Hi Will there be an effect? Yes. Are roughly 99% of all GPSDO’s run with antennas mounted that way by “pros” ? Yes again.
If you are setting up a reference site for high precision survey work, don’t do it that way. For a GPSDO, you should be fine. Bob > On Jun 16, 2017, at 1:17 PM, Dan Kemppainen <d...@irtelemetrics.com> wrote: > > Hi All, > > Fair Warning: Nuts Mode Engaged. :) > > > Recently we've moved to a new house and am in the process of getting the > antennas back up for various things. One of these is the GPSDO(s), and an > obvious location is somewhere on a Roan 25 tower set up just south of the > house. At about half way up the tower, there is clear sky view in all > directions and the GPS antenna is temporarily parked there about a foot off > the tower. The GPS antenna is on the south side of the tower and we're ~47N, > so most of the GPS birds should be visible. Single band GPS antenna, nothing > special. > > My guess is this will be fine. However, I'm still wondering what sorts of > multi-path or reflections could be expected off the tower itself. And are > these enough to worry about? If there is multi-path what sorts of things > would help prevent this? (Mounting the antenna further off the tower, etc.) > > Once I get the tower guy lines redone, I'm thinking about putting the GPS > antenna on the tip of the mast (No rotator on this tower). That's at about 75 > feet with nothing close by. That would be slightly above the tree line, with > a 360 degree sky view. > > FYI, currently the GPS antenna wire is "Priority Wire and Cable" RG-6/U. Did > some measurements last night. It measures as 85 Ohm, with a velocity factor > of ~.86. It looks pretty lossy, but it should still work. > > Any ideas and comments welcome! > > Thanks, > Dan > > _______________________________________________ > 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.
