Post by 321 treeclimber on Jun 25, 2019 7:31:05 GMT -5
I was given a beam antenna and so starts the restoration and installation of a well kept and intact moonraker 4. Taken down in the late 70s, I'm told, then wrapped up and stored in an attic til now. I've decided to put it on a rohn 40'ft tower so i went ahead and just this weekend poured a concrete base for this tower, which i got in trade of some tree work last year. The base was simple, cut the ends out of a 55 gallon drum, dig a hole so the edge of the drum sticks up out of the ground about 4 inches. drop in a 4 inch layer of # 2 stone and fill with concrete. Level top. Done. Simple yes...easy,NO. Thats another story. Any way thats where its at. Next phase is antenna resto. 321
Is it a freestanding tower, or is it guyed? For example, a 40' Rohn 25G self supported tower requires a concrete base size of 6' x 6' x 4'. The guyed version is 3' x 3' x 4' (I believe). A typical 55 gallon drum is 1.9' in diameter and 2.79' in height. So it's no where near the specification Rohn calls for.
if it were me, and I was putting up a Moonraker 4, I'd use what Rohn calls out for, especially if you get ice and/or wind in your area. Also, I'd use a fairly good rotator as the Moonraker has a large wind load area.
Post by 321 treeclimber on Jun 27, 2019 8:23:24 GMT -5
10-4 CB, THIS WILL BE GUYED. i also poured a 6"inch by 6'ft. Square pad around it. Made a nice service area for future maintenance. Haven't looked at rotors yet, any particular brand or type i should look at ? 321
I got this from Jay in the Mojave a while ago, just thought I'd post it for a heads up on that reflector wire idea.
The Moonraker 4 is a great beam antenna. It was designed around inexpensive parts, but was very well designed and operated very well. Having good gain and great rejection.
There are mods out there that install more reflector wires on the quad reflector. But this will only degrade the Moonraker 4 performance big time. This being proven with many experiences, and seeing the beams pattern be distorted from Eznec, an antenna molding program.
The best thing that you can do is use good coax like the LMR-400 and install the Moonraker 4 on a tower, getting the antenna as high as possible, with a good rotor, like a HY-Gain 4 or Tailtwister Rotor.
Post by 321 treeclimber on Jul 17, 2019 14:40:30 GMT -5
Roger that cb. Im sure I'll have at least a few questions. Im going to continue tower resto for now and along the way order the coax, rotator and control and all the cable and hardware. Figure I'll be assembling the beam by mid September.
I turned mine with a CDE-44, a ham friend who had a TV shop ordered for me along with the beam. At the time, he claimed it would be able to turn stacked Moonracker IV's. I never had any problem, and still use this same rotor today. It is however rated in the original literature for only 2 sq ft. I would not want to try stacked beams, but I also think 2 sq ft is under rated. Hy-gain bought out CDE, and IMO the CD-45II is a close second. It is rated for 8.5 sq ft wind load. If buying a new rotator for that antenna, the 45II would be what I would go with.