On Mon, 05 Sep 2005 18:48:31 -0400, Ham op wrote:


Fred and Hamop, Thanks for your help. I think about 82ft or so for the 80
meters, for an inverted V. Basically, the same size as the Alpha Delta DX-CC at
80 meters,

http://www.alphadeltacom.com/dxcc_ii.htm

but that antenna has been on backorder since March. It would be much easier to
hang an 82 foot antenna, as opposed to 120 feet. I have an Imax-2000 that I use
on 10-12-15-17meters, as well as my CB for the locals. I have an Icom 746 that
seems to tune at 17 meters fine with that antenna, but that is about the
bandwidth. I have made DX contacts at 17. That antenna is primarily connected to
my Grant LT CB for chatting with locals, but I read the review on eham.net, and
tried on on 10-12-15-17. The 746 tuner worked perfectly. I was able to make
contacts on 10 and 17, but none on 12 and 15, mostly because those bands were
dead. So if I can use it on those bands, then I only need a 80-40-20 inverted V.


You are correct and asked the proper question.

HOW SHORT DO YOU WANT THE FINAL ANTENNA TO BE??

Fred McKenzie wrote:
In article , Vinnie S.
wrote:

Thanks for all the responses, but I seem to be more confused because it

seemed I

got differing opinions. As I said, I am a beginner at antenna theory. The
frequencies I am trying to make an antenna for, are centered at 3.875, 7.225,
and 14.250. Those are the center for the phone frequencies on the US bands. I
wanted to shorten the 80 meter band antenna. I would have kept the 40

and 20 at

the specified lengths. I guess I will buy the ARRL book. But they also make a
long wire classic book. I might get that instead. .


Vinnie-

One thing isn't clear. How short do you need the total length to be?

I think everyone is in agreement that a trap dipole is shorter on the
lower band than a simple dipole would be for that band. The trap acts
like an inductor below its resonant frequency, so the part of the antenna
beyond the trap is electrically lengthened on the lower band(s).

Therefore, the 20 Meter traps would be at the proper places, around 16
feet each side of center. However, the 40 Meter traps would be closer to
the center than for a simple dipole, due to the inductive effect of the 20
Meter traps. Similarly, the added wire for 80 Meters is less than for a
simple dipole due to both the 20 and 40 Meter traps' inductance.

You may find that the resulting length of a dipole with both 20 and 40
Meter traps, is short enough for your needs.

73, Fred, K4DII


Vinnie S.

For design of 2-frequency trapped dipoles, including traps, download
program TRAPDIP from website below.

First enter in the program the two frequencies and the overall length
you would like the antenna to be.
----
.................................................. ..........
Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
.................................................. ..........

Vinnie S. wrote:

On Mon, 05 Sep 2005 18:48:31 -0400, Ham op wrote:


Fred and Hamop, Thanks for your help. I think about 82ft or so for the 80
meters, for an inverted V. Basically, the same size as the Alpha Delta DX-CC at
80 meters,

SNIPPED to save bandwidth and reading time.

Vinnie, you will find what you need, assuming you are not intimidated by
running a free program on your computer at the site given by Reg earlier.

I quote from his post on your thread:

"Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp"

Look at "TRAPDIP" and "TRAP3" for starters.

Good Luck, HamOp

On Tue, 06 Sep 2005 07:34:11 -0400, Ham op wrote:

Vinnie S. wrote:

On Mon, 05 Sep 2005 18:48:31 -0400, Ham op wrote:


Fred and Hamop, Thanks for your help. I think about 82ft or so for the 80
meters, for an inverted V. Basically, the same size as the Alpha Delta DX-CC at
80 meters,

SNIPPED to save bandwidth and reading time.

Vinnie, you will find what you need, assuming you are not intimidated by
running a free program on your computer at the site given by Reg earlier.

I quote from his post on your thread:

Thanks !


"Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp"

Look at "TRAPDIP" and "TRAP3" for starters.

Good Luck, HamOp


Vinnie S.