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: For stealth purposes... Hamstick groundplane antenna?  (Read 5606 times)
KG4WXP
Member

Posts: 165




Ignore
« on: December 04, 2011, 09:39:46 AM »

Since I'm trying to be somewhat stealthy, not to mention having fun experimenting, could I use a hamstick antenna (or one of the 4 ft workman cb helical wound antennas with some of the wire cut off) for 10 meters, into some sort of a mount (this is meant as a fixture on the back of the house or on a mast attached to the back of the house) and put wires somewhere running off of it to make a makeshift ground plane?

How well would this work, as it'd be loaded via a helical wound primary element (or top loaded if I got a top adjustable antenna like the Firestik) as opposed to say... a 102" whip cut for 10m with radials?

It'd be used for both local (within 10 miles) and contacts around the US, I wouldn't figure it would work well for long range contacts.

Thanks in advance!

Chris
« Last Edit: December 04, 2011, 09:41:17 AM by KG4WXP » Logged
KG4NEL
Member

Posts: 373




Ignore
« Reply #1 on: December 04, 2011, 09:42:50 AM »

Since I'm trying to be somewhat stealthy, not to mention having fun experimenting, could I use a hamstick antenna (or one of the 4 ft workman cb helical wound antennas with some of the wire cut off) for 10 meters, into some sort of a mount (this is meant as a fixture on the back of the house or on a mast attached to the back of the house) and put wires somewhere running off of it to make a makeshift ground plane?

How well would this work, as it'd be loaded via a helical wound primary element (or top loaded if I got a top adjustable antenna like the Firestik) as opposed to say... a 102" whip cut for 10m with radials?

It'd be used for both local (within 10 miles) and contacts around the US, I wouldn't figure it would work well for long range contacts.

Thanks in advance!

Chris

For 10 meters, you're not shortening the antenna by that much - so it won't be as affected as, say, a 20 meter version.

Locally, polarization can make a big difference; if most of the people near you are running horizontal polarization from dipoles, you may not hear them very well.
Logged
KG4WXP
Member

Posts: 165




Ignore
« Reply #2 on: December 04, 2011, 09:48:45 AM »

For 10 meters, you're not shortening the antenna by that much - so it won't be as affected as, say, a 20 meter version.

Locally, polarization can make a big difference; if most of the people near you are running horizontal polarization from dipoles, you may not hear them very well.

Most of my local buddies use verticals on 10 meters as well so it shouldn't be an issue.... so you think it'd work well for local? great!

What about the other side of the equation; ie stateside contacts (and maybe the occasional euro station)?
Logged
KG4WXP
Member

Posts: 165




Ignore
« Reply #3 on: December 04, 2011, 10:44:44 AM »

Also, what type of mount would be best to use to mount the antenna on a mast, and where would i run the ground wires from?
Logged
WB6BYU
Member

Posts: 13335




Ignore
« Reply #4 on: December 04, 2011, 11:06:25 AM »

Local work will be helped by getting it up as high as possible.  That doesn't make as much
of a difference for long distance propagation.

Many CB antennas will work on 10m without and adjustment, the rest might need to be
shortened a bit.  Check the SWR first and see.  If it has an adjustable top section, see if
that has enough range, otherwise you often can replace it with copper wire and just clip
it off to find the right length.  (That is often faster than trying to trim the stainless whips
a bit at a time.)  If it is a straight helical winding then pull a couple turns of wire at a time
out the top and snip them off while checking the SWR.

There are LOTS of different mounts available - I'd say use whatever sort you have handy
that you can find some way to fit.  For example, I have a couple of the ones that clamp to
a rail and they often can be rotated and screwed to a deck railing, etc.

If the antenna is close to the house siding it may change the tuning, and performance will
be more dependent on the building materials.  That's why something like a balcony is useful
where you can install it so it isn't against a wall.

Performance won't be as good as a full quarter wave whip, but not too bad.  You might see
a 3dB loss with a 4' helical whip.  Try to use as long of an antenna as possible - generally
the more you shorten it, the less the efficiency.

The radials need to connect right to the mounting bracket at the base of the antenna where
the coax plugs in.  Probably the simplest approach is to put a lug under the mounting screws.


When 10m is open you may be surprised at the DX you can work with relatively low power.
Logged
K2DC
Member

Posts: 1373


WWW

Ignore
« Reply #5 on: December 04, 2011, 11:08:55 AM »

What you want is a ground plane.  Three or 4 1/4 wavelength radials from the ground side at the base of the Hamstick if it's mast mounted, and sloping downward.  OR - You can buy a ground-mounted tripod like the Alpha Delta Outpost:

http://www.outbackerantennas.com/outpost.html

It weighs about 20 pounds and costs $275.  OR better yet, build one of your own as I did.  I used 1/8" thick by 1/2" angle stock for the legs and the fold-out ground couplers.  The tripod stand about 3' tall, and I used lamp chain half way up between each leg to set the height of the tripod.  A small peice of aluminum flat stock is at the top using small hinges to connect to the legs, and an SO-239-to-3/8-24 adapter in the middle to connect the Hamstck.  The whole thing weighs about 2 pounds and cost me about $25 for materials, mostly from Home Depot.  It folds up small enough to fit in a large fishing pole carrier.  My 20M and 15M Hamsticks both matched better on the tripod than they did on the car.

