I was actually thinking about this quite a bit and perhaps I went the wrong way. That is a cheap vcxo class device. His unit was not an oven as I recall. Just maybe a bit too good was actually bad. Hard to say and no time to play right now. Regards Paul WB8TSL
On Wed, Jul 22, 2020 at 6:06 PM Bob kb8tq <[email protected]> wrote: > Hi > > > > > On Jul 22, 2020, at 3:51 PM, paul swed <[email protected]> wrote: > > > > Ray watch out for my comment on the KD2BD solution. That oscillator isn't > > available and I have not been able to map something else into it. Tried > > several good grade Oven oscillators. Just be aware of that issue. > > Would need to do more tinkering and simply don't have that time right > now. > > Also it would be great if the oscillator was something that could be > > obtained at a reasonable cost. I do not believe at all it has to be a > > OCXO as the older true time and spectracoms were not and they locked > solid. > > So its a case of getting the control voltages right. > > You can buy a surprisingly good little OCXO (for the price) on eBay these > days in the $3 to $6 range. Find one at 12.6 MHz and it will divide > nicely to > 60 KHz. 19.2 MHz looks like a better candidate … Either way I have not > (yet) > seen a 60 KHz multiple show up in the cheap category. > > Bob > > > > Regards > > Paul. > > > > On Wed, Jul 22, 2020 at 3:29 PM <[email protected]> wrote: > > > >> Thanks to all for the suggestions. I dug a ferrite rod AM radio antenna > >> out of the box this morning. I have a box of 10 left over from the late > >> 80s. It measures 0.950 mH so I will add some turns to get it to 1.5 mH > >> which will be easier to resonate at 60 kHz. Then I need to build up the > >> RF amp and run the output through a 60 kHz crystal filter. I have to > >> order the crystals since I don't have any on hand. It will take a couple > >> of weeks to get the front end working. > >> > >> I am in Phoenix so the WWVB signal is of decent quality here even during > >> the daytime. My 25 year old cheap Casio watch will sync up within 2-3 > >> minutes any time of day or night. It normally syncs at 2 am but I have > >> done tests to confirm daytime sync works reliably. > >> > >> Mark, I know virtually nothing about SDR other than it works. I bought a > >> RTL-SDR.Com module a couple of years ago and played with it a little > >> bit. But it quit working and I haven't thought about SDR since then. My > >> Icom 7300 is a SDR and it works very well. I think to attempt to design > >> a SDR would be well over my head. I anticipate this project taking 2-3 > >> months. If I get it working I will be glad to share everything with the > >> group. > >> > >> Lester and Paul, I will test with the Costas loop as it may be the > >> easiest way to go. To test the Costas loop I am basically going to > >> duplicate the KD2BD design. I was reluctant about it in the beginning > >> but more reading seems to indicate it will be fine. My AWG allows me to > >> set the phase from 0 to 360 degrees independently on each channel so I > >> can use that for initial testing. That testing can be done prior to > >> getting the front end working. > >> > >> Richard, is your software posted somewhere? I assume it allows you to > >> specify the time and date you want it to send. That would come in handy > >> for writing the code to extract the timer/date data. I have seen > >> examples of the Arduino transmitting the old AM signal but don't recall > >> seeing one that sends the BPSK stream. > >> > >> I have a GPS time receiver with a 1.2 inch LED display that I built a > >> couple of years ago. I have it setup so the UART outputs the gprmc NEMA > >> string in case I want to look at it. I have a couple of spare GPS > >> modules lying around and several Arduino Uno modules. I have no problem > >> picking up the GPS satellites using only the patch antenna that is built > >> into the modules. > >> > >> Ray, > >> AB7HE > >> > >> > >> _______________________________________________ > >> time-nuts mailing list -- [email protected] > >> To unsubscribe, go to > >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > >> and follow the instructions there. > >> > > _______________________________________________ > > time-nuts mailing list -- [email protected] > > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
