|If you have a large enough dish (or a modest-sized dish and enough power at 1.2 GHz, that is, alot more than 10W), then you might be able to use one dish for both uplink and downlink for AO-40. W0LMD did a nice design for patch feeds at the main frequencies used by AO-40. While his descriptions may be sufficient for an experienced builder to put one together, I found his instructions for the LS patch feed hard to follow, to the degree that I think it discourages most people from trying. Here's some alternative pictorial instructions for his LS patch feed which require only ordinary hand-tools, aside from a 1" Greenlee chassis punch (octal tube socket size) or 1" hole saw for soft metal. Most dimensions seem to be non-critical.|
Consider building a low tech. mount for a WB4APR portable dish or similarly sized dish. This is made out of lumber instead of copper tubing and using 'armstrong' rotor (e.g. operate by hand, tune by ear), and so is very easy to build. Once this works for you, then you'll have the incentive to move on to a more sophisticated receiving system. I'm still using mine, one of which carries a part of homebrew quagi.
Beware, this dish and its associated mount is not suitable for much more than a gentle wind. I've made a wide enough support such that it doesn't tip over easily, but the dish itself then takes the beating.
My current setup
|The single band patches are easier to make. I use a 2.4 GHZ W0LMD patch with a covered 'BBQ' dish and a pair of locally-designed circularly polarized 436 MHz quagi to work AO-40 QRP at decent squint. One of these quagi will make the trip by itself with more power. I should do write-ups of these up as well someday.||
Telemetry I'm currently studying the AO-40 telemetry archives. I have software to display this information via a web browser, but it's still barely 'alpha' quality.
Here's a kind of a telemetry history of AO-40, which is large file (340K) containing the text sent by AO-40, whenever that text changed in a meaningful manner. You can, from that, see what the ALON/ALAT was at a given point in time, run predictions using the KEPS for that orbit in the archive, and determine things like what the squint was probably like at a give time. Further study will identify periods when the sun angle was bad, etc. One of these days, i'll break it up into years so it is'nt quite as huge.
I'm currently using this to compare a model of what the Project EAGLE Sun/Earth sensors might do against actual data from AO-40.