eHam

eHam Forums => Antennas and Towers and more => Topic started by: KD8UXE on March 15, 2013, 06:23:30 AM



Title: I live in a valley
Post by: KD8UXE on March 15, 2013, 06:23:30 AM
My problem is what kind of antenna's will I need for 2 meter to 160 meter the most I can get is about 70 feet. I am going to build my own antenna's so I can tune them my self. I need a good starting point for this if anyone can help.here is my lat and my long if it will help.

lat.(37° 26' 7'' N)

long.(81° 6' 27'' W)


                                                                                                                            Thanks,greg


Title: RE: I live in a valley
Post by: N8BOA on March 15, 2013, 07:38:41 AM
You are in a valley aren't you
Looks like a good hill to the north but maybe far enough for hf not to come into play
   2 m will be an issue
Hill to the South East
  10m-20m to the south east so so should be good for the Caribbean though   ..--..
40 -160
   Now we are getting into NVIS stuff so FL all SE state side ok  should be good for the Caribbean though
 Might as well stay away from verticals the would still talk but It is hard to beat a good O dipole
Remember all antennas are a compromise i.e. no such thing as a perfect antenna
Sean


Title: RE: I live in a valley
Post by: KD8UXE on March 15, 2013, 08:25:05 AM
Yes this is my problem I am going for my general test next month and I need to figure out the best way to get my antenna's up I am thinking 80 meters and down, but where i'm at I can get about 80 feet high.So I know I have my
work cut out for me.



                                                                                                              Thank's for all the help,Greg


Title: RE: I live in a valley
Post by: W5DXP on March 15, 2013, 09:48:42 AM
So I know I have my work cut out for me.

Most hams worry needlessly about this problem, at least for HF operation. How far is it to the mountains? How high are the mountains? Divide how high they are by how far away they are and take the arctan of that figure. That's the angle one needs to overcome and it is usually pretty small compared to the take-off-angle of most  antennas. My advice is not to worry about such, just put up your HF antenna, and see how it works.

Of course, the line-of-sight limitation for VHF and UHF is a completely different problem.


Title: RE: I live in a valley
Post by: W0FM on March 15, 2013, 11:11:53 AM
Cecil is absolutely correct.  I built a new home in a valley 15 years ago.  I knew it was in a hole, but the choice to live there was mine.  Starting at my back yard and going east the ground rises about 250 feet in a mile.  I didn't worry about it long though because I figured I had only these options for HF:

1.  Move
2.  Find another hobby
3.  Rent a bulldozer and level that hill to meet my needs (about 900 acres)
4.  Put up the best antenna I can and quit worrying.

I chose #4.  In 15 years I have 249 DX entities confirmed with a dipole in my attic.  MOST of those contacts are in Europe, the Middle East and Africa, the exact direction of that hill I dreaded.  It came down to the takeoff angle of the antenna.  The hill was almost invisible to my dipole.

So, what are your options, Greg?  Probably pretty similar to mine and lots of other hams.  Just put something up (probably not a vertical) and have fun.  You can always tinker with new ideas while you are racking up contacts.  

73,

Terry, WØFM



Title: RE: I live in a valley
Post by: N7SMI on March 15, 2013, 11:40:08 AM
VHF/UHF will pretty much be line of sight (plus a bit). You can't defy those laws of physics. For HF, as others have noted, don't worry too much about it unless you're gunning for #1 Honor Roll or something where you want every last dB possible to get over those mountains. My home is at 4600 feet and I have a 10000 foot mountain range just a few miles to the East of me - right in the direction of all the cool and hard-to-get DX (Europe, Africa, Middle East, etc.). I've still managed to work all over these regions with 100 watts and a terrible chunk of aluminum called a vertical and a modest beam.


Title: RE: I live in a valley
Post by: W0FM on March 15, 2013, 11:48:34 AM
Whoops, thought Cecil, typed Clint.  Brain freeze. 

Sorry Cecil.

Terry, WØFM


Title: RE: I live in a valley
Post by: N4HAL on March 15, 2013, 12:56:40 PM
I live in the mountains in a bowl. UHF & VHF work on rare occasion, but HF works quite well most of the time. Tried regular dipole antennas and later changed them to folded dipoles fed with ladder line for a significant gain in performance. Also have a 32' vertical that I switch to on occasion.
Get on the air you'll be amazed What you can do!

Bill
N4HAL


Title: RE: I live in a valley
Post by: AJ3O on March 15, 2013, 03:46:55 PM
Only have three suggestions for you:

1. Find a friend close by and setup a remote station. Not cheap
2. Move to a better location. DEFINITELY NOT cheap
3. Just try and home brew your own antennas out of wire and have fun where you are. On the nice weekends, you can take your equipment and the knowledge you gained from making your own antennas to a higher place and have a blast. CHEAPEST

You will get out and the bands will surprise you.

73,

Joe / AJ3O


Title: RE: I live in a valley
Post by: W5DXP on March 15, 2013, 06:33:03 PM
Whoops, thought Cecil, typed Clint.

