About Us

March 27th 05, 07:29 PM

In article ,
says...

Bob Schreibmaier wrote:

Hi Tom,

In article , you say...

I haven't asked anything impossible or even tough, since I only gave a
general bound on size, gave the rough band limits desired, and said we'd
like gain and directivity.

Well... :-)

On a band that has a bandwidth of roughly 4% of
its center frequency, you're going to be REALLY
hard-pressed to get coverage of both phone and
CW on an antenna that is a little over 40% of
full size. So far, no manufacturer has been
able to come up with the antenna you describe.

Many years ago, Swan Antennas had a 2-element
40 meter beam that used half size elements.
As I recall, it used loading coils midway
through each element. I'm not very sure, but
I think the boom length was about 16 feet.
I think they got somewhere around 100 kHz
between 2:1 points. That wouldn't even cover
the entire phone band, and the elements are
longer than your design requirements.

So, yes, you are asking for something very tough,
if not impossible.

But, I wish you good luck in your quest! :-)

73,
Bob

From my original post -

"It would be desirable to have both CW and phone covered, but phone only
is ok."

From my original post -

I think they got somewhere around 100 kHz
between 2:1 points. That wouldn't even cover
the entire phone band, and the elements are
longer than your design requirements.

73,
Bob

--
+----------------------------------------------+
| Bob Schreibmaier K3PH | E-mail: |
| Kresgeville, PA 18333 | http://www.dxis.org |
+----------------------------------------------+

Thread Tools	Search this Thread
Show Printable Version	Search this Thread: Advanced Search
Display Modes
Switch to Linear Mode Switch to Hybrid Mode Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Inverted ground plane antenna: compared with normal GP and low dipole.	Serge Stroobandt, ON4BAA	Antenna	8	February 24th 11 10:22 PM
Discone antenna plans	[email protected]	Antenna	13	January 14th 05 11:51 PM
QST Article: An Easy to Build, Dual-Band Collinear Antenna	Serge Stroobandt, ON4BAA	Antenna	12	October 16th 03 07:44 PM
Ten-tec vee beam	Tom Coates	Antenna	8	September 21st 03 12:47 AM
Compact HF antenna (RX-only) for reference in antenna tests?	Crazy George	Antenna	4	September 4th 03 05:32 PM

Menu

About Us