Re: [time-nuts] Monitoring the Rapco 1804M - how antenna changesaffect the unit
Hi Rob I picked up a couple of mushroom shaped (white flat top rounded edges prob 70mm diam.) antennas with a small right-angle bracket and a TNC connector (5v supply) no nameplate but they seem to work fine on 20 feet of RG-58. The manual for the 1804M says its an 8-channel receiver and I recollect it being a Trimble. Alan G3NYK - Original Message - From: Robin Kimberley robkimber...@btinternet.com To: jleik...@leikhim.com; 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Wednesday, November 02, 2011 9:01 PM Subject: Re: [time-nuts] Monitoring the Rapco 1804M - how antenna changesaffect the unit The ET6000 used Trimble Bullet antennae when I was selling them in the UK. I seem to remember about 35db of gain in that antenna. Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Joe Leikhim Sent: 02 November 2011 18:52 To: time-nuts@febo.com Subject: [time-nuts] Monitoring the Rapco 1804M - how antenna changes affect the unit I tried a similar Garmin antenna with my Datum ET6000 and the lock times were really long, even with the antenna on a 14 foot pole above the roof. I attribute a lot of this to the long 8 ft RG174 style coax pigtail. I have to wonder if the gain of the preamp as published actually includes the inherent cable loss, and even if so the preamp must be screaming in gain to make up for the loss. I intend to get a proper antenna. Here is a comparison of specs of these type antennas: http://gpsinformation.net/main/gpsantrev1.htm -- Joe Leikhim Leikhim and Associates Communications Consultants Oviedo, Florida www.Leikhim.com jleik...@leikhim.com 407-982-0446 WWW.LEIKHIM.COM ___ 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.
Re: [time-nuts] Monitoring the Rapco 1804M - how antenna changesaffect the unit
re my last, suggesting it was an 8ch GPS.. I have just realised I was looking at the Rb version manual not the OCXO version which does have a 6ch receiver. (at least on the manual version I have ) apologies ...put brain in gear before etc. Alan G3NYK - Original Message - From: Robin Kimberley robkimber...@btinternet.com To: jleik...@leikhim.com; 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Wednesday, November 02, 2011 9:01 PM Subject: Re: [time-nuts] Monitoring the Rapco 1804M - how antenna changesaffect the unit The ET6000 used Trimble Bullet antennae when I was selling them in the UK. I seem to remember about 35db of gain in that antenna. Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Joe Leikhim Sent: 02 November 2011 18:52 To: time-nuts@febo.com Subject: [time-nuts] Monitoring the Rapco 1804M - how antenna changes affect the unit I tried a similar Garmin antenna with my Datum ET6000 and the lock times were really long, even with the antenna on a 14 foot pole above the roof. I attribute a lot of this to the long 8 ft RG174 style coax pigtail. I have to wonder if the gain of the preamp as published actually includes the inherent cable loss, and even if so the preamp must be screaming in gain to make up for the loss. I intend to get a proper antenna. Here is a comparison of specs of these type antennas: http://gpsinformation.net/main/gpsantrev1.htm -- Joe Leikhim Leikhim and Associates Communications Consultants Oviedo, Florida www.Leikhim.com jleik...@leikhim.com 407-982-0446 WWW.LEIKHIM.COM ___ 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.