"Go ahead ... make my day!":)


Title: RE: I live in a valley
Post by: K0ZN on March 15, 2013, 07:43:38 PM

If you can get your antennas up 60 to 80 ft. I would expect you will have VERY good results.....hill or not..... especially on the lower bands.
VHF can be a challenge, but up at those frequencies, if you want to make the expense and effort you can put up some large antennas that
may surprise you.

Biggest issue I see at your QTH is that you are worrying too much !!

73,  K0ZN


Title: RE: I live in a valley
Post by: WD4ELG on March 15, 2013, 07:48:06 PM
You need to contact KY6R.  He has achieved honor roll on DX and he lives in a valley east of San Fran.  He has shared his experiences, which are very insightful.


Title: RE: I live in a valley
Post by: ONAIR on March 16, 2013, 12:14:17 AM
VHF and UHF will likely present a problem, although a beam antenna could help somewhat.


Title: RE: I live in a valley
Post by: AD6KA on March 16, 2013, 12:02:20 PM
Quote
Biggest issue I see at your QTH is that you are worrying too much !!

Agreed.
Just get on the air and have fun!  ;D

Do you know how many city hams (like me) who would give
their right arm
to be able to get their antennas up 70 feet?
You are lucky my friend, count your blessings.

GL ES 73, Ken  AD6KA


Title: RE: I live in a valley
Post by: WB6BYU on March 16, 2013, 12:27:55 PM
Quote from: ONAIR
VHF and UHF will likely present a problem, although a beam antenna could help somewhat.



You may also find that pointing a beam at the surrounding hills on VHF may produce some
reflections in useful directions, or knife-edge diffraction that allows you to make contacts
out of the valley.


Title: RE: I live in a valley
Post by: G7DMQ on March 16, 2013, 05:43:19 PM
As others have said, HF isn't goi g to be a problem.

Although it sounds crazy, what about a kite?

Years ago I built a box kite with 2' cells, 6' long.  Once you get it 500' in the air, the wind was constant enough that it would just stay there!  Tie it to something solid on the ground and mount an omni directional antenna on the kite with Mini8 as the feeder.

I used mine as a sort of 'sky hook'  for an HF Vertical or sloper - and it worked pretty well.

Si


Title: RE: I live in a valley
Post by: KV7W on March 17, 2013, 05:57:56 AM
You live in an awesome place for an antenna farm. If my Google Earth is right, you have fairly flat land at 2000', surrounded by hills that go up another 2-300'. The surrounding countryside is at similar elevation. Very little man made noise in the area that I can see.

On 2m-6m I would have a blast with knife-edge diffraction at your place. Just point a Yagi at the ridge lines. Instead of building a huge tower, play around with pointing your antennas up at the ridge. I think you'll find those grassy fields around your place will have great ground plane properties after it rains.

HF? Looks like you have the room for a Rhombic if you wanted.

You don't live in a hole; a hole is a small apartment in a big city full of transformers, power lines and steel.



Title: RE: I live in a valley
Post by: KD8UXE on March 17, 2013, 06:44:32 AM
I do have room to spare here I'm trying to figure out the best way to start out.With out good antenna's my new/ old radio is a big paper weight.


Title: RE: I live in a valley
Post by: KV7W on March 17, 2013, 09:42:10 AM
You have lots of options. Just a simple dipole between building would get you started. I'm sure there's some 4" aluminum irrigation pipe in your area that a vertical could be made of with full sized ground plane. Have some telephone poles dug in that will get you up about 35' - long wire. A lot of the antenna options you are probably researching are focused toward small lots with lots of noise. You don't have to compromise!   


Title: RE: I live in a valley
Post by: KA4NMA on March 17, 2013, 12:16:37 PM
Put up the longest and highest dipole and feed with ladder line.  For vhf/uhf you could try a high beam.  One my friends, Frank k4cbw lives in the mountains of NC.  To reach a repeater in the east, he would point his antenna west, at a mountain, and bounce his signal off it.

Randy ka4nma


Title: RE: I live in a valley
Post by: KD8UXE on March 21, 2013, 05:34:36 PM
ok i found this antenna in an old antenna book does any one use a sterba curtain antenna? and would it be a good one to use in this vally.


Title: RE: I live in a valley
Post by: W5DXP on March 22, 2013, 05:54:31 AM
... does any one use a sterba curtain antenna?

http://www.w8ji.com/ham_universe_curtain.htm


Title: RE: I live in a valley
Post by: KD8UXE on March 22, 2013, 06:21:47 AM
Thank's I am going to use a dipole and a yagi and if it won't work then I will try something else.



thank's and 73s


Title: RE: I live in a valley
Post by: K5LXP on March 22, 2013, 07:14:13 AM
Thank's I am going to use a dipole and a yagi and if it won't work then I will try something else.

It's gonna work, and work well.  As others have mentioned even "impossible" VHF paths can work.  I easily work my buddy W5AOX 15 miles away from me on 2M and 440 simplex.  Doesn't seem all that remarkable until you consider there's a 5000 foot high mountain between us.

Perfection is the enemy of good enough.  Lots of hams would envy a dipole up 70 feet.  Put it up and have a blast.


Mark K5LXP
Albuquerque, NM


Title: RE: I live in a valley
Post by: KD8UXE on March 22, 2013, 01:36:15 PM
yep 6 element yagi for 2 meter and a dipole for hf.