Newbie antenna help
 

New to ham radio. Interested in building an antenna for a base station.
I dont have anything yet, just in the planning stage.


Thought about buying a handheld and using that as part of my "base
station" one maybe capable of 2 440 and 6. These seem cheaper used than
the home units.


My question is, is there information out there on how to build one? I
have a radio shack book at home that has a plan for a 440. It uses
aluminum ground wire. What I find when working with this stuff is it is
impossible to make it perfectlyu straight. Doesn't that effect the
performance? I mean it comes coiled and when I cut it to length I cant
get it perfectly straight.


Also, it is posisble to have good performance with one antenna for all
the bands? Or is it absolutely necessary to have one antenna for each
band? I have limited room.


I appreciate your help!

wrote in message
ups.com...
New to ham radio. Interested in building an antenna for a base station.
I dont have anything yet, just in the planning stage.


Thought about buying a handheld and using that as part of my "base
station" one maybe capable of 2 440 and 6. These seem cheaper used than
the home units.


Yes the handhelds are cheaper but they have a lot less power. However if
your antenna is high enough, you can do amazing things with it.


My question is, is there information out there on how to build one? I
have a radio shack book at home that has a plan for a 440. It uses
aluminum ground wire. What I find when working with this stuff is it is
impossible to make it perfectlyu straight. Doesn't that effect the
performance? I mean it comes coiled and when I cut it to length I cant
get it perfectly straight.


It doesn't have to be perfectly straight. You won't notice any difference
unless you have loops coiled in it.


Also, it is posisble to have good performance with one antenna for all
the bands? Or is it absolutely necessary to have one antenna for each
band? I have limited room.


Yes there are multiband antennas. Basically, they use some type of coil or
trap to subdivide the antenna. The full length of the antenna is used for
the lowest frequency, etc.

Dee D. Flint, N8UZE

Dee Flint wrote:
wrote in message
ups.com...
New to ham radio. Interested in building an antenna for a base
station.
I dont have anything yet, just in the planning stage.


Thought about buying a handheld and using that as part of my "base
station" one maybe capable of 2 440 and 6. These seem cheaper used
than
the home units.


Yes the handhelds are cheaper but they have a lot less power.
However if
your antenna is high enough, you can do amazing things with it.


My question is, is there information out there on how to build one?
I
have a radio shack book at home that has a plan for a 440. It uses
aluminum ground wire. What I find when working with this stuff is
it is
impossible to make it perfectlyu straight. Doesn't that effect the
performance? I mean it comes coiled and when I cut it to length I
cant
get it perfectly straight.


It doesn't have to be perfectly straight. You won't notice any
difference
unless you have loops coiled in it.


Also, it is posisble to have good performance with one antenna for
all
the bands? Or is it absolutely necessary to have one antenna for
each
band? I have limited room.


Yes there are multiband antennas. Basically, they use some type of
coil or
trap to subdivide the antenna. The full length of the antenna is
used for
the lowest frequency, etc.

Dee D. Flint, N8UZE

What would you recommend? Building a beam for two meter? If I did that
would it work ok on 440 too?

Also, I have seen beams mounted bothe on it's side and upright like an
outside tv antenna. Which way is better?

On 21 Dec 2004 05:43:59 -0800, wrote:

What would you recommend? Building a beam for two meter? If I did that
would it work ok on 440 too?

Hi OM,

Beams add complications for a newbie, stick with a simple vertical
until you both need and can afford these. Concentrate on the simple
maxim: Higher is Better.

Also, I have seen beams mounted bothe on it's side and upright like an
outside tv antenna. Which way is better?

This is the complication - both are better... depending on what you
want to do. What you want to do depends on your local Ham activity
so, as you can see, the list of constraints grows in front of you.
Simply put up a cheap antenna (one you build yourself) and let events
drive your choices from there.

