Antenna mast

[WRMN374]

I called DX engineering about a Universal tower kit. It's made of Aluminum. The only thing they had in stock was a Universal 4-40. The first number being for my area, and the last for the height of tower. Plus, they are supposedly self supporting. Has anyone used or is familiar with the Universal tower?

[marcspaz]

I don't have experience with the 4-40 specifically, but I have owned a couple free-standing towers over the years. 

 

What are your questions? I may have an answer. 

[WROZ250]

34 minutes ago, WRMN374 said:

I called DX engineering about a Universal tower kit. It's made of Aluminum. The only thing they had in stock was a Universal 4-40. The first number being for my area, and the last for the height of tower. Plus, they are supposedly self supporting. Has anyone used or is familiar with the Universal tower?

You might want to look at the physical requirements for a self supporting tower, specifically the concrete base/foundation and your city ordinances.  I found the price of concrete required to make a proper base exceeded the cost of the tower itself by a factor of 4, more if your municipal ordinances requires a contractor do the work as a condition of acceptance.

Just an FYI, do your homework before plunking down your money on something the vendor will not take back. 

[WRMN374]

On 4/27/2022 at 9:36 PM, marcspaz said:

I don't have experience with the 4-40 specifically, but I have owned a couple free-standing towers over the years. 

 

What are your questions? I may have an answer. 

Do I need a rotor mount? I spoke to a HAM friend today, and he said no. Decided on a DB-404B with OMNI antenna type. Horizontal beamwidth is 360. Vertical beamwidth is 27. My friend suggested to place tower close to home ground lug. Which puts it 20' from 40' tall pines. With a 40' tower and a 10' mast, and a 5' antenna puts me just above tree level. I'm on top of a hill to the north and west. I guess I'm concerned with the strength of a free standing tower, and how much loss from putting near trees.

[marcspaz]

1 hour ago, WRMN374 said:

Do I need a rotor mount? I spoke to a HAM friend today, and he said no. Decided on a DB-404B with OMNI antenna type.

 

The DB-404B is an omni-directional antenna, so there is no need to rotate it.  Just put it on the mast.  You only need to be able to rotate an antenna that is directional.

  

1 hour ago, WRMN374 said:

My friend suggested to place tower close to home ground lug. Which puts it 20' from 40' tall pines. With a 40' tower and a 10' mast, and a 5' antenna puts me just above tree level. I'm on top of a hill to the north and west. I guess I'm concerned with the strength of a free standing tower, and how much loss from putting near trees.

 

Freestanding towers are fine as long as you adhere to load and wind restrictions.  Some tower manufactures have dual ratings, too; one rating if the tower is left freestanding and a second rating if it is guyed.  If you are concerned, you should be able to contact Universal and see if they have any recommendations, if you think you are going to be on the fringe of the load or wind ratings.

 

Based on the description about the tree height vs the antenna height, you should not have any interference from the trees. 

[WRMN374]

17 hours ago, marcspaz said:

 

The DB-404B is an omni-directional antenna, so there is no need to rotate it.  Just put it on the mast.  You only need to be able to rotate an antenna that is directional.

  

 

Freestanding towers are fine as long as you adhere to load and wind restrictions.  Some tower manufactures have dual ratings, too; one rating if the tower is left freestanding and a second rating if it is guyed.  If you are concerned, you should be able to contact Universal and see if they have any recommendations, if you think you are going to be on the fringe of the load or wind ratings.

 

Based on the description about the tree height vs the antenna height, you should not have any interference from the trees. 

The person at Universal said he estimated 40' tower with DB-404B would have 1sq. ft. wind area. I mentioned the ice storm, and he stated their towers have held with 1/2" of ice. He also said if I wanted to add additional items down the road to plan ahead, and get a higher load rated tower. I feel better now. Thanks marcspaz.

[marcspaz]

@WRMN374 glad to hear it! Always happy to help!

I wish you the best and looking forward to seeing/reading about the install.