Sunday, December 11, 2016

Military Masts Part 4, Antenna Masts, Guy Anchors

These are portable masts that I have used.  Not all I have deployed are posted.  There are no AB-155/U masts. 
Here's a photo of about the maximum height one person can raise alone and do it safely. Mast is about 25 feet tall and uses 6 sections plus the stand. This mast should be stabilized with at least 3 guy ropes at the top section. However when it is not windy this mast is quite stable. It is used in this configuration for a VHF antenna. The antenna is not mounted in this photo. I anchor the base with tent stakes or sand bags.

For a dipole or G5RV using this mast (2 required) the mast needs to be guyed 3 sections from the bottom and at the top with at least 3 guys properly installed.

Fiberglass mast mounted on a speaker tripod (could just as well be an antenna tripod) secured with tent stakes where 
the braces contact the ground. 6 sections for approx. 30 feet, and there is sufficient clearance for the coax to pass through the center of the mast.

Here's my easily deployed VHF mast with a 2M ground plane on the top. The height is about 18 ft. At most this set up could be about 20 ft depending on how much of the blue is placed inside the speaker stand. The mast is a $14, 12 ft aluminum swimming pool cleaning pole from Lowe's. The speaker stand is extended to gain about 4 ft. of height. Again this set up quite stable, but I secured the base with tent stakes. On a hard surface I use weight and spread the base legs further.  Guying is used if it is too windy. The home brew ground plane has been replaced with a Hustler CGT-144 and the ground plane is installed in the attic for a back-up antenna.
The unassembled CGT-144 fits nicely inside of the blue pole. Ends are secured with gaffer's tape. The CGT-144 hardware was modified to use stainless steel thumb screws and thumb nuts. There is enough space to run RG-213 or other coax through the center of the mast. The bottom of the speaker stand vertical tube was modified to allow large diameter coax to fit between the pole and ground.
This mast and my VHF go-kit can be easily transported in the car or SUV. It's not difficult should it need carried to its location of use either.
I have had several inquiries as to my method of keeping the blue pole from sliding all the way through the speaker stand. I used a PVC reducing bushing from Lowe's I took the pole to the plumbing section and bought the one that fit.
I hope to add more on masts before Field Day including the use of Jackite poles, knots and whatever else I can add.
Here is a photo of the item number of a 16 foot long multi-purpose aluminum pole from Home Depot. It costs about $30.00. It is longer when collapsed than the blue pole from Lowe's and the height gained is only 2 feet. I included the model number for those who may want a pole and have a Home Depot store and no Lowe's store.
This pole may be used as a reserve pole for an Evans Engineering portable ground plane VHF/UHF antenna. The small diameter of this pole makes storing an antenna inside of it difficult. A roll-up J-pole or some other home brew antenna may work on top of this pole inside of a piece of PVC pipe. I was going to use this pole for deploying a C-pole for 20 meters, but I never built the C-pole.
A note or two about this pole. First a PL-259 fits nicely inside the top section. This makes this pole my candidate for using the EE-3 antenna from Evans Engineering. A note on mast mounting the EE-3: In some correspondence with Bob over the past year he recommends not mounting the antenna directly on top of a metal mast, but stand it off by about a foot or more to reduce SWR. I have not made any measurements to test this. I'm guessing he has.
This page was originally done about 2010. Since then Evans Engineering is out of business and the EE-3 antenna is not available.
The second thing about this pole is it comes with a removable plastic top piece for attaching brushes, squeegees and other items. It is possible this part could be adapted for quickly attaching an antenna.
Guy Anchors: I use several kinds of anchors for various masts. Army surplus 12 inch long aluminum seem very popular and affordable. I have deployed several masts in the sandy soil of FL using these with out problems. I use some Army surplus 12 inch long steel stakes, some 18 inch long steel stakes, some that are a bit heavier 12 inch with cables attached that were made for one of the army's antennas, and some home made ones. My favorite and easily installed and removed while being super at staying in the ground are the 15 inch twist in from Harbor Freight, 99693, Auger Anchor Tie Down. These can usually be purchased for under $10.00 on sale and they come 6 per box. I paint tops fluorescent orange or place orange rings around them or I use the small orange boundary cones at the anc