Hi I'm not sure that the "real" application here is a GPSDO. If it is, then holdover may well be the easy answer.
Bob On Apr 8, 2013, at 6:29 PM, Mark Spencer <[email protected]> wrote: > In my experience in the northern hemisphere if the window is more or less > south facing and the window isn't coated with something that absorbs RF > energy then an antenna located inside and near the window will frequently > (but not always) provide enough signal for a GPS timing receiver to work but > it may go into "hold over" from time to time. I'd be inclined to try an > inside antenna before spinning my wheels on other solutions. > > As another approach, consider that if the GPS receiver can opperate from > external DC power or you can arrange for a UPS to power the GPS receiver and > it provides a "hold over" mode you could connect the GPS receiver to a > suitable antenna at another location then run it in "hold over" mode while > moving it inside. The GPS receiver specs should provide insight into the > accuracy you will get while in "hold over" but physically moving the GPS > receiver will likely add some additional error unless the receiver was > designed for use on moving platforms. > > If you simply need a single reference source to enable a demo or a conference > for a limited period of time then the absolute accuracy might not matter much > ? > > Good luck and best regards > Mark Spencer > >> >> Message: 7 >> Date: Mon, 8 Apr 2013 22:29:43 +0100 >> From: "Alan Melia" <[email protected]> >> To: "Discussion of precise time and frequency measurement" >> <[email protected]> >> Subject: Re: [time-nuts] GPS antenna?? >> Message-ID: <2E167F4F56A9450B83CC23F01F8BB523@gnat> >> Content-Type: text/plain; format=flowed; >> charset="iso-8859-1"; >> reply-type=response >> >> Hi David yes its ferro-concrete which makes quite a good >> screen (a lot worse >> than domestic brick) but the windows are not coated I think. >> (BT Labs at >> Martlesham) >> >> Thanks all for some thought stimulating ideas .....GPSDO >> outside might not >> be too easy....1U rack case mains powered....no power >> available outside but >> 10MHz (or 5MHz in this case) coupling through wall or window >> is a lot easier >> if I had a battery powered unit.....I have a feeling there >> may be battery >> back-up terminals on it must get the book out. >> >> The windows are SW I think but give a good view of a >> quadrant of the sky. It >> will be interesting to see how long it takes to lock up >> compared with an >> outside antenna. >> >> Thanks and Best Wishes >> Alan >> G3NYK >> >> >> > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
