Not only that, but GPS signals are way, way down in the mud. It's "normal" for the GPS signal to be below the ambient noise level. There's some very clever comb filters they use to extract the signal from the noise. That said, and additional noise would be a problem for sure.
On Thu, Aug 24, 2017 at 12:01 PM, <[email protected]> wrote: > Lotsa noise sources can. Should not be any transmitters but there are > always intermodulation products. > > *From:* Adam Moffett > *Sent:* Thursday, August 24, 2017 12:39 PM > *To:* [email protected] > *Subject:* Re: [AFMUG] ePMP GPS antenna fails > > If they just need a power cycle like George is saying then yeah I guess it > could be. > > I think GPS is 1.5ghz and 1.2ghz. What would interfere with it? > > > ------ Original Message ------ > From: [email protected] > To: [email protected] > Sent: 8/24/2017 2:12:21 PM > Subject: Re: [AFMUG] ePMP GPS antenna fails > > > Local interference? > > *From:* Adam Moffett > *Sent:* Thursday, August 24, 2017 12:03 PM > *To:* [email protected] > *Subject:* Re: [AFMUG] ePMP GPS antenna fails > > What we're seeing is GPS Status "Down". We can get it to go "Up" by > swapping the GPS antenna without rebooting. If I put the bad antenna back > on while it's still running I'll still have status "Up", but on a power > cycle it goes down again. The problem does follow the antenna. > > That's the one I have in hand. The other two "fails" could have needed a > power cycle like you're saying....I guess we'll find out. > > > > ------ Original Message ------ > From: "George Skorup" <[email protected]> > To: [email protected] > Sent: 8/24/2017 1:26:49 PM > Subject: Re: [AFMUG] ePMP GPS antenna fails > > > The ePMP GPS is just like the old 450AP's on-board GPS. You don't > necessarily need the external antenna. The GTop receivers have a built-in > antenna. Obviously the problem is they're facing at the horizon and tower > steel, etc. I have several 1k GPS for PTP links. I didn't need the GPS, > just the gigabit ethernet. They do not have the pucks attached. They're on > Rocket dishes facing into a mast and tower steel. Most of them are tracking > 14+ out of 20+ sats. I've said several times before, the newer GTop > GPS+GLONASS receivers just work better. > > If the radio is seeing no data, then the receiver is probably locked up > and you'll have to power cycle it. If you're seeing 0 tracked and maybe 0 > or a few available sats, then the receiver is confused, or it's seeing lots > of multipath or possibly noise. You can try a power-cycle first, and if > that doesn't do anything, then try moving the puck. If it's in the top of > the Cambium OEM antenna, then I guess you're kinda screwed for moving it. > > Easiest solution: SyncInjector/PowerInjector+Sync and a 'Pipe or 'Box. > > On 8/24/2017 11:49 AM, Adam Moffett wrote: > > How often do ePMP GPS antennas fail? > > We had 3 fail in the past month, so I was wondering if they have an > expected lifespan of some sort. > > > > -- -- bp part15sbs{at}gmail{dot}com
