On 8 June 2012 13:20, Michael Baker <mp...@clanbaker.org> 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 10000 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.