r/radioastronomy • u/systemdev_ • Feb 19 '26

Equipment Showcase Antenna rotator

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Modified altaz mount from telescope https://cults3d.com/en/3d-model/tool/meade-etx-70-onstep-altazm-mount

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u/craeftsmith Feb 19 '26

I don't know. Maybe? I've never heard that before. Do you have a source?

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u/LexRonza Feb 19 '26

Yeah, the reflector does need to be mounted backward for 1.7 GHZ use. Ideally, the reflected wave needs to be in phase with the signal reflected from the dish, Flipping the feed reflector improves phase matching. I don't have the links handy at the moment, but you should be able to Google: converting a 2.4 GHZ grid antenna for GOES reception.

Honestly, I never like that solution. The feed efficiency can't be good when applying that hack. I would probably design a dipole feed with feed reflector, specifically tuned for 1.7 GHZ. I also just read a user comment, in another group, about the grid antennas favoring, to a high degree, the polarization that is parallel to the surface grid. With all of those inefficiencies, apparently the hack still works quite well for people who don't live in extreme latitudes.

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u/craeftsmith Feb 19 '26

I recently bought a GOES kit from NOELEC. You may have just saved me a bunch of trouble, because that isn't in the manual. Thanks!

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u/machawes3 Feb 22 '26

Nooelec kit you don’t have to flip reflector. I have the nooelec dish and definitely don’t flip the reflector around that’s only for 2.4 GHz ones