| Author |
Message |
    
Drexel
| | Posted on Tuesday, January 13, 2004 - 10:31 am: | 
|
Does anyone know of a 11 meter antenna that will work in the attic of our home with a metal roof? I had an A-99 mounted at a 45 degree angle in our former house with a standard wood roof and it worked quite well. We can not have any outside antennas other that dishes in our neighborhood. |
Ca346
| | Posted on Tuesday, January 13, 2004 - 12:00 pm: |
|
NOPE. Now that's a dilemma!  |
Dx431
| | Posted on Tuesday, January 13, 2004 - 12:27 pm: |
|
A dipole would work. |
Ca346
| | Posted on Tuesday, January 13, 2004 - 2:06 pm: |
|
Jason (431):
How could a Dipole possibly radiate under a full metal roof? Wouldn't you splatter all of your neighbors? |
Radiodude
| | Posted on Tuesday, January 13, 2004 - 4:24 pm: |
|
Get you a tuner and use it to load the roof up!! It should make a really good antenna!!! |
Ca346
| | Posted on Tuesday, January 13, 2004 - 6:57 pm: |
|
Your a BIG help....  |
Crafter
| | Posted on Tuesday, January 13, 2004 - 7:14 pm: |
|
Yea the roof could act as a radiator I would use a dipole. Cant hurt to try. Try the antron anyway you got it might as well give it a try. Also those Isotrons work well. I see them advertised everywhere. |
Ozzie
| | Posted on Wednesday, January 14, 2004 - 8:45 am: |
|
I used to think that an antenna under a metal roof would not work effectively - that is until I had a stand at a trade show. Despite asking for an outside booth or at least one near an external wall I was placed in the middle of a metal shed.
I'd though I'd at least rig the travelling wave antenna up so that potential buyers (read government departments) could see it. So I did with it being an average of 6" below the metal roof. During the first day I got curious and fired my IC-706 up. SWR was less than 2:1 from 1.6MHz to 31MHz. MMMmmm so I put out a few calls. Worked several contries on 20 and 40m during Friday and Saturday (at least half a dozen states), worked the State Emergency HQ in Wollongong (about 600miles ) on 2.8MHz, Royal Volunteer Rescue Base at Lake Maquarie (470miles) on 2.76Mhz. Both pof these were during the mid morning period. Sunday morning I worked my usual 80m sched with stations thate were 600, 500 and 200 miles away. 11m saw me working stations in most Australian states.
Needless to say I sold several of each model antenna and 6 IC-706s that weekend.
When it comes to antennas there is only one real rule - TRY IT AND SEE.
Oh yeah I was in a little town called Gunedah about the middle of nowhere in the state of New South Wales. |
Pig040
| | Posted on Wednesday, January 14, 2004 - 9:47 am: |
|
I talk out of my barn on my mobile all the time with a wilson 5000. Skip talk just fine. I was trying to use it as a block for three directions, but I still recieved 360 degrees. Surprised me, the roof is tin, as are the walls. |
Ca346
| | Posted on Wednesday, January 14, 2004 - 11:13 am: |
|
Ozzie:
That is totaly amazing! I'll bet the RF was bouncing around that building like a ping pong ball.... |
Dx431
| | Posted on Wednesday, January 14, 2004 - 12:50 pm: |
|
I have friend who runs a CB shop and he would tell me about all the different types of wire antennas he would build when he was a kid.
When he stayed with his grandparents he would make different kinds of wire antennas. He loaded up the metal rain gutter an talked all over with it.
Here's an idea, do you have a wooden porch or deck?
Make a dipole and run the wire underneath the hand railing and run the feedline under the porch and into the house.
Noone will ever know it's there. |
Kiwikid
| | Posted on Wednesday, January 14, 2004 - 1:18 pm: |
|
Hi Team,Drexel check to see if you are permitted a flag pole.If so insulate the base bury the coax and load it up.
Kiwi Kid |
ELCO Man
| | Posted on Wednesday, January 14, 2004 - 7:25 pm: |
|
A metal roof in close proximity to the antenna will in all probability detune the antenna and reflect much of the signal back to the ground. This reflected signal "Might" reflect upward and out but it would be at a much reduced signal strength compared to the original signal.
Check out the ARRL Antenna Manuals for designs for "Stealth Antennas".
That ELCO Man. |
Bruce
| | Posted on Wednesday, January 14, 2004 - 10:23 pm: |
|
the first MOONBOUNCE was done with a rombic.... a very long piece of wire. |
Drexel
| | Posted on Thursday, January 15, 2004 - 2:48 pm: |
|
Many thanks to you guys for the help on my antenna problem.Had to lean the antron over to 45 degrees so it would'nt hit the metal roof in the attic. It received ok ,but swr was around a three and I can't have that.We just spent a ton on landscaping, flower beds etc and the flag pole is out,but a good idea.What is a good website to get instruction on wire antennas and do you have to by a tuner? |
jpm
| | Posted on Thursday, January 15, 2004 - 9:52 pm: |
|
I knew an older fella here in florida, that loaded a metal kitchen chair, a shopping cart, and a garbage can. Anything metal will radiate a signal, just not very well. |
