немного из творчества K5DN:
Bob k5dn_bob@yahoo.com
is experimenting with 3 cm reception
I have a cheap Ku band "LNB" just stuck in the throat of my 23 cm horn on a piece of plywood.
It's LO is at 9.75 GHz, which gives an IF out at 618 MHz. This feeds a hodge - podge down converter to 50 MHz in my EME
cabinet at the base of the dish. The 50 MHz signal is fed by coax back to the shack (a couple hundred feet away) and
into a Flex 6400 in shack. It actually works better than expected, although sun noise is rather low for my dish size;
about 8 dB. The LNB LO is xtal controlled, but not stabilized in any way, so it drifts around noticeably. Sometimes digital
signals look quite nice, but I get few decodes. Other times, I see several decodes in a row. I started working on this
project after reading about amateur reception of 8.4 GHz Deep Space vehicles. There's a lot of material written about
the use of the cheap LNB's. I built up a copper CP horn (SM6FHZ design similar to my 23 cm horn) with a chopped
up LNB (model PLL321S) stuck on the side. My trackingsystem is not quite up to the task. I have to re
adjust offsets now and then, and need a better elevation sensor. I am still
deciding if l will pursue EME on 3 cm.
