Discone installation

jazzboypro

Member
Joined
Aug 7, 2019
Messages
280
Location
Laval
Hello, i have a discone antenna that i want to install (Diamond D-130N). About 21 feet above the ground is pretty much the best i can do for now but it would at least be higher than my house. For the mast I'm planning on using this Fence pole each one is 7 and a half feet long and a diameter of 1 7/8 inch.

I will drive the first pole in the ground maybe in a cement bucket. The mast will then be attached to a solid structure at 45 inches about the ground and to another structure 85 inches above the ground the rest of the mast will not be attached to anything (roughly the last 14 feet of the mast) The antenna is not heavy (2.2 pounds). The winds here do not exceed 50-60 miles/h. Do you think the mast would hold up ?

Many thanks
73
VA2FCS
 

DS506

Member
Premium Subscriber
Joined
Sep 24, 2011
Messages
46
Location
Ohio
At minimum, I would do three lengths of rope/wire to the top to guy it.
 

GROL

Member
Premium Subscriber
Joined
Aug 29, 2017
Messages
178
At minimum, I would do three lengths of rope/wire to the top to guy it.
I vote for guys ropes as well. Paracord works very well for light loads. Be sure to use black for UV light resistance. Flag with a bright color if you are concerned about someone walking into it. Bright colored paracord will fade and deteriorate in the sun.
 

jazzboypro

Member
Joined
Aug 7, 2019
Messages
280
Location
Laval
I might be able to install one guy rope/wire but the second one would really be in the way. I'll try to post a picture of where the mast would be.
 

devicelab

Whacker Extraordinaire
Joined
Jul 18, 2016
Messages
954
Location
Bothell, WA
Use EMT conduit -- available at any decent hardware store and it's cheap too. Comes in various sizes @ 10ft lengths. Usually 1" works great for discones.

For my discone, I used this Amazon.com: Ambient Weather EZ-HD-PTP Heavy Duty Mast to Mast Mounting Kit: Home & Kitchen

This got me a 20ft mast relatively cheap. It made the whole assembly a little heavier than I would have wanted but it works well. I used (2) of the above for extra rigidity.
 

chief21

Member
Joined
Mar 2, 2004
Messages
1,522
Location
Summer - Western NC; Winter - Tampa Bay FL
Use EMT conduit -- available at any decent hardware store and it's cheap too. Comes in various sizes @ 10ft lengths. Usually 1" works great for discones.
EMT is considered to be "thin-wall" tubing, which is why it's easy to bend when installing conduit runs... but it doesn't make terribly strong antenna masts. A stronger alternative is using galvanized, top-rail sections. These come in 10.5 foot sections, with swaged ends that fit together like old-style TV mast sections (but much stronger). Available at most big box home stores.
 

prcguy

Member
Joined
Jun 30, 2006
Messages
11,524
Location
So Cal - Richardson, TX - Tewksbury, MA
If you use EMT in a size common for antenna masts like 1.25" to 1.5" OD then its plenty strong in 10ft sections. Fence top rail is a little better and its available in 21ft sections. Commercial top rail is not swaged.

EMT is considered to be "thin-wall" tubing, which is why it's easy to bend when installing conduit runs... but it doesn't make terribly strong antenna masts. A stronger alternative is using galvanized, top-rail sections. These come in 10.5 foot sections, with swaged ends that fit together like old-style TV mast sections (but much stronger). Available at most big box home stores.
 

consys

Member
Premium Subscriber
Joined
Jan 2, 2004
Messages
166
Location
Suisun City, CA
I used EMT as the guy wires, not the mast. Flatten the ends of EMT and you can drill a mounting hole and bend an angle as required.

I couldn't space guys at 120 degrees or 0-90-180-270. I could only go 0-90-180 at the edge of my roof 15 foot roof. The 90 leg is taking the load both directions, which cables will not do.

Where I live we have 20-30 mph wind nearly all the time with gusts over 50. Its destroyed two discones, but the mast & emt has held up very well. The mast is surplus military aluminum about 2 inch from a swap meet. It's 20 feet tall with the "guys" at ten feet.
 
Last edited:

jazzboypro

Member
Joined
Aug 7, 2019
Messages
280
Location
Laval
I'm using a 16 feet painter's pole. The first 8 feet is fiberglass and the telescoping part is an 8 feet aluminum pole. The pole is installed on my 4 feet above the ground patio. I was able to guy it properly.
 

merlin

Active Member
Joined
Jul 3, 2003
Messages
873
Location
South East Idaho
The mounting is a bit different than my discone. the top of the mast should accommodate the coaxial fitting so the mast should not be much in diameter.
Don't recall who made mine, it mounts to a 1.25" mast directly with an inner 'N' connector.
Mine is 6' above a flat roof. works quite well and also splits to my TV.
Looked at the specs for this Diamond and laugh. No wideband antenna has +gain. (bloated specs to sell antennas.)
Guying your mast is suggested even though wind loading is small.
Mine is double clamped to a vent pipe and barely sways in 50 MPH wind.
The mast is the thin wall stuff described above and never folded in 60MPH gusts.
I am re doing the coax right now,(like today/tomorrow) I'll get photos later.
 

