EME activity at W7IUV (DM43el) started in June, 1982, and lasted until October, 1991. All activity was on 144 MHz. During that time, thousands of QSO's were made with 349 different EME stations in 49 countries and all 50 states. All equipment was home-brew. The final amp was pair of 4CX250's in P-P with about 1350 watts out. I had three different antennas. The first was an array of 4x8 element Quagi's. Next was an array of 8x13 element Quagi's of my own design. Finally, I built an array of 16x8 element W1JR Yagi's. The cross boom is 30 feet of Rohn 25 tower sections. The vertical masts are 25 feet of chain link top rail. Feed lines are all CATV hardline. Operation was curtailed when the array had to be dismantled in preparation for a move to a new QTH. I never did put it up at that QTH in DM43ch.

After moving to WA, DN07dg, I got interested in WSJT, primarily for MS work. I had put up one of the original W1JR yagis on a short tower for tropo work and after about two weeks had worked all the active stations I could find within MS range. Of course the next step was EME!

tower 3

As one might expect, I went after W5UN first. Since I had in the past worked Dave on CW with one of these yagis and 160 watts from a portable location, I was reasonably sure I could do it with WSJT. My TS2000 with a160 watt brick, no preamp, and the single 8 element yagi did just fine, actually easier than I thought. WSJT QSO’s with RN6BN, KB8RQ, DL8GP, S53LM, RA3AQ, and RK3FG followed in the next few weeks. Contrary to what some people would have you believe, this was pretty hard even with WSJT! I started looking at what I could do for more antenna quickly. This is one experiment I tried with XPOL:

temp

After making QSO’s with ON4GG and ON4IQ, the thing fell over. I decided that XPOL was not worth the effort due to the complexities of the feed system required. I needed something that would survive the constant high winds I get at this QTH. I was corresponding with VE7BQH about upgrading my W1JR yagis to a more modern design and after working out a few bugs with the 50 ohm feed came up with this:

4x8

This 4x8 array of W1JR/VE7BQH yagis is the interim EME antenna and worked better than expected. At this writing I have QSO’s with AA9MY and DL8EBW, both single yagi stations. My initials from this QTH on WSJT stand at 62 most of which were made in less than two weeks! Still running the TS2000 with a preamp now and my old P-P 4CX250 amp at about 600 watts out. This is a temporary antenna and will be replaced with either 8 or all 16 yagis as soon as I can get the next tower installed.

October, 2005
The fourth tower has been installed and the 8x8 array operational for several months:


Some of the piece parts:

Center of the array. TVRO dish acutator is used for the elevation drive. Larger box left center is the preamp/relay assembly. Smaller box with blue tape is the elevation position transducer assembly. The two port half wave power divider is fabricated from common plumbing parts and three N connectors. The main boom is a piece of  2-3/8 inch diameter well pipe. The hinge is made from a piece of 3 inch well pipe withthe main boom running through it. Brackets are welded to the hinge for attachment to the main mast using U-bolts.




The yagis are fed with LMR 400 clone cable. 4 port 1/4 wave power dividers are used because that's what I had. If the material was available, I would have preferred a different solution. Rotator is a Ham-M type with a digital readout. Again, it's what I had on hand. If cost were no object there would be something different there. The yagis are the same as the ones used in the interim array above.