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My first 3 QSO's on AO-40

Since I own an FT-100 with 20W on 435MHz, I only needed an uplink antenna. I looked again at the cardboard box antenna's that had gotten me started in the first place. Instead, I decided to build the simple WA5VJB yagi described here, mostly because I still  had some extra 10 AWG wire laying around and a few pieces of 1/2x3/4" wooden stick. I used gel superglue to hold the wire in the pre-drilled holes in the stick.

I made the 11 element version, since I had enough wood and wire, and I figured I needed all the gain I could get. I finished it, and could not get a decent SWR with the coax soldered directly to the wire of the radiating element. The match was great at 431MHz, but stayed terrible at 435. So I went to my favorite hardware store, and bought a little bag with two copper terminal lugs. I broke off the lip, and soldered the coax right into these. Then ran the driven element trough them, and this gave me a flexible feed point. I now was easily able to adjust the SWR at 435MHz to about 1.4:1. See the pictures below. Good enough! And I only send $2 on this antenna!

I added another pvc T to the end of my $3 elevation control and used Velcro to attach the wooden boom to it. This makes it trivial to line it up with the dish. Once lined up, both antenna's move in sync. See the pictures above.

the complete setup!

After setting up, I tuned into the MB pretty easily, after the downlink-only experience the previous Sunday. I could not find my own downlink, until I swapped the uplink antenna from horizontal to vertical polarization (probably something to do with the fact that it was mounted about 10 inched from the downlink grid dish). My downlink signal was pretty weak, barely 1 s-point above my noise floor, but it was quite a thrill to hear that for the first time!  I made CW contacts with JS1XGS, JK1NYE and NN6T.
 


My very minimal setup consisted of the following:

Downlink:
    2x3' grid dish with original MMDS dipole feed
    K5GNA downconvertor with 0.95 NF
    old FT-290R, 2m multi-mode (my first radio ever!)

Uplink:
    FT-100, about CW 20W output on 435.5MHz
    homebrew 11 ele. WA5VJB beam
    25ft of RG8X to feed antenna, giving an estimated uplink 200W linear polarization

I was able to hear my own weak downlink until about MA104, at 9degrees elevation, with ao-40 at about 62000 km (over 38000 miles) from my QTH. Quite an impressive receiver on that bird!
 

 

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