On Wed, 6 Feb 2013 22:08:02 +0000, Channel Jumper
wrote:


'Tom[_8_ Wrote:
;801430']Hi all

Now I need a recommendation for a 2m 70cm base antenna. This will go
right
at the top of a 50ft tower. My ringo 2m modification antenna didn't pan
out
too well. I could get low SWR on some freq but I want a wider range of
work.
If that is possible. I also use it for 156 megs (Marine band).

I am looking at the utubes of dual band antennas for home, I like the
UVS-300.

Can anyone make a recommendation for the purchase of a dual band
antenna? I
would also like to use it as a SWL antenna as I listen a lot on all
bands.
This antenna will be verticle and right at the top of the tower. I am
hoping
to spend about 200 dollars.

Thanks for any comments,

The antenna of choice is the Diamond X 510 fed with Belden 9913 or LMR
400

Ringo's are nothing more then a over glorified dummy load..

Second choice would be a Diamond V2000 if you also wanted to include 6
meters.....

On two meters FM - I have talked up to 1500 miles when the bands were
open with the Diamond V2000 and frequently talk 50 / 75 miles in the
mountains of western Pennsylvania - although my elevation helps a
little.

I am at 1400' amsl - 60 miles west of State College and 65 miles east of
Pittsburgh and I can talk and listen - north, south, east and west
about 50 miles full quieting.


Do not take the Diamond X510, take a shorter one.
The long antenna bends and swayes in the wind causing unnecessary
fading. The bending results in early failure.

You cannot SWL with a real duoband antenna, because it is frequency
selective and is dead on the SW bands.

w.

Ya - I didn't catch that one.
Longer wavelengths requires a larger antenna, hence you aren't going to use a 2 meter antenna to listen to 80 or 160 meters - at least you probably aren't going to work much DX - but the bottom line is - you need more then one antenna to do everything...

MIght I suggest the Barker and Williamson BWD 90 folded dipole for the HF bands. Problem is - it costs more then 200 dollars.

The Diamond X510 should not give you much problems with bending - opposed to what Wabnig sez...

Technicially, you should never put a vertical antenna at the very top of any tower. You should side mount it - which would eliminate any bending or flexing. Putting it at the top of the tower - just turns it into a good lightning rod.

Not to get too technicial, but the title of the post was Dual Band Antenna ???
Not one antenna that does it all.

The only antenna that does more then one or three bands would be the discone antenna...

The Diamond Discone will operate somewhere between 10 meters and 900 MHz.

Any other antenna would require the use of traps or solenoids to make the antenna resonant for that band.

One other antenna - if you had the money and the real estate would be the High Power - Off Center Fed Dipole - which operates practically everywhere between 440 MHz and 160 meters - with the exception of 15 and 30 meters.

http://www.angelfire.com/electronic/hypower/

On 2/8/2013 8:24 AM, Channel Jumper wrote:

One other antenna - if you had the money and the real estate would be
the High Power - Off Center Fed Dipole - which operates practically
everywhere between 440 MHz and 160 meters - with the exception of 15 and
30 meters.

http://www.angelfire.com/electronic/hypower/

If you believe that an antenna will operate effectively from 160m to
70cm you are even more ignorant than I previously thought.

And OCFD are not good even at HF if you really understand how they work
and the problems they have because of that.

tom
K0TAR

On Fri, 08 Feb 2013 20:26:03 -0600, tom wrote:

If you believe that an antenna will operate effectively from 160m to
70cm you are even more ignorant than I previously thought.

Yep. To paraphrase Roy Lewallen (W7EL):
Small size, broadband, gain.... pick any two.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"tom" wrote in message
...

And OCFD are not good even at HF if you really understand how they work
and the problems they have because of that.

tom
K0TAR



Tom have you ever compaired the OCF to other antennas at your house ?

I have. I have up an 80 meter dipole and OCF at right angles to each other
at about 50 to 60 feet on each end. There is not much differance in the two
on 80 except in the favored directions.

Also is a 3 element tribander at 60 feet. On 20 and 10 meters there is not
really that much differance on the stateside stations either when the
stations are in the direction the OCF favors. There is a big differance in
the directions that the OCF does not favor as it should be.
If I could only put up a dipole nonrotating antenna, that would still be the
results.

Now granted the OCF will not work all that well above 10 meters, and there
are some low bands such as 15 meters it will not work well as the swr is
very high.

The OCF I am using is a home made Carolina Windom type for 80 meters and
above.

de KU4PT

On 2/8/2013 9:50 PM, Ralph Mowery wrote:
"tom" wrote in message
...

And OCFD are not good even at HF if you really understand how they work
and the problems they have because of that.

tom
K0TAR



Tom have you ever compaired the OCF to other antennas at your house ?

I have. I have up an 80 meter dipole and OCF at right angles to each other
at about 50 to 60 feet on each end. There is not much differance in the two
on 80 except in the favored directions.

Well, since a 3 element tribander would have less than an S unit over a
dipole or an OCF I would expect you're correct in stating you can see
almost no difference. They still have problems.

tom
K0TAR

"tom" wrote in message
...
Well, since a 3 element tribander would have less than an S unit over a
dipole or an OCF I would expect you're correct in stating you can see
almost no difference. They still have problems.

tom
K0TAR


Again I ask, have you ever used an OCF ?

Also what problems do they have that other antennas do not have as long as
they are used on the bands they are designed for ?

I am going to explain it, but only once.
If you talk to the owner of that web site, he will tell you that the designer of the particular model of off center fed dipole that I am talking about is K3CC.
Again, if you call him on the phone, he will explain to you that K3CC holds 27 US patents and is a lot more intelligent then you will ever be.


A off center fed dipole is not a balanced antenna, but exhibits some properities not found in a regular old dipole.

Reguardless of it's length - you can always find someplace where it is resonant. Its SWR is flat as a board on most bands and is below 2:1 most everywhere else with the exception of 15 and 30 meters........

The neatest thing I ever heard was from a old Motorola Technician who told me two important things.
First was that God gave us two ears and only one mouth.
That means we should listen twice as much as we should speak.

Second was that when a manufacturer makes a radio, they make the most important knob the largest knob - hence the tuning knob is the largest knob on the radio.
If you don't like what you hear - you turn the knob.

I was under the impression that this person was a HAM and wanted to talk as well as listen.
Then we got into a discussion about scanners.
Now I am confused.

With any type of communications - if a pager is suspect and it interferes with amateur radio, you can either A - turn the operator of the pager into the FCC for interfering with amateur radio communications - good luck, or you can add filtering.

Even some two meter repeaters operates illegally, because their signals splatter all over other peoples repeaters.. We need to remember that repeaters are not built and owned by the government or industry, but by regular old ham radio operators like you and me.

As far as analog scanners goes, you sure can't beat a Uniden 890XLT...
Even unmodded, it should hold 200 channels, and has a very sensitive receive.

Moving up to a dedicated transceiver - that can be used as a all band scanner, you could purchase a Yaesu 8900 which does everything from 10 meters to 800 MHz.... At about $450 new, and with a slight modification - resistor removal, will transmit 28 - 29 Mhz, 50 - 54 MHz, 140 - 148 Mhz, 430 - 460 Mhz. and will listen everywhere else.

If you don't have a ham license, then just put the microphone away and listen.

It's pretty hard to listen when you are talking, and it is pretty hard to compare one antenna to another when you do not have that particular model of antenna there in front of you and in operation at the same time.
And it is not fair to compare one antenna to another when they are not aimed in the same direction.
Antenna comparisons are made at the same time, within one hour of each other and in the same location and height....

http://www.k3cc.net/