73's
Richard Clark, KB7QHC

Here is some antenna theory to read to answer your questions
URL:
http://k9erg.tripod.com/theory.htm

--
Caveat Lecter

"Caveat Lector" wrote

Here is some antenna theory to read to answer your questions
URL:
http://k9erg.tripod.com/theory.htm

Nice site. Except for the inaccurate advice warning of disastrous effects
from operating a J-Pole w/o a BalUn. I use neither a BalUn nor any
coiled-feedline as a choke. If my feedline is radiating, it's the most
efficient feedline radiator ever made, getting loud and clear 100 mile
coverage on VHF Marine between other high sites, and surface contacts
between 20-30 nautical miles depending on height of vessels antenna.
Another misconception about J-Poles is from at least one web-site offering
plans, in which the offerer warned against grounding the antenna. Dangerous
and wrong of course, as the antenna and its mast should be grounded and
performs very well as such. The stub-capped tops of a copper-pipe J-Pole
antenna at the highest point of a structure will indeed be an air terminal
for lightning that was going to strike that immediate area anyway. Maybe my
lightning down conductors heading 180 degrees from the J-Pole to series of
ground rods are the SECRET G.
--
Users considering a static and lightning-grounded (and un-choked) J-Pole
should make sure the British did not already invent/patent this form of
improvement to the J-Pole radiation pattern. ;-)
--

73,
Jack

wrote in message
oups.com...

Dee Flint wrote:
wrote in message
ups.com...
New to ham radio. Interested in building an antenna for a base
station.
I dont have anything yet, just in the planning stage.


Thought about buying a handheld and using that as part of my "base
station" one maybe capable of 2 440 and 6. These seem cheaper used
than
the home units.


Yes the handhelds are cheaper but they have a lot less power.
However if
your antenna is high enough, you can do amazing things with it.


My question is, is there information out there on how to build one?
I
have a radio shack book at home that has a plan for a 440. It uses
aluminum ground wire. What I find when working with this stuff is
it is
impossible to make it perfectlyu straight. Doesn't that effect the
performance? I mean it comes coiled and when I cut it to length I
cant
get it perfectly straight.


It doesn't have to be perfectly straight. You won't notice any
difference
unless you have loops coiled in it.


Also, it is posisble to have good performance with one antenna for
all
the bands? Or is it absolutely necessary to have one antenna for
each
band? I have limited room.


Yes there are multiband antennas. Basically, they use some type of
coil or
trap to subdivide the antenna. The full length of the antenna is
used for
the lowest frequency, etc.

Dee D. Flint, N8UZE

What would you recommend? Building a beam for two meter? If I did that
would it work ok on 440 too?


I'm not into a lot of VHF/UHF work personally however my OM likes loop
antennas. However loops don't have any significant gain unless you stack
them. Many people do like beams and some build their own. There are MANY
good antenna books available from the ARRL. Start with The ARRL Antenna
Book. As for working on more than one band, only those designed with that
in mind will work adequately on two bands. If it is designed for only one
band, it will be very bad on the other.

Also, I have seen beams mounted bothe on it's side and upright like an
outside tv antenna. Which way is better?


Vertical elements on beams will yield vertical polarization and are thus
suitable for repeater work and a lot of FM simplex.

Horizontal elements will yield horizontal polarization and are thus suitable
for weak signal work such as working distant SSB stations (horizontal is the
custom on SSB).

You really need to get and read a good antenna book. A newsgroup cannot
give you enough detail.

Dee D. Flint, N8UZE

Jack Painter wrote:

Nice site. Except for the inaccurate advice warning of disastrous effects
from operating a J-Pole w/o a BalUn. I use neither a BalUn nor any
coiled-feedline as a choke. If my feedline is radiating, it's the most
efficient feedline radiator ever made, getting loud and clear 100 mile
coverage on VHF Marine between other high sites, and surface contacts
between 20-30 nautical miles depending on height of vessels antenna. . .

The problem is that without the balun, the feedline is part of the
antenna. So anyone trying to get the same results as you do has to use
the same length of feedline, position it the same, and maybe even ground
his rig the same way you do. (That is, have the same path from the rig
to the Earth through the power wiring.) If he does it differently and
happens to not be as lucky as you, he could take a bit of a beating in
field strength. And both of you could be running the risk of causing RFI
if you're running significant power and your feedline runs close to
house or telephone wiring.

