I bought a GPS antenna. It was a great deal on an excellent antenna. I didn't look at the physical size. 386DX for scale.

@mxshift indisputably a very nice GPS antenna

@mxshift whoah, what the hell is all of that material for?

@dysfun it's mostly a radome. The antenna is a milled plate that is a few inches tall.

@mxshift @dysfun
Very nice.
Got any pictures of the insides?
Leica makes it sound survey-grade.

@ftg @mxshift @dysfun inb4 its some fancy jam resistant CRPA

@azonenberg @mxshift @dysfun
That's why I asked.
But rusty screws and Leica make me think it's just a very nice multiband one with some nice choke rings.

Like this Novatel.

@ftg @mxshift @dysfun not sure if it's exactly the same one, but their product page has some RF-looking magic: https://leica-geosystems.com/products/gnss-reference-networks/antennas/leica-ar25 .

@ftg @dysfun the center cap is glued down so no further disassembly

@mxshift @dysfun
Thank you for the picture.
Unfortunate that the main element does not open.
As everybody seems to just call it "Dorne-Margolin antenna element" or "a Dorne & Margolin C146-10 vertical dipole element".
And Dorne & Margolin seems to be some company.

@ftg @mxshift @dysfun https://sites.calian.com/app/uploads/sites/8/2023/11/Tallysman-Intergeo-2020.pdf

@mxshift Now you simply need to buy 737, because that's apparently what it is designed for :-). (Just kidding, it is probably for yacht?)

@pavel it's a survey antenna for fixed location reference stations. I'm using it to get high accuracy on timing for disciplining a rubidium clock

@k5em @mxshift @dysfun
Nice find, thanks.
So that Dorne Margolin setup is 4x phased, tilted dipoles?

@ftg @mxshift @dysfun that is what the schematic seems to say, but I'm actually not completely sure now, after a lot more research. Everyone regurgitates the same schematic image, but the best image I've found of it is this one from https://carleton.scholaris.ca/bitstreams/52972888-15b0-48e4-a962-c3af09b38cc2/download

@k5em @mxshift @dysfun
Strange that there are also no references to patents and patent numbers.

@ftg @mxshift @dysfun agree. There's the original Alford loop patent, but it doesn't really reflect what seems to be going on here, even though the D&M is called a modified Alford loop. https://patents.google.com/patent/US2283897A/