Hi Are all the receivers the same type / model? If so what are they? Various receivers made over the last 20 years have some “issues” that can pop up.
Is the antenna gain properly matched to the needs of the receiver? Some are designed for a “target gain” of 20 db, others 30, some 50. Match a 20 db receiver with a 50 db antenna …. you have issues. Are all the hilltops in common view of each other? Somebody jamming their ankle bracelet could be the simple answer if they are …. Just what overloads this or that receiver often is a bit obscure. Most are pretty good at taking out CW tones. It often takes something a bit more complex to drive them insane. This makes testing a bit exciting. Lots of strange and weird possibilities. Bob > On Jul 10, 2022, at 3:19 PM, skipp Isaham via time-nuts > <[email protected]> wrote: > > Hello to the Group, > > I'd like to get some opinions and war stories regarding GPS reliability at > high RF level and elevation locations. > > Background: Three different hill-top GPS receivers, all different types, > using > different antennas mounted on an outside fixiture, plain view of the open > sky, > all stopped working. > > Test antennas were brought in and placed on a fixture well away from the > original antennas, the recevers went back in to capture and lock. > > From what I understand, the original antennas are what I would call straight > preamp with no pre-selection / filtering. > > The ordered and now inbound replacements are said to contain a SAW filter > system. It is the intent of the client to just place these "improved > antennas" in > to service and get on with life. > > I would suspect a GPS antenna (and receiver) could be subject to RF overload > or blocking, however, we're assuming nothing major has changed at the site, > nor > any nearby location. One might think there are more GPS receivers being > pushed > out of reliable operation by the world around them, I'm just not hearing > those stories > from a lot of people using them (GPS receivers). > > Any new install GPS receiver antenna ordered will/should contain some > pre-selection > to potentially avoid a problem, even some years down the road? Seems like > that's > where things are going... no more off the shelf, wide band, (hot) > preamplified GPS antennas > in busy locations? > > Thank you in advance for any related comments and/or opions ... > > cheers, > > skipp > > skipp025 at jah who dot calm > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe send an email to [email protected] _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe send an email to [email protected]