If a balun is used (actually, two are likely necessary, spaced about a
quarter wavelength apart), only the J-Pole will radiate, and the user
won't have to worry about lucking out and having just the right feedline
and orientation.

I think the reason some people love J-Poles and some hate them is that
some, like you, have been lucky with feedline length and placement and
some haven't. I prefer to depend on design rather than luck to make my
antennas work, but lots of folks are perfectly happy to just roll the dice.

Roy Lewallen, W7EL

For two meters and 440 I would suggest a J-pole. If you look on the arrow
antenna site http://www.arrowantennas.com/j-pole.html
He gives you the information to build your own. FM by mutual agreement is
vertical where sideband is horizontal. This relationship is used on VHF and
UHF.

On 6 meters a simple dipole will get you started. Use the formula
468/desired frequency in MHz equals the total wire length in feet. Make it a
little longer for adjustment purposes then cut it in half. Add a center
insulator and end insulators. At low power (=100 watts) use pieces of PVC
pipe. Tie the shield of the coax to one side of center and the center
conductor to the other.

Welcome to amateur radio and if I can help you in any way just e-mail me.

73 Fred

wrote in message
ups.com...
New to ham radio. Interested in building an antenna for a base station.
I dont have anything yet, just in the planning stage.


Thought about buying a handheld and using that as part of my "base
station" one maybe capable of 2 440 and 6. These seem cheaper used than
the home units.


My question is, is there information out there on how to build one? I
have a radio shack book at home that has a plan for a 440. It uses
aluminum ground wire. What I find when working with this stuff is it is
impossible to make it perfectlyu straight. Doesn't that effect the
performance? I mean it comes coiled and when I cut it to length I cant
get it perfectly straight.


Also, it is posisble to have good performance with one antenna for all
the bands? Or is it absolutely necessary to have one antenna for each
band? I have limited room.


I appreciate your help!

"Roy Lewallen" wrote
Jack Painter wrote:

Nice site. Except for the inaccurate advice warning of disastrous
effects
from operating a J-Pole w/o a BalUn. I use neither a BalUn nor any
coiled-feedline as a choke. If my feedline is radiating, it's the most
efficient feedline radiator ever made, getting loud and clear 100 mile
coverage on VHF Marine between other high sites, and surface contacts
between 20-30 nautical miles depending on height of vessels antenna. . .

The problem is that without the balun, the feedline is part of the
antenna. So anyone trying to get the same results as you do has to use
the same length of feedline, position it the same, and maybe even ground
his rig the same way you do. (That is, have the same path from the rig
to the Earth through the power wiring.) If he does it differently and
happens to not be as lucky as you, he could take a bit of a beating in
field strength. And both of you could be running the risk of causing RFI
if you're running significant power and your feedline runs close to
house or telephone wiring.

If a balun is used (actually, two are likely necessary, spaced about a
quarter wavelength apart), only the J-Pole will radiate, and the user
won't have to worry about lucking out and having just the right feedline
and orientation.

I think the reason some people love J-Poles and some hate them is that
some, like you, have been lucky with feedline length and placement and
some haven't. I prefer to depend on design rather than luck to make my
antennas work, but lots of folks are perfectly happy to just roll the
dice.

Roy Lewallen, W7EL

Hi Roy, thanks for the comments. It certainly may be luck as you say, but if
so it is exceptional luck ;-) 25 watt marine transceivers rarely perform
as well as mine does in this setup. So well that it is highly unlikely that
the sixty odd feet of 9913 feedline radiates much if at all. The original
configuration had the horizontal (with later vertical drops to ground rods)
lightning down conductors added last year, replacing a simple static ground.
Coaxial lightning surge arrestor was also added, with shield-grounding. None
of these alterations made any noticeable change in the antenna's long range
receive and transmit performance. There never was any connection between the
transceiver and AC power, using instead a 12vdc deep cell battery with a 12v
charger floating the battery.

73,
Jack Painter