N1FKO

Member
Joined
Jul 26, 2019
Messages
43
I once telescoped two sections of schedule-80 steel pipe together and bolted it to the side of the house. No guy wires required. :)
 

900mhz

Member
Premium Subscriber
Joined
May 13, 2005
Messages
237
Location
Hamden CT
I once telescoped two sections of schedule-80 steel pipe together and bolted it to the side of the house. No guy wires required. :)
Now that's more like it.
Nice thing about Sch 80 is you can weld brackets right to it.
 

prcguy

Member
Joined
Jun 30, 2006
Messages
11,524
Location
So Cal - Richardson, TX - Tewksbury, MA
Years ago at a repeater site we needed to get a UHF master receive antenna above existing antennas so we used sched 80 pipe. The tower was about 40ft tall and huge with three legs spaced a good 10ft apart and probably 8" in diameter designed to hold multiple large point to point microwave dishes. There was an existing huge dish antenna about 10ft diameter near the top of the tower that had a length of vertical pipe about 10ft long as part of its mount.

We got 21ft lengths of sched 80 pipe in the next two sizes down from the dish mount and winched them up through the dish mount pipe then pinned everything with about 2ft of overlap. The antenna was prepped and mounted as the smallest pipe popped out of the others right above the dish mount where we cold still reach it and still below the top of the tower. Then the 7/8 Heliax and jumper was SS strapped to the smallest pipe as it was winched up out of the other pipes. The smallest pipe was still pretty large somewhere around 4" OD.

So that would be an original 10ft pipe as part of the dish mount with about 19ft of pipe sticking out of that including overlap then another 19ft of smaller pipe including overlap then the 21ft Telewave 10dB fiberglass stick. The dish antenna was hard mounted so that would leave 38ft of pipe and about 18ft of antenna (after its mounting pipe is subtracted) for a total of about 56ft of pipe and antenna unguyed sticking up from a 40ft tower putting the antenna over 70ft in the air on a 3,000ft mountain. It was magnificent when completed and I could have stared at it all day long.


I once telescoped two sections of schedule-80 steel pipe together and bolted it to the side of the house. No guy wires required. :)
 

900mhz

Member
Premium Subscriber
Joined
May 13, 2005
Messages
237
Location
Hamden CT
Years ago at a repeater site we needed to get a UHF master receive antenna above existing antennas so we used sched 80 pipe. The tower was about 40ft tall and huge with three legs spaced a good 10ft apart and probably 8" in diameter designed to hold multiple large point to point microwave dishes. There was an existing huge dish antenna about 10ft diameter near the top of the tower that had a length of vertical pipe about 10ft long as part of its mount.

We got 21ft lengths of sched 80 pipe in the next two sizes down from the dish mount and winched them up through the dish mount pipe then pinned everything with about 2ft of overlap. The antenna was prepped and mounted as the smallest pipe popped out of the others right above the dish mount where we cold still reach it and still below the top of the tower. Then the 7/8 Heliax and jumper was SS strapped to the smallest pipe as it was winched up out of the other pipes. The smallest pipe was still pretty large somewhere around 4" OD.

So that would be an original 10ft pipe as part of the dish mount with about 19ft of pipe sticking out of that including overlap then another 19ft of smaller pipe including overlap then the 21ft Telewave 10dB fiberglass stick. The dish antenna was hard mounted so that would leave 38ft of pipe and about 18ft of antenna (after its mounting pipe is subtracted) for a total of about 56ft of pipe and antenna unguyed sticking up from a 40ft tower putting the antenna over 70ft in the air on a 3,000ft mountain. It was magnificent when completed and I could have stared at it all day long.
that 10 foot dish almost reminds me of my earlier days of an AML microwave link, with circular waveguide. Those were the days...rain fade sucked though...weekly nitrogen pressure checks
 

prcguy

Member
Joined
Jun 30, 2006
Messages
11,524
Location
So Cal - Richardson, TX - Tewksbury, MA
Funny you should mention AML. I worked in a Hughes microwave division and my lab was next to the AML lab where they made that stuff. When my ex manager of another division left Hughes and took all the AML customers with him I got to raid the empty AML lab and training room getting a huge dozen or 14 channel AML system with all transmitters, combiners, waveguide, etc, then sold it all to the guy who got all the AML customers.

that 10 foot dish almost reminds me of my earlier days of an AML microwave link, with circular waveguide. Those were the days...rain fade sucked though...weekly nitrogen pressure checks
 

900mhz

Member
Premium Subscriber
Joined
May 13, 2005
Messages
237
Location
Hamden CT
we had a 36 channel system. The fun was pushing out to 38 channels. For the most part , it worked. Every once in a while, a power supply would come and bite, and it was always the -24 VDC output crapping out.
 
Top