Quoting Jonny 290 [email protected]:
Lying in bed last night, I realized my solution to the 'noisy rotator' issue that's stopping me from putting up yagis.
Ground mounted rotator!
Pound a 1.25" steel pipe in the ground, bolt the rotator to that at knee level, run the mast up.
Here's my thinking - 15 feet of PVC with a short yagi on top, mounted at 30 degrees elevation, give or take. At the 10 foot 'eave' level, I create some sort of crude bearing using PVC that allows the pipe to spin, but not wobble. Bolt that to the eaves and use it as the anchor point up top. The pipe could down to just above ground level, where it's connected to the rotator output.
I'm in a valley so winds never get higher than 40 mph gusts, and the PVC should have plenty of 'give' to not mess up during a wind gust. I've got stuff right nowon a 12 foot PVC mast that isn't even cemented together, and it's tough.
This would allow me a steerable antenna without bothering my roommate. The rotator noise should be almost inaudible when it's mounted down so low (there won't be a window in the path to easily conduct noise) and if it's still an issue, it'd only take an hour to build an MDF box with a hole in the top to cover, insulate and protect the rotator.
Think it'll work? :D
Matt:
Sounds like a good idea. I was going to write to say that I have a similar set-up, with a Orbit 360 TV-type rotor only about 5 feet outside the window of the room I use as a shack. When it rotates, it is quite audible, and if I were trying to do work here I would find it distracting. If you undertake the above contraption, I would recommend putting the bushing on the side of the house first, before pounding the pipe in the ground :-)
A gain antenna really does make for a more forgiving setup. Be careful not to make the beams too long: you'll lose the high elevation and you'll go crazy tweaking your rotor. My 8 element 70cm does nicely with fixed elevation. I also recommend foregoing circular polarization in these antennas. See my discussion at: http://www.amsat.org/amsat/archive/amsat-bb/10day/msg56267.html (I can't seem to find a permanent link for archived messages.)
You were thinking of buying a downconverter for your HF rig. One further option for exploring satellite communications is the FT-817. These can be found second-hand quite cheaply on Ebay and other sources. I used a pair of them for some time on LEOs, and though a bit low on power, they allow you to walk outside and test your antennas in a handheld, short cable arrangement.
And for a satellite you might be able to work right now, check out AO-7 in mode A, every other day right now. (Consult http://www.planetemily.com/ao7/ao7log.php to see what mode is up today.) My 10m vertical fed by 30m of RG-8x can hear its telemetry, CW and some SSB. A loop around my shack might do even better. Last year, my HF antenna was a horizontal long wire, and I never did hear AO-7 because of the fragmented azimuthal pattern on 10m.
Since you seem to be interested in doing things yourself, you really would enjoy the Davidoff book I recommended earlier, not to mention the AMSAT Journal, whose quality is remarkably high and which is a perk of membership in AMSAT-NA.
73, Bruce VE9QRP