Attic Antennas - Page 2

n1das · #21 (**permalink**) 01-18-2013, 11:25 AM

Quote:

Originally Posted by perrybucsdad

Anyhow, this has me starting to think about an antenna on the house. I have a homeowners association that we belong to, and nothing in there states that I can't have an antenna, but I know my XYL has indicated that she does not want one on the outside of the house (or in the yard) and I just don't feel like dealing with any issues that it may create. I have a fairly large attic space that can be used I have this nice PVC pipe that runs from the attic all the way down into the basement for any wires that may need to go between the two. This is perfect as I plan to have my shack down there.

Here's an excellent resource to have when it comes time to put up an outside antenna or tower w/antennas.
Antenna Zoning for the Radio Amateur

I highly recommend Fred's book. Don't let the HOA push you around.

Good luck.

LtDoc · #22 (**permalink**) 01-18-2013, 11:57 AM

Consider your leg as being pulled.

Can that tripod work as a counterpoise? Yes. Or at least as part of one depending on frequency and the size of the tripod. If it's not 'large' enough just add a 'tail' off of the legs, electrically 'extending' them.
- 'Doc

n9mxq · #23 (**permalink**) 01-18-2013, 2:48 PM

With the 270 or the one you have in your photo a counterpoise isn't needed. The radials (horizontal on the 270, angled down in your picture) act as the counterpoise, or groundplane if you like.

With those antennas, the tripod and mast are only support structures..

And yes, the bucket-o-dirt is a jest..(but yes, I've seen it done)

perrybucsdad · #24 (**permalink**) 01-18-2013, 3:53 PM

Thanks all... the picture I showed I guess I should have explained at what I was asking. With the radials shooting out (same length as the antenna and sized for the correct wavelength) they act as the counterpoise.

So, is it better to have the counterpoise the EXACT same length as the antenna, or can it be longer (just not shorter)? I was listening to some guy on the radio yesterday talking about making sure it was exactly the same size, but I thought I may have read in the ARRL Handbook that it could be longer (but now I can't seem to find that darn reference). Any expert knowledge would be appreciated.

Sorry for all the questions, I just want to make sure I understand this as well as I can.

perrybucsdad · #25 (**permalink**) 01-18-2013, 3:58 PM

Quote:

Originally Posted by n1das

Here's an excellent resource to have when it comes time to put up an outside antenna or tower w/antennas.
Antenna Zoning for the Radio Amateur

I highly recommend Fred's book. Don't let the HOA push you around.

Good luck.

Thanks.... I'm not letting the HOA push me around. I know if I want to I can get one up, but a) I want to be a good neighbor, b) the XYL doesn't want one in the yard, and c) I really don't want to see one either if I can avoid it. I may look into some stealth type antenna's. I was thinking my wood burning fireplace has a nice chimney that would hide the antenna from the street side of the house, and that may be an option for a nice dipole. Could that go right up against the siding though? The nice thing about that is the antenna wire would run right down to the basement window which would be perfect.

LtDoc · #26 (**permalink**) 01-18-2013, 4:04 PM

The length of the counterpoise/groundplane does have an affect on the antenna. Basically means you may have to retune it if lengths change. In general, meaning that there are exceptions, it's 'better'/easier to deal with if the counterpoises are too long rather than too short. I've found that there isn't much 'exactness' to that, there's a bit of 'skootch' in it ('skootch' is one of those secret technical words, usually accounts for something not being exactly 'right).
- 'Doc

perrybucsdad · #27 (**permalink**) 01-18-2013, 8:23 PM

Thanks Doc... I'm a programmer by trade, so I don't deal with "skootch" too often, but that helps me understand that I have a little fudge factor if need be I guess. I guess I would rather just make it the right length so it doesn't affect the tuning.

LtDoc · #28 (**permalink**) 01-19-2013, 12:20 AM

'Skootch' and 'fudge factor' are basically the same thing. 'Skootch' is a little more safe to use in 'mixed' company. Never say 'fudge' around a female, it's got chocolate in it...
- 'Doc

(Once upon a time, in a galaxy far away, I did programming in machine language, base 2. Enough of that and really get... odd/tired of it. Weren't no 'C' or 'HTML', CBM basic was a really hi-tech sort'a thingy, not to mention punch cards. I hate computers now, couldn't care less about how them @#$ things work inside.)

rapidcharger · #29 (**permalink**) 01-19-2013, 8:17 AM

Most of the vhf/uhf base antennas are pretty low profile and not visible from the front of the house but for what its worth, I have a base antenna mounted outdoors and a couple in the attic. The attic antennas are actually higher up than the 35' mast outside so believe it or not, they regularly outperform the outdoor base antenna. And as an added plus, with attics, the coax and antenna is inside away from the elements so it lasts longer.

