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Realized my original design was really over the top and unnecessary. Really you can pick up CTV-13 with a coat hanger so I ditched my VHF antenna. In addition I omitted the unnecessary second rotor. I also shortened the top mast and put my strongest pipe in place of the previous long lightweight one. On the top mast I put two good antennas, the CYD-1430 at 46 ft, and the Winegard HD8800 at 43 ft. I then face mounted my regular day in day out use antenna (the DB8e) on the tower at about 37ft. One bay is aimed at Watertown, one bay at Plattsburg. This is about a 60 degree beam width. That antenna should not work as well as it does. Finally for fun, I put a four bay clone at 39ft. aimed between Montreal and Plattsburgh. Before raising, I tested all antennas and preamps. Interestingly even while lying on the ground it received most local stations.
Face mounting the DB8e on the DMX is very very easy and looks way cool. Note the DMX is a 40' tower on a one foot hinge addition and a 7ft mast (5'8"above tower peak). First night I am getting ABC and all the Watertown stations but it looks like a unusually good reception night. I will have to wait for some long term results. In the pictures you can see my old chimney mast still up. Summary 46ft - CYD-1430 on a RCA TVPRAMP1R preamp pointed towards Watertown (on rotor) 43ft - Winegard HD8800 on a Kitztech KT-200 preamp pointed towards Watertown (on rotor) 39ft - 4 Bay Clone on a CPA-19 preamp pointed towards Mount Mansfield Vermont 37ft - DB8e on a Channel Master 7777 (dual input one) pointed towards Watertown and Plattsburg. Configured the tower. Started winching it up and hit some leaves. Trimed the leaves and winched it up and hit some more. After triming again this time with my 36 foot ladder, I started it up again. Got up about 60 degrees hit some branches that were not going away. Was very late, so I lowered it down, and realized I needed some design changes!
I started the running the cable needed for my tower project. It is a bit OTT but I am running 8 cables up my tower. 4 coax, 2 ethernet and 2 rotor cables (one a cat5). I used a 1" conduit. Note to self, use a 1.5" conduit next time. All RG6 quad coax and only cat5 for the ethernet.
I put a cross side support in for a second rotor. For now it will hold a small VHF - basically only for channel 13. Used 2 u-bolt clamps to hold the side arm. The side arm was leftover metal from my last home made antenna project. I drilled holes every foot if I ever wanted to move the rotor over for a bigger yagi style antenna. I also manually set both rotors to the true north position. I replaced the standard TMCA with a thrust bearing mount (BBMB). This will help the main rotor which will have an 8 bay (HD8800) and 2 small-ish UHF arrow style antennas. I used a lighter and taller mast than I normally would because of the three antennas. The thrust ball bearing will help longentivity. I may face mount my DB8e, on the tower, near the rotor, for my day-in day-out reception. Today I tested out my winch setup. First trip down was bumpy due to the uneven layering of the cable in the new winch, but it went well. When I got near the bottom I realized I needed to cut out a little in front of the legs (see picture). So I wound it back up, cut out the wood ties and wound it down again. I am very happy with it. It is smooth and seems secure. Just takes more winding than I expected. V2 may be electric!
I added another 8 ft section to get it to 32ft. Next I will add the top 8ft section, take my time to set up the mast, antennas and preamps; and then wind her up,
Originally I was going to do some fancy attic attachment system and then instead decided to simply attach to the strongest point on the wall. I attached the bolt through the top plate of the first floor of the house. First I removed some drywall in my living room and drilled a 3/4" hole through the wall. Hit some nails and had issues with 3/4" bits but ultimately I got the hole drilled in 33 degree weather. Good thing I didn't do the attic solution! Had to buy a 1/2" breaker bar but boy is that bolt on tight! Seemed to work out well. I attached the winch to the post behind the tower at a nice level for turning. I then attached the winch wire on the tower at a level slightly higher than the pivot point. Yes I have lots of ladders. In the pictures, what looks like rust is actually dirt and leaf bits. I temporarily patched up the living room wall. The room needed a paint job anyway. Tomorrow I may test the winching system.
Usually with a DMX self supporting tower, you need plenty of concrete. Usually a block of at least 3' x 3' x 3' is required. However in my case I am mounting my "hybrid" tower both bracketed to my house and spiked with a base hinge (described in previous post). I decided to lock in my spikes from any shifting or torsional forces with a base cap, a slab 3' x 3' x 4". This required 6 bags of 30kg cement. After the obligatory kids hand prints and a couple of hours of sweat, considered it "locked" in. Notice the plumb bob still smack in the middle. It is strung down the middle of the 3 upright sections. The wooden post at the back is for mounting the winch, my next part of the project.
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AuthorInteresting Antenna things we're up to. Archives
December 2017
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