Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: Vertical to chimney?  (Read 1804 times)
NEWBIE2
Member

Posts: 3




Ignore
« on: November 03, 2002, 03:25:01 AM »

Hello all.  I'm new to ham and I'm ready to take the test.  Just need to find a time that works with myself and the local volunteer.

My question involves if there are any problems putting a vertical antenna on the chimney?  Use is for 2m and 70cm and it will first be used with a handheld and hopefully later with a base.

We have a restrictive covenant that prohibits any sort of mast/tower.  I plan to run a ground wire down the side of the house.  There is a satellite dish antenna right next to the chimney as well.  The vertical will be mounted on the top side of the chimney.

Any thoughts?  BTW, what does CC&R stand for?

Thanks!
Doug
Logged
KF4ZGZ
Member

Posts: 289


WWW

Ignore
« Reply #1 on: November 04, 2002, 06:44:30 AM »

CC&R...Codes Covenants and Restrictions
Created by the minions of the devil to bedevil us well meaning hams  Wink
 No reason at all as long as you make sure you have everything secure. BUT... at vhf and uhf you need to keep the feedline as short as possible to cut down on feedline losses.
 btw- your local 'shack' store should have chimney mount kits and parts to help the project along.
73 de Matt, kf4zgz
Logged
KA2UUP
Member

Posts: 388




Ignore
« Reply #2 on: November 04, 2002, 08:16:33 AM »

I also suggest you use low loss 9913 cable.  Make a search on the net and you will find a couple of dealers that will sell finished sections for you.

The 9913 cable has the lowest loss in dB per foot for VHF and UHF.  If you have a whip with gains in the 6.0 to 8.0 dB range, you'll have a very good VHF/UHF station.

Just some advice from my experience.

73 and good luck DE Bert @ KA2UUP
Logged
WB2WIK
Member

Posts: 20666




Ignore
« Reply #3 on: November 04, 2002, 12:29:09 PM »

CC&R is actually "Covenants, Conditions and Restrictions" in common language.  Codes are normally not contained in CC&Rs, but in local ordinance (laws).  CC&Rs are not laws, but are Deed Restrictions implemented by developers and attached to the property deed when filed with the local administration office, and are enforced by Homeowner Associations, and not by police.  If CC&Rs are tested in court, it is a civil matter, just as any proceeding between individuals.

Using a chimney to support a VHF vertical is a very common application, and thousands of hams do this all the time.  The only thing I'd caution about is to make sure your particular chimney has adequate strength for the job, since chimneys are not designed to support anything -- they are designed to vent or exhaust smoke and hot air from furnaces or fireplaces.  Usually, the cement, brick or tile trim on the outside of a chimney is purely decorative and serves no other purpose than to look nice.

To "test" a chimney's strength, you could hire a professional, or you could do what I've seen the "pros" do (and now I do, myself), which is to stand in a secure position on the roof next to the chimney, brace yourself for imbalance in case the chimney should move, and lean your body weight into the chimney from the sides available to you.  If you can press 200 lbs against the chimeny and nothing budges, it's probably good enough to hold up a 20 pound vertical and its support mast!

73 de Steve, WB2WIK/6

Logged
NEWBIE2
Member

Posts: 3




Ignore
« Reply #4 on: November 07, 2002, 02:20:05 AM »

Thanks for all the informative responses.  I'm scheduled to take the exam in a few weeks.  My wife is beginning to change her mind about having an antenna on the roof.  I informed her even Congress is started to wise up and considering legislation to ensure hams have reasonable antennas.  I guess after the twin towers disaster they've realized how helpful amateur radio might be.  She's not sold yet but we'll see how it goes.  It's not like I'm painting the house pink and parking my truck in the front yard.  No offense to those with pink houses and trucks in the front yard. Smiley

Thanks,
Doug
Logged
WB2WIK
Member

Posts: 20666




Ignore
« Reply #5 on: November 07, 2002, 01:03:45 PM »

Doug, based on your last response we'd all assume your wife owns the house, and owned it before you were married.

Otherwise, I'd suggest you put up your antenna on your half of the roof.

