" having around 20 dB of gain at the antenna greatly decreases the effect of feed line loss on noise figure."
And that would be consistent with usage for a timing receiver which is expected to have a well exposed antenna and a significant line length, as opposed to navigation receivers where the antenna is expected to have a short feed line. On Mon, Jul 31, 2017 at 4:17 PM, Brooke Clarke <[email protected]> wrote: > Hi Jerry: > > The Trimble is the oldest mass produced GPS receiver I know of and because > the early receivers used high gain antennas it seems that Trimble kept that > idea for the newer designs. They like about 41 dB gain between the antenna > and the input to the receiver. > http://www.prc68.com/I/Trimpack.shtml#Ant > Newer designs probably place that gain in the front end rather than at the > antenna. But having around 20 dB of gain at the antenna gretly decreases > the effect of feed line loss on noise figure. > > -- > Have Fun, > > Brooke Clarke > http://www.PRC68.com > http://www.end2partygovernment.com/2012Issues.html > > > -------- Original Message -------- > >> Due to access problems, I run my Thunderbolt with a Symmetricom 58532A >> antenna placed indoor near a window facing South… can’t get much worse but >> most of the time it will be locked onto 3 or 4 satellites. I recently >> bought a www.leobodnar.com <http://www.leobodnar.com> GPSDO for my SDR >> ham >> radio setup. I was very surprised to find that this minimalist GPSDO >> using >> a small patch antenna with internal LNA placed near my window had >> satellite >> & PPL lock within a few seconds. It requires 3-4 satellite locks for its >> PPL. However, when I attached the patch antenna to my Thunderbolt – >> satellite signal strength were zero or minus for all satellites. The >> specs >> for the patch antenna are listed below. >> >> >> I would appreciate any advice understanding this behavior. >> >> >> Jerry NY2KW >> >> >> Center Frequency 1575.42MHz±3 MHz >> >> V.S.W.R 1.5:1 >> >> Band Width ±5 MHz >> >> Impendence 50 ohm >> >> Peak Gain >3dBic Based on 7×7cm ground plane >> >> Gain Coverage >-4dBic at –90°<0<+90°(over 75% Volume) >> >> Polarization RHCP >> >> LNA/Filter >> >> LNA Gain (Without cable) 28+/-3dB >> >> Noise Figure 1.5dB Typ. >> >> Filter Out Band Attenuation (f° =1575.42MHz) >> >> 7dB Min f0+/-20MHZ >> >> 20dB Min f0+/-50MHZ >> >> 30dB Min f0+/-100MHZ >> >> V.S.W.R <2.0 >> >> DC Voltage 2.7V/3.0V/3.3V/5.0V/3.0V to 5.0V/other >> >> DC Current 5mA /11mA/15mA Max >> >> >> >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to https://www.febo.com/cgi-bin/m >> ailman/listinfo/time-nuts >> and follow the instructions there. >> >> > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/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.