Having an attic antenna is nothing to be ashamed of and it's not kowtowing to the HOA. I'm the president of my HOA and can get away with murder and I still prefer attic antennas. For HF work, I might have a different opinion but for local bands, I'm doing just fine with attic antennas.

OK2BCK · #30 (**permalink**) 01-25-2013, 1:28 AM

I'd like to ask something here..
I'm planning to brew a loop antenna for 20m that would actually fit in my attic. The problem is that the roof is made out of metal sheets. Should I even considering climbing up there with the loop or backyard tripod would be better idea? I'm somehow up the hill but because I'm renting this place, no antenna can be installed on roof.

OK2BCK · #31 (**permalink**) 01-25-2013, 1:37 AM

Quote:

Originally Posted by OK2BCK

I'd like to ask something here..
I'm planning to brew a loop antenna for 20m that would actually fit in my attic. The problem is that the roof is made out of metal sheets. Should I even considering climbing up there with the loop or backyard tripod would be better idea? I'm somehow up the hill but because I'm renting this place, no antenna can be installed on roof.

maybe I should go and wash my mouth for asking such stupid question?

LtDoc · #32 (**permalink**) 01-25-2013, 4:18 AM

Washing you mouth out is a reasonable suggestion/idea -IF- you use a good brand of brandy or scotch! Otherwise, I don't think I'd go to the trouble.
Would an antenna under a metal roof work? Probably, but not very well at all. I think you would have better results placing it in the yard. As high as possible of course! (Substituting 'practical' for 'possible' is how it usually works.)
Another suggestion is to place an antenna on a window's glass. Remember the old burglar alarm foil tape? If the window is large enough, and there's no metal screens on the window, that will 'work' too. Of course there will be 'draw-backs' to it.
Good luck!
- 'Doc

zz0468 · #33 (**permalink**) 01-26-2013, 11:45 AM

To the OP, I've had excellent results using attic antennas. What I've done is make wire groundplanes using chassis mount SO-239's. Put an eye loop on the tip of the vertical radiator and dangle them by a string attached to the highest point inside the attic that you can. It was cheap, easy, stealthy, and worked just fine.

zz0468 · #34 (**permalink**) 01-26-2013, 11:46 AM

Quote:

Originally Posted by OK2BCK

I'd like to ask something here..
I'm planning to brew a loop antenna for 20m that would actually fit in my attic. The problem is that the roof is made out of metal sheets...

Go for the backyard tripod. The metal roof will detune the loop. It will also become part of the antenna, and your results will be random and unpredictable. If you have any sort of alternatives, try those first.

DarkStarPDX · #35 (**permalink**) 02-12-2013, 5:37 PM

Just wanted to add that I picked up the ARRL book Antennas for Small Spaces (Arrl's Small Antennas for Small Spaces: American Radio Relay League: 9780872598393: Amazon.com: Books) and it has LOTS of ideas for small indoor antennas and antennas that run through an attic.

Probably the best tool when experimenting with attic antennas will be a good antenna analyzer. I just picked up the RigExpert AA-54 and don't know how I ever lived without it! :-)

JeramyJ · #36 (**permalink**) 02-26-2013, 4:05 PM

Nice book there!

Fuzy_GSXR1000 · #37 (**permalink**) 02-26-2013, 8:57 PM

Quote:

Originally Posted by perrybucsdad

I just purchased and installed a new Diamond NR770HBNMO antenna and K412SNMO hatch back mount yesterday and I am so pleased with the reception that I am getting. I will have to wait until I get my ticket to see how well my VX6R does with the local repeaters, but at only 5 watts, I know I may be disappointed. We will see.

Anyhow, this has me starting to think about an antenna on the house. I have a homeowners association that we belong to, and nothing in there states that I can't have an antenna, but I know my XYL has indicated that she does not want one on the outside of the house (or in the yard) and I just don't feel like dealing with any issues that it may create. I have a fairly large attic space that can be used I have this nice PVC pipe that runs from the attic all the way down into the basement for any wires that may need to go between the two. This is perfect as I plan to have my shack down there.

Anyhow... what should I be looking at for an attic antenna? I primarily will be working the 2 meter & 70cm bands, but am also looking at a quad band transceiver that will allow me to do the 6meter and 10 meter bands as well.
recieve
Thanks for your help...

John

Perry my friend uses this from his condo balcony! http://newsuperantenna.com/