[time-nuts] I wish to shorten GPS antenna cable - should I let receiver find the position again?
I have an HP 58503A which I am using as a frequency source only - not to tell the time. I want to shorted the antenna cable a bit, but are wondering if I should let the GPS receiver finds it position again. Or either of the following better * Remove antenna cable, put a new N plug on, and screw it back in with the receiver kept powered up all the time. * Power off GPS receiver and power it back on with the cable connected. I'm not moving the antenna, so the actual position will not change, but of course the signals will get to the receiver a bit sooner. Dave, G8WRB ___ 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] I wish to shorten GPS antenna cable - should I let receiver find the position again?
Le 23 avr. 2015 à 14:03, Dr. David Kirkby (Kirkby Microwave Ltd) drkir...@kirkbymicrowave.co.uk a écrit : I have an HP 58503A which I am using as a frequency source only - not to tell the time. I want to shorted the antenna cable a bit, but are wondering if I should let the GPS receiver finds it position again. Or either of the following better * Remove antenna cable, put a new N plug on, and screw it back in with the receiver kept powered up all the time. * Power off GPS receiver and power it back on with the cable connected. I'm not moving the antenna, so the actual position will not change, but of course the signals will get to the receiver a bit sooner. Just reconfigure the cable delay according to its new length. IIRC is 58503A uses the same SCPI command set last the Z3801A, so if that is the case that would be the command: :ptime:gpsystem:adelay nanoseconds NS Dave, G8WRB ___ 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. Ceux qui sont prêts à abandonner une liberté essentielle pour obtenir une petite et provisoire sécurité, ne méritent ni liberté ni sécurité. Benjimin Franklin ___ 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] I wish to shorten GPS antenna cable - should I let receiver find the position again?
Yes. You will get same location. Some GPS time receivers have cable length compensation for 1PPS output. Remember 1 foot is about 1 nano second error in 1PPS. Tim On Apr 23, 2015 1:15 PM, Dr. David Kirkby (Kirkby Microwave Ltd) drkir...@kirkbymicrowave.co.uk wrote: I have an HP 58503A which I am using as a frequency source only - not to tell the time. I want to shorted the antenna cable a bit, but are wondering if I should let the GPS receiver finds it position again. Or either of the following better * Remove antenna cable, put a new N plug on, and screw it back in with the receiver kept powered up all the time. * Power off GPS receiver and power it back on with the cable connected. I'm not moving the antenna, so the actual position will not change, but of course the signals will get to the receiver a bit sooner. Dave, G8WRB ___ 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] I wish to shorten GPS antenna cable - should I let receiver find the position again?
I agree, used only for frequency reference you won't know the difference. Still, to join the rank of true time (not just frequency) nuts, you can configure the antenna cable delay! Many (all?) of the HP GPS-based smartclock units use the command :GPSYSTEM:REFERENCE:ADELAY to compensate for the antenna length delay. After changing cable length, configure it as shown on page 1-22 of http://www.leapsecond.com/museum/hp58503a/097-58503-12-iss-1.pdf Tim N3QE On Thu, Apr 23, 2015 at 8:03 AM, Dr. David Kirkby (Kirkby Microwave Ltd) drkir...@kirkbymicrowave.co.uk wrote: I have an HP 58503A which I am using as a frequency source only - not to tell the time. I want to shorted the antenna cable a bit, but are wondering if I should let the GPS receiver finds it position again. Or either of the following better * Remove antenna cable, put a new N plug on, and screw it back in with the receiver kept powered up all the time. * Power off GPS receiver and power it back on with the cable connected. I'm not moving the antenna, so the actual position will not change, but of course the signals will get to the receiver a bit sooner. Dave, G8WRB ___ 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] I wish to shorten GPS antenna cable - should I let receiver find the position again?
On Thu, Apr 23, 2015 at 5:03 AM, Dr. David Kirkby (Kirkby Microwave Ltd) drkir...@kirkbymicrowave.co.uk wrote: I have an HP 58503A which I am using as a frequency source only - not to tell the time. I want to shorted the antenna cable a bit, but are wondering if I should let the GPS receiver finds it position again. Or either of the following better * Remove antenna cable, put a new N plug on, and screw it back in with the receiver kept powered up all the time. * Power off GPS receiver and power it back on with the cable connected. I'm not moving the antenna, so the actual position will not change, but of course the signals will get to the receiver a bit sooner. If the goal is minimizing downtime and duration of degraded quality output, I would go with the former. The 58503A will enter holdover mode. It will keep its oven warm and retain its learned oscillator model parameters. When you reconnect the antenna it will pick right back up where it left off, with minimal settling time. Henry ___ 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.
