http://rembl.org Seductive serendipity / Verleidende serendipiteit Sun, 22 Jun 2008 15:15:13 +0000 http://backend.userland.com/rss092 en UPDATE: As I already felt, the idea below is already implemented by Poul-Henning Kamp in his own implementation of a NTP-server, NTPns. I am trying to figure it out and will report the results here as soon as I got it running. ----------- This post tries to describe an experiment using DCF77 ... http://rembl.org/index.php/2008/06/09/dcf77-pps-experiments-with-a-dcf77-radio-module-using-ntpd/ Recently I bought a Motorola Oncore UT+ GPS timing receiver on Ebay. I run Debian Linux and it seems that the refclock_oncore driver is not included in ntpd because the LinuxPPSAPI from Rodolfo Giometti is not an official part of the linux kernel (yet? ; -) I interfaced the module with ... http://rembl.org/index.php/2008/04/19/motorola-oncore-ut-and-linuxpps/ Also this year Joe Walsh invited me, and a few friends, as VIP to his concert of The Eagles. Last time we did not bring a present and we felt a bit guilty. So this time Dick arranged an old Philips tube for Joe and a tile 'Delfts Blauw' to ... http://rembl.org/index.php/2008/04/18/remco-meets-joe-walsh-the-eagles-again/ Although DCF77 seems to be the 'default' time reference for the European continent, I want to have a backup because I run a stratum 0 NTP server. MSF (60 kHz England, UK) is a good candidate. Compared to DCF receivers, MSF receivers are difficult to obtain and expensive on the continent. So, ... http://rembl.org/index.php/2008/03/24/adding-msf-to-your-ntpd-refid-list-or-msf-60-khz-from-dcf-775-khz/ Yesterday I built a 10.000.000 divider with a small cascade of 74LS390's to divide the rubidium 87 (Rb87) locked 10,000.000.00000(0) MHz from my Efratom FRS into 1 Pulse Per Second (PPS). I know that there is a another approach available. However, I managed to program a 16F648A PIC, but the ... http://rembl.org/index.php/2008/02/23/rb87-experiment-with-ntpremcoorg/ In my previous post I reported a succesfull try wih LinuxPPS in conjunction with ntpd's NMEA, ATOM and SHMPPS drivers. However, as far as I could ascertain, the PPS signal from the CIROCOMM G100/300 (I still have not heard anything from them..) can not be locked to the GPS signal ... http://rembl.org/index.php/2008/02/16/rockwell-jupiter-and-linuxpps/ As many of you know, I run an 'open access' stratum 1 NTP server (ntp.remco.org) for almost four years now. In fact, ntp6.remco.org is one of the few open access IPv6 NTP servers worldwide. During this period ntpd was disciplined with a DCF77 radio module, keeping the time within a few ... http://rembl.org/index.php/2008/02/14/linuxpps-cirocomm-nmea-pps-or-dcf/ OK, here is the picture: the CQWW 160m contest and my recent experiments with K9AY-loops, of which Gary K9AY (also active during the contest!!) himself wrote: "The changes are good ideas. I also stopped using an autotransformer and do not use the +/-/AC control voltage. When I added a 3-relay termination ... http://rembl.org/index.php/2008/01/28/cqww-160m-cw-contest-with-pa7fa-and-pg0a/ 9:1 transformer During my preparations for the PACC contest I made some K9AY loops. It is generally recognized that galvanic separation of the loops and the receiving system is highly recommended to decrease interference, noise, and other strange phenomena. The original K9AY design used an 9:1 autotransformer, and voltages to switch ... http://rembl.org/index.php/2008/01/12/pg0a-implementation-of-k9ay-loops/ Yesterday I went shopping in my city and immediately heard nice sounds from the main street. A -by Hilversum standards- large crowd gathered around two guys playing astonishingly good, nice and ambient music. People tapping with their feet, children quietly listening, mothers and fathers laughing. These two guys were performing, ... http://rembl.org/index.php/2007/10/28/carlos-vamos-and-lindsey-buckland/