WB2WIK/6
Logged
KA9ZIM
Member

Posts: 63




Ignore
« Reply #6 on: November 07, 2002, 06:23:21 PM »

I have a dual band (VHF/UHF) antenna and a 222 MHz antenna in my attic and both do very well.  Both would perform better mounted on the chimney or the roof, but I live in the Chicago area and I'm surrounded by repeaters.  I can be heard on any machine I can hear, and my simplex range is very good too.  Attic mounting may be something for you to consider.  Good luck on your exam!
Logged
NEWBIE2
Member

Posts: 3




Ignore
« Reply #7 on: November 07, 2002, 06:34:48 PM »

Ha!!!  Not bad.  I might use that reasoning.  Without starting a whole thread on who wears the pants, I usually find it best to discuss certain issues.  We've had a good time with the whole thing and we both know it will go up unless someone in the neighborhood tries to block it, which is not likely.  Just easier on the marriage to talk about things.  I didn't intend to make her out to be a beast.  It is more fun that way however.

Thanks,
Doug
Logged
KC0ODY
Member

Posts: 78




Ignore
« Reply #8 on: November 22, 2002, 02:06:10 PM »

KA9ZIM- what brands of VHF/UHF antennas do you have installed in your attic?

73 de Jackie KC0ODY
Logged
N6AJR
Member

Posts: 9927




Ignore
« Reply #9 on: November 30, 2002, 08:34:13 PM »

Take one end of a piece of coax and strip off the outer cover for 19 1/2 inches.. .. Next pull the center conductor through a little window you make in the braid with a pen tip. Streach these out opposite of each other. Now you have a 1/2 wave dipole for 2 meters.

 Mount it vertically with the center contuctor pointing up the shield pointing down, and run the coax away from it at a 90 degree angle ( like a T ) for at least 1/2 wave length for repeater use.  M

ount it horizontal with the feed droping straight down for ssb work.  You can tape this to a window or a stick or what ever.. it's a half wave dipole on 2 meters and works really well.. try it..

Hook the other end to your radio.  73  tom


<  19 1/2 "> <  19 1/2 ">


----------- |-------------
            |
   braid    |  center conductor
            |
            |
            |  
            |
            |

            coax to radio

******************************************
Logged
N6AJR
Member

Posts: 9927




Ignore
« Reply #10 on: November 30, 2002, 08:39:41 PM »

the pic above didn't work right... move th coax tail under the center of the dipole... thanks  tom
Logged
W4TYU
Member

Posts: 518




Ignore
« Reply #11 on: December 10, 2002, 04:50:33 PM »

Hopefully this is not too late but I saw no mention of mounting a 2 meter whip on the vent pipe. They are usually on the side of the roof away from the street and very rarely noticed. Many of the chimneys in new construction are only wooden frames enclosing a metal flue and not anything you would want to attach an antenna to.

I am using a dual band 2 Meter/440  antenna in the attic. I tossed a cord over one of the highest rafters near the peak and pulled it up to get a bit more height.

Go for it. even if you have to use a magnetic mount on a cookie sheet.  (that works also)

Ole man JEAN
Logged
KA0GKT
Member

Posts: 555




Ignore
« Reply #12 on: January 29, 2003, 05:22:49 PM »

In some localities, Chimney mounted antennas of any kind are prohibited by law.  The constant vibration of an antenna is said to weaken the mortar to brick joint and makes an otherwise sound chimney a hazard.  this usually is in local firecodes.

There is at least one company that makes an antenna disguised as a chimney vent (sewer stack vent).  It is housed in a piece of white PVC sewer pipe and you slip it over an existing vent pipe.  

Depending upon the composition of your roof, the existance of an attic (or not), you could consider placing a standard movile antenna over a sheet metal ground plane in the attic.  While this wouldn't be as high as if it were on the chimney, it would be out of sight.  I have seen small (3-4 element) yagis mounted in the crawl space of an attic, and even had a 11-element HyGain Yagi on a TV antenna rotor in a larger ranch-style house attic at one time

73!

de KA0GKT/7
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!