There was a discussion the other day about stub loaded
dipoles. A 30m dipole loaded at each end with a 30m/4
shorted stub is resonant on both 30m and 75m. A 17m
dipole loaded at each end with a 17m/4 shorted stub
is resonant on both 17m and 40m. The stubs provide
inductive loading on the lower bands resulting in
"shorty" dipoles, shrunk by about 20%.

I've summarized two such antennas on my web site at:

http://www.w5dxp.com/dualband.gif
--
73, Cecil http://www.w5dxp.com

On May 20, 4:51�pm, Cecil Moore wrote:
There was a discussion the other day about stub loaded
dipoles. A 30m dipole loaded at each end with a 30m/4
shorted stub is resonant on both 30m and 75m. A 17m
dipole loaded at each end with a 17m/4 shorted stub
is resonant on both 17m and 40m. The stubs provide
inductive loading on the lower bands resulting in
"shorty" dipoles, shrunk by about 20%.

I've summarized two such antennas on my web site at:

http://www.w5dxp.com/dualband.gif
--
73, Cecil �http://www.w5dxp.com

Hi Cecil, How do you model the 1/4wl 3" stubs on the ends of the
dipole? I have EZNEC 4.0.
Gary N4AST

wrote:
Hi Cecil, How do you model the 1/4wl 3" stubs on the ends of the
dipole? I have EZNEC 4.0.

It's actually 0.3 ft, i.e. 3.6 inches. The EZNEC file is at:

http://www.w5dxp.com/40_17.EZ
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:

It's actually 0.3 ft, i.e. 3.6 inches. The EZNEC file is at:

http://www.w5dxp.com/40_17.EZ

Dead link?


Craig 'Lumpy' Lemke

www.n0eq.com

Lumpy wrote:
Cecil Moore wrote:

It's actually 0.3 ft, i.e. 3.6 inches. The EZNEC file is at:

http://www.w5dxp.com/40_17.EZ

Dead link?

Seems to be OK this morning - and the spacing is
0.25 ft, i.e. 3 inches.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
... The EZNEC file is at:

http://www.w5dxp.com/40_17.EZ


Lump:
Dead link?


Cecil:
Seems to be OK this morning - and the spacing is
0.25 ft, i.e. 3 inches.


Got it now. Thanks.

Craig 'Lumpy' Lemke

www.n0eq.com

"Cecil Moore" wrote in message
news
There was a discussion the other day about stub loaded
dipoles. A 30m dipole loaded at each end with a 30m/4
shorted stub is resonant on both 30m and 75m. A 17m
dipole loaded at each end with a 17m/4 shorted stub
is resonant on both 17m and 40m. The stubs provide
inductive loading on the lower bands resulting in
"shorty" dipoles, shrunk by about 20%.

I've summarized two such antennas on my web site at:

http://www.w5dxp.com/dualband.gif
--
73, Cecil http://www.w5dxp.com
It might be easier to do what I did. I have 17 and 40 meter dipoles
connected to a common feedpoint. The 17 m dipole is the supporting element,
hung between two trees at about 50 feet. The 40 m dipole is arranged as an
inverted V. The trees are not far enough apart to have the 40 m dipole on
top. Either way, the 40 m has to be resonated first.

Tam/WB2TT

Tam wrote:
It might be easier to do what I did. I have 17 and 40 meter dipoles
connected to a common feedpoint.

Now your challenge is to turn it into a 40m
rotatable beam. Have a look at:

http://www.w5dxp.com/4017beam.EZ
--
73, Cecil http://www.w5dxp.com