Re: [time-nuts] Procom GPS4 quadrifilar antenna...
On 8 June 2012 13:20, Michael Baker wrote: > Time-nutters-- > > The Procom website lists the noise-figure of their quadrifilar > LNA as: > > GAIN > 30 dB > NOISE FIGURE < 3 dB (incl. input filter). > Typ. approx. 3 dB > > > I am a little surprised at this relatively high NF for a > product in this price category. Even most low-end > mass-produced consumer grade GPS antennas are > spec'd at 1.5 to 2.0 dB NF. > > Mike Baker I know at least in antennas, consumer and at low/mid end professional products rarely meet their specs.Even SWR, which is fairly easy to measure is often not met on antnenas. Gain is never measured - the figures are just made up. It seems everyone lies, and needs to lie to remain in business. Just look on eBay and see some of the redicusly high gains for some antennas, where the sellers has a feedback of 1 and 99.9% positive. Of course, for radio hams, dramatic lies about the SWR would be detected, but gain figures are unlikely to be challenged. That said, I don't undeerstand how something can have a spec of < 3dB NF, then have a typical noise figure of approximately 3 dB. But I bet a lot of manufactures of GPS antennas have the NF of their device being that of the amplifier chip they use, and all losses, like those of filtering, are ignored. Dave ___ 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.
Re: [time-nuts] Procom GPS4 quadrifilar antenna...
That would be great. Softball tournament on Saturday in Newbury Park , JPL openhouse Sunday. --- On Fri, 6/8/12, Jim Lux wrote: From: Jim Lux Subject: Re: [time-nuts] Procom GPS4 quadrifilar antenna... To: time-nuts@febo.com Date: Friday, June 8, 2012, 1:26 PM On 6/8/12 9:21 AM, steve heidmann wrote: > Is it worth driving from Thousand Oaks to Altadena for Snowcones (qty 5) > tomorrow ? > > --- On Fri, 6/8/12, Jim Lux wrote: > http://www.jpl.nasa.gov/events/open-house.cfm Well.. they've got all the stuff setup for JPL open house.. Is it worth an hour's drive? The weather is nice. There's lots of MSL related stuff out. If you have little kids, there's the usual "drive a rover over a row of children" thing. I don't know if the totally cool Athlete rovers will be out. Hopefully yes. The Mars Yard is always fun, and they'll have something out crawling around. http://www.jpl.nasa.gov/video/index.cfm?id=922 Will there be tours of the frequency and timing lab? (which would be of particular interest to time-nuts).. nope.. But, if you're in the area some other time, send me a note, and I'll see what I can do. Down in my lab, we don't have anything nearly as good as what they've got up there. (but they send me their maser derived reference on a fiber optic pipe...) ___ 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.
Re: [time-nuts] Procom GPS4 quadrifilar antenna...
On 6/8/12 9:21 AM, steve heidmann wrote: Is it worth driving from Thousand Oaks to Altadena for Snowcones (qty 5) tomorrow ? --- On Fri, 6/8/12, Jim Lux wrote: http://www.jpl.nasa.gov/events/open-house.cfm Well.. they've got all the stuff setup for JPL open house.. Is it worth an hour's drive? The weather is nice. There's lots of MSL related stuff out. If you have little kids, there's the usual "drive a rover over a row of children" thing. I don't know if the totally cool Athlete rovers will be out. Hopefully yes. The Mars Yard is always fun, and they'll have something out crawling around. http://www.jpl.nasa.gov/video/index.cfm?id=922 Will there be tours of the frequency and timing lab? (which would be of particular interest to time-nuts).. nope.. But, if you're in the area some other time, send me a note, and I'll see what I can do. Down in my lab, we don't have anything nearly as good as what they've got up there. (but they send me their maser derived reference on a fiber optic pipe...) ___ 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.
Re: [time-nuts] Procom GPS4 quadrifilar antenna...
Is it worth driving from Thousand Oaks to Altadena for Snowcones (qty 5) tomorrow ? --- On Fri, 6/8/12, Jim Lux wrote: From: Jim Lux Subject: Re: [time-nuts] Procom GPS4 quadrifilar antenna... To: time-nuts@febo.com Date: Friday, June 8, 2012, 6:23 AM On 6/8/12 5:20 AM, Michael Baker wrote: > Time-nutters-- > > The Procom website lists the noise-figure of their quadrifilar > LNA as: > > GAIN > 30 dB > NOISE FIGURE < 3 dB (incl. input filter). > Typ. approx. 3 dB > > > I am a little surprised at this relatively high NF for a > product in this price category. Even most low-end > mass-produced consumer grade GPS antennas are > spec'd at 1.5 to 2.0 dB NF. > One thing to check on NF specs is the temperature range over which they are valid. A "consumer" spec might be "at room temperature only", a more rigorous spec might be "at -20 to +50C". ___ 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.
Re: [time-nuts] Procom GPS4 quadrifilar antenna...
On 6/8/12 5:20 AM, Michael Baker wrote: Time-nutters-- The Procom website lists the noise-figure of their quadrifilar LNA as: GAIN > 30 dB NOISE FIGURE < 3 dB (incl. input filter). Typ. approx. 3 dB I am a little surprised at this relatively high NF for a product in this price category. Even most low-end mass-produced consumer grade GPS antennas are spec'd at 1.5 to 2.0 dB NF. One thing to check on NF specs is the temperature range over which they are valid. A "consumer" spec might be "at room temperature only", a more rigorous spec might be "at -20 to +50C". ___ 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.
Re: [time-nuts] Procom GPS4 quadrifilar antenna...
Time-nutters-- The Procom website lists the noise-figure of their quadrifilar LNA as: GAIN > 30 dB NOISE FIGURE < 3 dB (incl. input filter). Typ. approx. 3 dB I am a little surprised at this relatively high NF for a product in this price category. Even most low-end mass-produced consumer grade GPS antennas are spec'd at 1.5 to 2.0 dB NF. Mike Baker -- ___ 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.
