hz. At 1KHz your cleanup oscillator should be > around -150 to -160. That would put the 10 MHz at -170 to -180 to be in the > same ballpark. You will have trouble getting a divider and phase detector > to hit -180, so the simple answer is to keep things cheap and roll off > inside about 100 Hz or so. Spurs are an unknown, but they likely will mean > you want to roll off sooner rather than later as well. > > I'd go shopping for something that's got better than -155 dbc / Hz at 100 > Hz and see what you can find. The TBolt OCXO meets that, there are other > OCXO's that also do so. The auction sites often have TBolt pulls for < $40. > I'd stick with a modern hermetic part if possible. It'll make for fewer > issues down the road. > > Bob > > On Jun 28, 2013, at 10:22 AM, Jim Sanford <wb4...@wb4gcs.org> wrote: > > > Bob: > > Thanks. > > You correctly anticipated that I will use this to lock a 100 MHz > Oscillator, and either multiply or lock from there. (I'm considering a > VCXO at 1GHz as well, it would either be locked to 100 MHz or 10 Mhz. > Haven't decided yet, also considering multiplying up to 1000 and then from > there to 2Ghz, 3Ghz, and 5. Haven't decided about 10 Ghz yet. > > > > Appreciate the info. The units on ebay are cheaper than the VCXO I was > considering (first time I looked, they were more), so will probably just do > that. > > > > Thanks again, > > Jim > > wb4...@amsat.org > > > > On 6/28/2013 10:07 AM, Bob Camp wrote: > >> Hi > >> > >> > >> On Jun 28, 2013, at 9:45 AM, Jim Sanford <wb4...@wb4gcs.org> wrote: > >> > >>> All: > >>> > >>> My Z3801 no longer works, and I've not been able to get any new ideas > on it, so am looking for a replacement. > >>> > >>> I've come across a nice 10 MHz that has very good phase noise (-145db > or so at 10 KHz offset), but costs $175 in single quantities (digi-key, I > think.) > >> The OCXO in the TBolt is about -165 at 10 KHz > >> > >>> I was considering using one of W1GHz's boards to lock it to a jupter > GPS engine that I already have. Several people have told me this is > overkill, recommending the Thunderbolt. > >>> > >>> I've read that there are various OXCXs used in Thunderbolts, some OK, > some not so good. > >>> > >>> Looking on ebay right now, I see a Nortel Trimble NTBW50AA, a > Symmetricom, NTBW50AA, and another Nortel. > >>> > >>> Does anybody have experience with these? > >> Yes > >> > >>> I'm particularly interested in the best phase noise I can get. > >> Spurs are what will kill you. > >> > >> Phase noise is about 10 db worse than the TBolt far removed. It's > similar close in. > >> > >>> This will be station master frequency reference, and will ultimately > lock stations up to 10 GHz. > >> Simple answer is to run a clean up oscillator at 100 MHz and then go > from there. None of the GPSDO's have low enough spurs to really do an > excellent jobs at 10 GHz. > >> > >> > >> Bob > >>> Thanks & 73, > >>> Jim > >>> wb4...@amsat.org > >>> > >>> _______________________________________________ > >>> time-nuts mailing list -- time-nuts@febo.com > >>> To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >>> and follow the instructions there. > >> _______________________________________________ > >> time-nuts mailing list -- time-nuts@febo.com > >> To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >> and follow the instructions there. > >> > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.