Saveitforparts Checks out the Discovery Dish
Over on his YouTube channel 'saveitforparts,' Gabe has uploaded a video checking out and reviewing our Discovery Dish product that we successfully crowd-funded on CrowdSupply back in December 2023.
Discovery Dish is designed as a low-cost way to dive straight into backyard satellite experiments, including receiving L-band and S-Band weather satellites as well as Inmarsat satellites. It also offers an easy entry into making galactic Hydrogen line observations.
The dish is a 70cm prime focus dish, that can easily be broken down into three parts for easy storage and transport. The feeds are fully integrated, meaning that the feed antenna, LNA, and filtering are all in one unit and built into a waterproof enclosure. This means there is no need to purchase individual components and figure out waterproofing.
In his video, Gabe unboxes the Discovery Dish, builds it, and uses the L-band feed to receive a few images from GOES 16, Meteor M3, Meteor M4, and METOP weather satellites. He goes on to successfully test reception with the S-band feeds on NOAA weather satellites, before testing out the Inmarsat feed and successfully receiving signals. Finally, Gave notes that he hopes to test out the Hydrogen Line feed in a future video.
1)It’s an over priced dish, I can find free dish left outside just walking around my streets.
2)Linear feed, for circularly polarized signals is not good.
3)It’s gonna break in the wind just wait til the first storms to trigger the return process, several have already cracked in post.
4)It’s not portable. It’s a big dish. It’s going to take up half your garage space when you need to store it.
5)Dong! Dong! Dong! Loud noises whenever you are screwing it together or taking apart, or carrying it around.
6)L-Band feed performs poorly for a $200 feed looking at the lines in the final images.
7)S-Band feed is even poorer, it only covers a a tiny frequency range for NOAA sats which you might as well use L-Band for.
8)Hydrogen Line feed is boring, probably an attempt to steer the hacker crowd away from the exciting stuff (actual satellites).
9)Inmarsat feed is not needed on a dish, a simple cheap rhcp helical feed pointed directly at the satellite is totally enough.
10) Those hundreds of tiny holes increase wind drag, and likely going to end in failure in a storm.
11)Too much cable, cable too thick, too much bolting and screwing parts together, Not portable as other options out there.
12)Having to remove the end feed reflector everytime you pack away a feed is a chore and is poor design.
13)Won’t be carrying it up a mountain or through the streets, it’s just going to stay at home in the garage. There are more portable options.
14)Can’t use your own LNA with any of the feeds, and can’t daisychain filters or bandstops/passes as the pcb lna is fixed and non-bypassable.
15)*Bong-Bong-Bong! Noises*
Interesting ‘review’.
How long have you had yours? What modes are you using it for?
Thanks for the review. I’d like to make a few rebuttal points:
1) Obviously, if you can find your own dish and can DIY a feed, that is good for you, but if you want to avoid dumpster diving and excessive DIY, and just get straight into the project, then this is the product for that. To each their own.
2) CP<->LP is a 3dB loss, which isn’t ideal, but the signal is strong enough anyway without those extra 3 dB. The linear feed allows it to be used with weaker linear polarized geosats that need a matching linear polarized feed with this dish size, while still allowing it to be used with polar orbiting circular polarized sats that typically have stronger signals that don’t mind the 3dB loss.
3) We haven’t had any return requests so far and only saveitforparts one was cracked, probably because it went back and forth in the couriering process a few times. Obviously, it’s designed as a light-weight portable backyard dish, so it should be taken down during a hurricane. But it will survive in normal weather conditions.
4) It’s definitely a lot easier to manage than a dish that can’t be broken down. The shipping/storage box is 25.2 x 16.5 x 3.9 inches (64 x 42 x 10 cm). Nowhere near half a garage.
5) I don’t really understand your point? Anything metal is going to go dong if you hit it.
6) The signal strength is sufficient for perfect images when aligned correctly.
7) The frequency range covers most S-band satellites of interest. S-band downlinks on most satellites are very region dependent. An S-band feed is a niche community request that we decided to cover.
8) I don’t see why it’s not okay for other people to have different interests? There’s a lot that can be done in amateur radio astronomy, and if DD helps introduce a few to that hobby then that’s good.
9) The Inmarsat feed was requested by a few members of the community, so we thought why not produce a few units for those who need the extra few dB. The circuit and feed design allows us to easily make band changes without a large redesign.
10) The holes will not increase wind drag. The holes are for wind, water drainage and weight. Yes, the holes are not effective at high wind speeds, just like any other dish.
11) LMR200 isn’t that thick. Most people have requested a sufficient cable length to get the signal into the house. If you’re worried about loss, don’t be, as the LNA provides plenty of gain to overcome the cable losses and not reduce the NF. The bolting takes 10 minutes. What other options do you recommend?
12) It’s a minor inconvenience, but feel free to offer a redesign idea for a future revision.
13) That’s up to the individual person. It’s primarily designed to be a backyard experimenter dish.
14) If you’re wanting to use your own custom setup, this is of course not the dish for you. This is designed to be a dish that can introduce you to the hobby quickly, and it already has a nice low NF, filtering and sufficient gain, so there is no need to add anything else in 99% of situations.
15) ???
If you’d like to read a review of the dish and see how it compares with the patch antenna.
https://community.airframes.io/t/discovery-dish-rtlsdr-blog-l-band-acars/181
Thanks for the excellent Discovery Dish demo and explanation.
Receiving GOES18 with this dish and a PI. Already proved to the kids the earth is a round flat disk with the images I’ve received directly from the satellite. Also we can see when it might rain.