#76 - DX Commander Assembly
In Ep 74 I mentioned the new DX Commander antenna that I purchased from England. Well, I finally got a chance to start putting it all together. Last week I cut the radiating element wires for the 40, 30, 20, 17, 12, and 10 meter bands and all of the ground radial wire sets, but I could not locate my wire strippers and crimpers to complete them to I had to put the build on hold.
One thing that I would like to mention. In the instructions it mentions that there is an option to adding the 80meter band onto the antenna by having that element take the place of the 30meter element on the antenna. It gives you the length that you need to cut the element wire to create the 80meter element and how to attach it to the antenna mast.
I chose not to build the optional 80meter element at this time which turned out to be a good thing. If you cut the included wire for the 80meter element, you will not have enough wire left over for the remaining elements and radials. If you want to add the optional 80meter capabilities to the DX Commander, you will have to order 200 meters of wire when placing your order for the DX Commander.
This is something that was never mentioned when ordering the antenna, or mentioned in the instructions to build it. Now I have to place a second order with additional shipping from England just for the additional wire needed to complete the antenna build. So, that means putting off the addition of the 80meter element until a later date.
Last night I was finally able to get all the ends crimped and soldered onto the elements and radials. Today I started putting everything together to build the antenna so that I could test it out once the storm passed and the rain stopped, but I ran into a problem.
The plate which the elements attach to does not fit onto the mast. The element plate is suppose to slide over the top all the way down the pole to the bottom and sit ontop of the plastic mounded piece at the bottom of the mast. Only problem is the hole in the center of the plate is smaller than the diameter of the mast that it goes on.
As you can see in the photo below, the driven element plate and the ground radial plate are about two feet away from each other.
For the antenna to work the element plate has to be sitting right above the radial plate with about a one inch clearance between the two. There is a wire with a spade connecter attached to it at the bottom of the photo that is supposed to connect to the driven element plate. Somehow I don't think it is going to reach.
The only way this antenna is going together using that element plate is to use a hammer and pound on the plate until it falls into position where it is supposed to be. Something I am not willing to try with a fiberglass antenna mast.
This antenna is supposed to be portable. Just slide everything together and have it in the air ready to transmit in less than 30 minutes, but the only way that works is if the parts are machined to the correct sizes in the first place allowing everything to slide together. The DX Commander missed the mark on that one.
I have written to Callum (M0MCX), the designer of the DX Commander to let him know of the manufacturing flaw. Now I have to just wait and see what happens next. The only thing I know for sure is it will now be at least another week before I get to test out the DX Commander and see how it operates. First I have to wait on another part to be shipped from overseas.
Until next time,
73
UPDATE: NOV 2, 2018
Instead of waiting for a replacement part to be shipped from England I bought a set of half-round files and filed the center hole of the element plate myself so that it would fit the fiberglass mast correctly right above the radial plate.
I hate having to fix manufacturing defects on products that I purchase, but it only cost me $15 for the file set and took about an hour to file out the plate to the correct diameter, so it was better than waiting a week for a replacement part in the mail.
Now when I get some free time again I can hopefully complete this build and begin testing the new antenna out.
Until Next Time
Aloha & 73 from Hawaii
