My problem is I am using a Motorola antenna with 24 db of gain, looking at Trimble they expect 35 db gain.
I am in an apartment and the management let me put up a GPS antenna on the edge of the roof. I came down with 20 feet of RG6 and then jumped into RG59 coax to run inside the apartment. I "guesstimate" there is 40 to 60 feet in the RG59 run. I added a cheap DSS amplifier at the GPS splitters and its improved. I am going to look into moving the amp to where the coax comes into the building , the RG6/RG59 junction - but I will need to figure out a bias tee scheme to feed 12 volts to the DSS amp, and then I need to take it out and bias the antenna at +5 volts. Brian - KD4FM Mark Sims wrote: > The Thunderbolt does not seem to be the most sensitive receiver around, but > it does not seem particularly bad. Sensitivity in a time receiver can be a > bad thing... more sensitivity tends to make it more susceptible to > multipath, etc. These things were meant to be mounted on cell towers, etc > where they have a pretty clear view of the sky. Once you have that, you > don't need high sensitivity. Also their proximity to high power RF > transmitters makes overly sensitive front ends a problem. > > On the subject of GPS amplifiers... adding external amplification to a GPS > may not improve its performance and can actually degrade it. All amplifiers > amplify signal and noise, plus distort everything in the process. > (fundamental laws of the universe: 1) You can't get something for nothing, > 2) You can't break even, 3) You'll die trying) Ideally, you want the > amplifier at the antenna and you want the amplification to match the cable > loss and no more. Generally GPS receivers with poor sensitivity have poorly > designed front ends or signal processing. Yelling in their ears won't make > them work any better. > ---------------------------------------- > > _________________________________________________________________ > Get ideas on sharing photos from people like you. Find new ways to share. > http://www.windowslive.com/explore/photogallery/posts?ocid=TXT_TAGLM_WL_Photo_Gallery_082008 > _______________________________________________ > 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.
