[time-nuts] LTE-Lite Plans
djl at montana.com
Wed Nov 26 13:55:14 EST 2014
> On Nov 26, 2014, at 11:45 AM, Jim Sanford <wb4gcs at wb4gcs.org> wrote:
> Please DO share. Thanks!
> On 11/25/2014 7:47 PM, Didier Juges wrote:
>> I have somewhere a piece of VB 6.0 code that decodes NMEA sentences and puts it pretty on the screen (at least that's how I remember it :). I am not at home at the moment but I'll be glad to send it to you if you are interested. May not do what you want, but it will get you started.
>> Didier KO4BB
>> On November 25, 2014 1:42:42 PM CST, Jim Miller <jim at jtmiller.com> wrote:
>>> I have one of the LTE-Lite 20Mhz units and plan to use it as a
>>> reference for my ham radio gear. My planned setup is as follows:
>>> I'm putting it in the recommended Hammond enclosure powered by a USB
>> >from my PC. I had originally planned to use the wall wart provided but
>>> want to get status from the unit without hacking a window in the top to
>>> the LEDs so I plan to use TBD software to provide a status check. I
>>> thought about doing something with an Arduino and display shields but
>>> seemed like too much work for now.
>>> I'm using a inverting D FF from TI (SN74aup1g80) as a divide by 2 to
>>> provide 10Mhz. The chip and associated passives will be on a little
>>> board mounted in the open area normally reserved for the external
>>> oscillator. The output of the chip will be connected via a series
>>> of about 400 ohms to a SMA connector. This resistor will limit the load
>>> the FF and the LTE-Lite power source. Power will be taken from C6.
>>> This output will only go a few inches to a DEMI 10Mhz 4 way splitter
>>> input of the splitter will be equipped with an additional ERA-2+
>>> (50 ohm input) which will restore the signal levels lost due to the
>>> resistor in the LTE-Lite addon. The DEMI splitter will also be equipped
>>> with a manual power switch which will allow me to kill the output of
>>> box if the GPSDO fails for some reason.
>>> The little hockey puck antenna will be mounted directly outside the
>>> wall near a south facing wall which will limit the visibility to only
>>> the horizon. I'm assuming this will be enough for my modest needs.
>>> The four outputs will be used as follows:
>>> One will go to the K3 ExtREF to provide an external reference.
>>> Two will go to separate TX/RX converters for low frequency (<600Khz)
>>> and be used with the transverter I/O on the K3.
>>> The last will be used as a general calibration reference.
>>> When the power switch on the DEMI splitter is turned off the K3 will
>>> to using its internal TXCO.
>>> I leave the PC running 24/7 and the power to the LTE-Lite would only be
>>> interrupted when the PC is rebooted. I don't need a frequency reference
>>> during the reboot time since I always operate my rig with the PC on and
>>> running. The TBD status software will tell me when the LTE-Lite is
>>> up again. The PC is served by a UPS and the shack circuit is one which
>>> served by our whole house generator.
>>> I have the DEMI splitter built up and working. Now just waiting on
>>> enclosure from Digikey. I should have everything running by mid
>>> I still need to figure out what to use for the status software. Ideally
>>> like an applet to display appropriate status indications on my monitor
>>> now I'll examine the uBlox and Putty and if not satisfactory perhaps
>>> write something in VB.
>>> Feedback and suggestions welcome.
>>> Jim ab3cv
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