Jim Lux said: > Non ideal antennas make the grating lobes wiggle or be wavy along their long > axis. Of course what YOU care about are the nulls (and to a lesser extent > the phase smoothness as you traverse the pattern).  I've looked a lot of > these kind of models and your saving grace is that the nulls are deep only > when the signals from the antennas are equal strength, which doesn't really > happen much. In the case of interest, the signal strength will be strongly unbalanced. It would be interesting to plot the signal strength as a satellite goes from one receiver to the other. You could make several plots with the antennas pointed up at different angles so the field of view would overlap more or less. What do I need to combine a pair of antennas? -- These are my opinions. I hate spam.

On 7/1/23 4:03 PM, Hal Murray via time-nuts wrote: > Jim Lux said: >> Non ideal antennas make the grating lobes wiggle or be wavy along their long >> axis. Of course what YOU care about are the nulls (and to a lesser extent >> the phase smoothness as you traverse the pattern).  I've looked a lot of >> these kind of models and your saving grace is that the nulls are deep only >> when the signals from the antennas are equal strength, which doesn't really >> happen much. > In the case of interest, the signal strength will be strongly unbalanced. > > It would be interesting to plot the signal strength as a satellite goes from > one receiver to the other. You could make several plots with the antennas > pointed up at different angles so the field of view would overlap more or less. > > What do I need to combine a pair of antennas? > > > Did some sample plots in a subsequent post. You'd need a power combiner - which is just a splitter used in reverse. Depending on signal levels and whether there are LNAs on the antennas, it could be as simple as just hooking the antennas up in parallel. If you're an all passive system, then something like a Minicircuits ZX10-2-25 (or any of a dozen or more) would do. With a dB hit from the loss through the combiner. https://www.minicircuits.com/WebStore/dashboard.html?model=ZX10-2-25-S%2B

Hi If you are just trying an experiment, there are cable TV splitters from places like Lowes or Home Depot that go up to 2 GHz. You do need to look at the label on the part to be sure, they don’t all go past 1 GHz. Bob > On Jul 2, 2023, at 11:50 AM, Lux, Jim via time-nuts <time-nuts@lists.febo.com> wrote: > > On 7/1/23 4:03 PM, Hal Murray via time-nuts wrote: >> Jim Lux said: >>> Non ideal antennas make the grating lobes wiggle or be wavy along their long >>> axis. Of course what YOU care about are the nulls (and to a lesser extent >>> the phase smoothness as you traverse the pattern). I've looked a lot of >>> these kind of models and your saving grace is that the nulls are deep only >>> when the signals from the antennas are equal strength, which doesn't really >>> happen much. >> In the case of interest, the signal strength will be strongly unbalanced. >> >> It would be interesting to plot the signal strength as a satellite goes from >> one receiver to the other. You could make several plots with the antennas >> pointed up at different angles so the field of view would overlap more or less. >> >> What do I need to combine a pair of antennas? >> >> >> > Did some sample plots in a subsequent post. > > You'd need a power combiner - which is just a splitter used in reverse. Depending on signal levels and whether there are LNAs on the antennas, it could be as simple as just hooking the antennas up in parallel. > > If you're an all passive system, then something like a Minicircuits ZX10-2-25 (or any of a dozen or more) would do. With a dB hit from the loss through the combiner. > > https://www.minicircuits.com/WebStore/dashboard.html?model=ZX10-2-25-S%2B > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com

On GPS with RAW data output  - I'll use three receivers and calculate fix external with raw data.  I've bought 30 pcs of https://www.skytraq.com.tw/homesite/PX1122C_DS.pdf has all the raw data. $8.70 in quantity. Taiwan origin receiver company,  Intention is to use three together. we'll see. buy up to 100qu from their webstore navspark. They also have a recv with precision pps and programmable timing outputs and 10 MHz etc programmable https://navspark.mybigcommerce.com/content/PX1100T_DS.pdf Skytraq - I have used their Venus838 chips in production product for years. the stuff works. They've also got a range of L5 capabable devices now. On 3/07/2023 1:50 am, Lux, Jim via time-nuts wrote: > On 7/1/23 4:03 PM, Hal Murray via time-nuts wrot