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Looking to get a base antenna.

Jhernan488

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What would you guys recommend for a UHF/VHF dual band base antenna?

What type of mount would I need?
I’d like to screw it into the eave on the house.

What type of coax cable would I need?

Thanks! :)
 

jaspence

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Depending on the material of the eaves and the size of the antenna, that may not work if you have any strong winds in your area. Aluminum eaves tend to be rather thin and will flex. That would put your antenna below the peak of the roof in most cases and reduce your coverage on the side where the roof peak is. If the repeaters are not too far away, this will not be a problem. The type of coax will depend on the length of the run into the radio.
 

popnokick

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Eave mounts are more properly called "gable end mounts" and are used at the peak of the roof at any side of the building where there is a peak. Most buildings have wooden construction that is capable of holding the lag screws that are normally used to hold the gable end mount. However, wind loading may be a concern depending on the size of the antenna and length of the mast on the eave mount. I never go beyond 15 feet above the roofline.... some say no more than 10 feet. Appropriate antennas would be such as the Diamond X50, X30, or V2000 or equivalents. The mast would not require additional guys to the eave, although you could install them if you wished. Google Images for eave mount antenna to see what they look like... many persons I've met don't understand what an eave / gable end mount is until they see a picture such as found in the multiple images on Google. Here is also a link with a typical price for a gable mount -
 

rapidcharger

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Rather than mount to the house, I would suggest mounting your antenna to a mast or tower out away from the house. There a number of reasons with interference from household RFI sources and lightning and fire safety being the primary reasons. Plus it's your roof. That's kinda important.
 

popnokick

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Another important point about a gable end / eave mount: they DO NOT require a roof penetration. As for lightning protection, follow NEC guidelines for grounding with a proper conductor run straight as possible down from the mount to the grounding rod.
 

prcguy

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A satellite dish "J" mount like DirecTV uses works great for modest size antennas. You can mount the foot on the roof overhang so screws do not penetrate the roof over a room, although I've never had one of those leak. These J mounts will easily handle an antenna the size of a Comet GP-6 and the last J mount I used was for a 17' 10" long Comet GP-9. That one recently had 70mph winds go by with no problems.

Another important point about a gable end / eave mount: they DO NOT require a roof penetration. As for lightning protection, follow NEC guidelines for grounding with a proper conductor run straight as possible down from the mount to the grounding rod.
 

majoco

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This has survived some pretty good blasts over four years.....but probably your house construction is different to mine....

Slim Jim sml.jpg
 

TailGator911

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BASE STATION ANTENNAS

I use standoff mounts at the eave peak to attach a mast so that antennas are above the roof line. It is buried 18" deep and I have all coax runs about 35ft. and have minimal loss into amplified Stridsberg multi-couplers. Directional yagi is for SDS scanners monitoring my local Ohio MARCS P25 Phase 1 digital simulcast system. Diamond discone for everything else. The wire and balun is end-fed PAR for HF radios. The mast is insertion poles purchased @ Ace Hardware. The mounts are easy to install, lag bolts into wood side, very sturdy and has survived some major wind storms.

JD
kf4anc
 

n5ims

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The gable end mounts (the eave mount in the link) has one serious issue that was briefly mentioned. The mounts are generally pretty close together so the wind has quite a bit of leverage against the mounts and can easily pull them out during very high winds. If you use two (or more) wall mount brackets that are spaced at a fairly good distance apart (and have the lag bolts securely screwed into the wall's studs) you will have a much more secure mounting and your mast will handle much stronger winds. You can often found a pair of wall brackets for less money than the gable end mounts to boot.

For either type of mount, make sure that the mount will properly hold the size mast you plan on using since you want the mast securely held by the mount and if the mast is too small, it will slide down easily and if it's too large it may not fit in the mount. This is often an additional advantage to the wall mount brackets since they don't use U Bolts, but more often what I call "pinch brackets" that pinch the mast between two rounded V slots that will securely hold a wider range of mast sizes.

 

AC9BX

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I favor making my own antennas. For mobile it's difficult, getting small parts to hold well and attach to a proper mount. But at home you're open to whatever you want to do. Build a Yagi (dual band is tricky) or a Log Periodic for a beam, or try a quagi. Or one can build a simple dipole or ground plane for omnidirectional work. A vertical dipole for 2m with stubs for 70cm makes a decent dual band omni.

A word of caution when mounting the gable (the triangle on the side of the roof), driving lag screws into the house may not hold very well. It's typically just a panel of plywood. Reinforcement inside is highly recommended. Threaded rod with washer and nut on inside and outside makes it substantially more secure and if reinforced with some lumber inside much more secure.
A mast as in Tailgator's photo is how I'd go about it. This puts the downward weight on the ground. Mounts on the house now only support lateral forces, much easier on them. Rohn makes "tv" type mast, which is fine for modest antennas, in 16 gauge steel (as far as I know the one, others are 18).

Use the best coax you can afford. The last place one should skimp is feedline and it's often where hams do, $600 radio, $700 antenna, $25 unknown-hamfest coax.
Crummy RG58 (radio shack, no-name, cheap stuff that comes with the mobile mount, etc.) at 70cm, 100 feet of this stuff will lose almost 10dB. That's 50Watts from the radio will yield about 5 or 6Watts with a perfect antenna, worse if it doesn't match. You're better off standing on the roof with an HT. Times LMR400 (Belden 7810A, Jefatech LL400, others) will drop less than 3dB, about 27Watts into the antenna. Cut that in half, almost 38Watts. LMR600, a monster to work with, big expensive connectors, will drop less than 1dB over 50 feet.
It will be much better at 2m.
 

W5lz

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I agree, a good feed line is very nice to have. Just don't go over-board with it! In most cases on VHF/UHF LMR-400 will do just fine, same with HF too. Unless you have a really long run, over 150 feet or so, LMR-600 is a waste of money, sorry 'bout that. There are losses with any/all feed lines. You will never get all the power from your transmitter to the antenna unless you connect that antenna directly to the radio, and that's just not all that practical, is it. Every antenna installation is different from any other installation. Never gonna be two exactly the same, and that's not all that bad a thingy.
 
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