Thanks for the responses. It looks similar to but not exactly like the two antennas referenced. They say the preamp is 3 to 5.5 volts, whereas the eBay antenna says its preamp is good from 3.3 to 18 volts, indicating I can run it off 12 volts. Regarding the internals, I must have somehow missed the photo which clearly shows it to be a patch antenna. It looks pretty similar to the Trimble I asked about recently, inside, that is. That Trimble had been dropped from a great height. The nylon screws that hold the actual antenna assembly had all been broken. I ordered new ones and replaced them. Disassembly was easy, reassembly not so much. Mine was made to have the groundplane, but doesn't have it. I suspect that since I am not doing surveying, it won't matter all that much. I bought an adapter for the 5/8 by 11 thread it uses and have a pvc pipe mount ready to go up. My location is not ideal. It will be atop a 40 foot Rohn 25 tower, but there are tall trees nearby. Since my Z3801 died, I don't have much of a GPSDO to use the antenna with. Just a couple of T bolts and some kind of postcard sized unit I need to build a housing and power supply for. Still, enough to experiment with.

Hi There is no need for something this exotic for L1 only reception. It *is* nice to have Glonass L1, but that’s about the extent of how fancy you need to go. As noted in another post, the preamp gain probably is pretty high on this antenna. That’s a standard that goes back to the early days of Trimble survey GPS gear. It’s great if you happen to want to drive a 32 port resistive splitter for your collection of GPSDO’s. If you have more modest needs for splitting, pads would be a very good idea. Bob > On Feb 6, 2018, at 8:08 AM, John Green <wpxs472@gmail.com> wrote: > > Thanks for the responses. It looks similar to but not exactly like the two > antennas referenced. They say the preamp is 3 to 5.5 volts, whereas the > eBay antenna says its preamp is good from 3.3 to 18 volts, indicating I can > run it off 12 volts. Regarding the internals, I must have somehow missed > the photo which clearly shows it to be a patch antenna. It looks pretty > similar to the Trimble I asked about recently, inside, that is. That > Trimble had been dropped from a great height. The nylon screws that hold > the actual antenna assembly had all been broken. I ordered new ones and > replaced them. Disassembly was easy, reassembly not so much. Mine was made > to have the groundplane, but doesn't have it. I suspect that since I am not > doing surveying, it won't matter all that much. I bought an adapter for the > 5/8 by 11 thread it uses and have a pvc pipe mount ready to go up. My > location is not ideal. It will be atop a 40 foot Rohn 25 tower, but there > are tall trees nearby. Since my Z3801 died, I don't have much of a GPSDO to > use the antenna with. Just a couple of T bolts and some kind of postcard > sized unit I need to build a housing and power supply for. Still, enough to > experiment with. > _______________________________________________ > 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.

		Attila Kinali

On Tue, 6 Feb 2018 07:08:42 -0600 John Green <wpxs472@gmail.com> wrote: > Thanks for the responses. It looks similar to but not exactly like the two > antennas referenced. They say the preamp is 3 to 5.5 volts, whereas the > eBay antenna says its preamp is good from 3.3 to 18 volts, indicating I can > run it off 12 volts. I am pretty sure that this is either a mistake or a deliberate deceit. Most LNA's I am aware of work between 3.3V and 5V. The cheap ones are definitely all in that range. Some of those might work for a short time with higher voltage, depending on the actual semiconductor process used for production. But that means using those chips outside their specs and putting a high straign on the semiconductor, which will lead to an early death. It also cannot be an LDO inside the antenna, as 3.3V is pretty much the lowest voltage you can get an LNA for. There are some that work at 3.0V still, but that would leave only 0.3V for the LDO, which requires a more expensive LDO. I am pretty sure there are some LNAs that work at 2.5V or even lower, but those would be definitely in the way-too-expensive category. So, my guess is, they tested the antenna whether it works with 12V, seen that it does, and just "adjusted" the specs. But in reality, the LNA still maxes out at 5V if you want a reliable device. Attila Kinali -- <JaberWorky> The bad part of Zurich is where the degenerates throw DARK chocolate at you.