73,

Don, K2DC
Logged
WE1X
Member

Posts: 338




Ignore
« Reply #6 on: December 04, 2011, 02:00:33 PM »

Why not get 2 Hamsticks and make a dipole? Still would be stealthy and probably a better performer.

Harry WE1X
Logged
ONAIR
Member

Posts: 1744




Ignore
« Reply #7 on: December 04, 2011, 06:06:43 PM »

Since I'm trying to be somewhat stealthy, not to mention having fun experimenting, could I use a hamstick antenna (or one of the 4 ft workman cb helical wound antennas with some of the wire cut off) for 10 meters, into some sort of a mount (this is meant as a fixture on the back of the house or on a mast attached to the back of the house) and put wires somewhere running off of it to make a makeshift ground plane?

How well would this work, as it'd be loaded via a helical wound primary element (or top loaded if I got a top adjustable antenna like the Firestik) as opposed to say... a 102" whip cut for 10m with radials?

It'd be used for both local (within 10 miles) and contacts around the US, I wouldn't figure it would work well for long range contacts.

Thanks in advance!

Chris
  10 Meters is really open now.  A home made ground plane will allow you to work the locals, or work the world!  If you want, you can pick up an A-99 for around $50 bucks, mount it at or near ground level, and you should be quite happy with the results.  Slip a 20 foot PVC pipe over it, hang a flag on the pipe, and no one will ever know that it is there!
Logged
KG4RUL
Member

Posts: 2734


WWW

Ignore
« Reply #8 on: December 04, 2011, 06:15:25 PM »

I use two MFJ Hamtennas - This is the 10M version:  http://www.mfjenterprises.com/Product.php?productid=MFJ-1610T in one of the MFJ dipole mounts: http://www.mfjenterprises.com/Product.php?productid=MFJ-347 

This can also be bought as a package: http://www.mfjenterprises.com/Product.php?productid=MFJ-2210

Mount it about 15 feet up and rotate by hand - an inexpensive and well functioning setup.
Logged
KD6KWZ
Member

Posts: 276




Ignore
« Reply #9 on: December 04, 2011, 10:07:46 PM »

Right now, I only have a RS HTX-10 for HF, so 10 meters only at the moment.

I did see this, but have not tried this model of Wilson FGT (2 foot):

http://www.hamuniverse.com/kl7jr10meterstealth.html

Other Wilson FGT models tested on Ham bands:

http://www.hamuniverse.com/kl7jrcbverticals.html

I've tried a Wilson FGT-5 (5 foot) with various tips, but it is very touchy to get a low SWR with a tuner.
I might be too close to the ground for it. I may also need an antenna analyzer.

I'm also using this Delta Loop in Configuration (C):

http://www.w5sdc.net/delta_loop_for_hf.htm

I'm using 2 fiberglass tent poles, with 28 gauge wire. I can get the US without much trouble, when the
band is open, with 22 watts PEP SSB. I have contacted JE7JKS & UA0KBU with it, as well.

73, Mike
Logged
WA3SKN
Member

Posts: 5496




Ignore
« Reply #10 on: December 05, 2011, 01:17:48 PM »

Shortening or loading the antenna affects bandwidth.  For 10 meters, I do not see a need to shorten... 8 ft 3 in per side on a dipole is not too big, and does not take much to get it over 1/2 wavelength high, either!
A little coax and a 16 ft dipole strung between two supports makes a dandy antenna, and 10 meters has been open lately into the night!
73s.

-Mike.
Logged
W7DKE
Member

Posts: 8




Ignore
« Reply #11 on: December 08, 2011, 03:26:24 PM »

Why not homebrew a simple dipole and hang one end of it from a tree branch?  That's what I do and get great results.  About $20 in parts (copper wire, center insulator, end insulators) and about a hour to construct and hang from the tree.  The low end is about 6 feet off the ground.  I've been talking to Japan and Australia and elsewhere this week no problem with 100W.  It ought to do a lot better than a 4' loaded antenna or the classic 8' 1/4 wave, and it's CHEAP.  Just make sure your feedline comes out at 90 degrees or close to it for as long of a distance as possible to avoid coupling.  And no one has any idea it's there...it's inside the canopy of a spruce tree Roll Eyes
Logged
STAYVERTICAL
Member

Posts: 875




Ignore
« Reply #12 on: December 09, 2011, 07:23:32 PM »


On 10m any bit of wire will work fine.
In fact I would not bother with a helically wound fibreglass antenna, but would just use a bit of wire between any two convenient anchor points.
This will probably work much better than a long RF choke, which is what a helically wound antenna really becomes.
From my experiments I would also use a top loaded solution in place of a helically wound antenna, as this is far more efficient in most cases.

I am not sure of your situation, but if its possible, I would consider buying a remote ATU.
This will make your ham life infinitely simpler and banish the tedium of matching the antenna to the feedline for a wide range of frequencies.
With this solution, you simply route your antenna where you wish, to make it as stealthy as possible, and press the tune button to get a good swr match over a wide range of frequencies.

This means you will be frequency agile and able to leverage changing propagation conditions, and concentrate on antenna efficiency, radiation pattern and experimentation, rather than spending hours trying to match the antenna to the feedline.

Just a thought.

73s
Logged
KE3WD
Member

Posts: 5689




Ignore
« Reply #13 on: December 09, 2011, 07:30:40 PM »

Why not get 2 Hamsticks and make a dipole? Still would be stealthy and probably a better performer.

Harry WE1X

That is what I would suggest also. 


73
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!