Some basic questions about LNA's etc

[Marijn]

Dear Astronomers,

I am in the process of designing a foldable Dish radio telescope, and currently I am running into some trouble concerning the electronics behind this concept. As an amateur in this area, I fist stumbled across the Itty Bitty Telescope, which uses a LNB coubled to a Satfinder.

The main thing I like about this concept is it's simplicity, and it gives more than enough possibilities for what I want to be able to do with my dish at the moment, simple analoge drift scans. However, I am designing a larger dish than a normal TV dish, and I would like to be able to make readouts of the Hydrogen Line. This is where my question emerged.. ordinary Sat finders have ranges from 950 Mhz up to 2000 Mhz, with the H line lying in between.

So... if I would make a Cantenna feed designed for 1420 Mhz, couple it to a Commercially available 1420LNA, can I than couple the Satfinder directly to the LNA(maybe with a diode in between)

To my guessing this is too simple otherwise people allready would have done it... but I can't seem to figure out why this wouldn't work if the same concept works for a LNB with a frequency output within the same range of the Satfinder.

BTW, here is a preliminary sketch of my dish, it's allready outdated, I realised it's better to go for a mesh type dish, I would also change the mount and the Canfeed.

Best regards,

Marijn