After posting my message about using an external frequency reference for a K3 and a QS1R, I got some really nice input and feedback from W7AVK, K3KO, N4ZR and NK4I. A big thanks to these gents for sending me input and experience with different solutions.
All the input has been very useful this weekend as I have searched around for a single time reference solution for my needs. (everyone is going to be different) I thought this might help others that want to go down this path if they have similar wants / needs. I decided to still go with a Trimble Thunderbolt Rev. E ~2004 manufacture. This isn't going to be the lowest cost solution, but it covers my needs for the following: 1. Provide a very stable 10mhz external reference for my K3... mainly for fun and I might send in some reports to the ARRL FMT etc.. so there goes $$$ for the external freq reference add on for the K3. 2. The main reason I started going down this path was to use the external frequency reference input on the QS1R I run for the NC7J CW Skimmer. NK4I saved me a bunch of time (no pun intended) and pointed out the fact that the direct output on the Trimble TBolt won't work with the QS1R. Pete pointed me to Graham VK3XDK and David VK3HZ's XRef which will provide a 125 MHz reference for the QS1R from the TBolt 10 MHz output http://www.vk3hz.net/XRef/XRef_Home.html#XRef-Vx I exchanged email with David and have a XRef-Vx on the way... some more $$$ for the XRef-Vx shipped. Seriously not bad at all considering it has a TCXO on board that will take over if the Trimble output lock is lost. 3. Use a PPS reference to drive an NTP Stratum 1 server from my house. I get this out of the TBolt and also from most of the other solutions provided, but the TBolt has some other really nice monitoring capabilities. So for the NTP server, I ordered the latest Raspberry PI $50 with a case shipped and I searched high and low for other implementations using a TBolt with Linux / Raspberry PI for a GPS disciplined NTP PSS reference. Google 'time nuts' which I'm sure many on this list are familiar with... and I quickly found KO4BB's Thunderbolt Monitor Kit: http://www.ko4bb.com/Timing/GPSMonitor/kit.php Which will be a nice display for the serial output on the TBolt as it drives the NTP server (and QS1R and K3 when I'm operating) ARound $80 for this kit when Didier gets the next batch ready. This monitor kit also includes a PPS stretcher to increase the 10uS PPS pulse output by the TBolt to ~1mS. So that is my reasoning to stick with a TBolt... they seem to be holding their value if not getting more expensive and there is all the nice work and comparisons that have been done by KE5FX http://www.ke5fx.com/gpscomp.htm along with his Lady Heather software. It's pretty clear that the TBolt can still hold it's own. At the end of the day, do I need all this precision? Not really, but it's obsessive and fun! I get to spend more $$$ and have stuff shipped to me from around the globe and play with ntpd and cool software... provide a better service to the CW Skimmer community and precision time community with the NTP server. Plus I'll give the ARRL FMT a try and have some more fun. Thanks again for all the input off the list by the guys above. Max NG7M On Wed, Apr 1, 2015 at 8:27 AM, M. George <[email protected]> wrote: > I'm looking for a Trimble ThunderBolt Rev E primarily for an external > reference to be used on the NC7J CW Skimmer Server (which I sysop).... for > our QS1R SDR. telnet:dxc.nc7j.com > > Poking around and doing some research, it's clear I missed the opportunity > a number of years ago to get one for less than $100. > > If anyone has one sitting around or an extra they would like to sell, let > me know... on eBay I see them going anywhere from around $125 to $250 at > times, but the auctions are not showing up on a regular basis. > > Hit me up off the list here if you have one you would want to sell. I'll > put it to good use keeping the skimmer server spots at NC7J spot on. ;) > > Max NG7M > > -- > M. George > -- M. George ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
