HF Antenna Options
 

[Sorry if this is a repeat post. The first didn't seem to go through.]

I'm a neophyte here, but I've done quite a bit of reading on antenna
characteristics and design. Still, I'd appreciate some advice from the
more knowledgeable (that's pretty much anybody here).

1. I have pretty limited options for a serviceable antenna for, say,
40 to 10 meters. Right now, I am interested in CW only using QRP rigs
(homebrew) for DX QSO's.

2. I want to limit the visual impact, so unless you advise strongly in
favor of them I want to avoid verticals. I don't have code or covenant
restrictions, but I do have a wife.

3. Here's the physical situation: My suburban property has two houses
on it but no real trees I could use as anchor points. However, from
peak of the big house to that of the guest house I can get about 96
feet. The big-house peak is about 25 feet high and the guest house
about 13. For visual purposes, I'd like to use as thin a wire as
possible.

4. Here's my idea: an end-fed wire with traps for multi-band use. I
don't see how I could use a center-fed dipole unless the feeder came
back parallel (right next to) along one leg of the dipole. In other
words, I can't feed at perpendicularly. For a variety of reasons, the
azimuth of a wire line between the two houses would be about 25
degrees/205 degrees.

So . . . what do you think? What kind of performance do you think I
could expect from this setup?

Many thanks! ---Todd

HF Antenna Options
 

On Sat, 6 Aug 2011 13:44:43 -0700 (PDT), Todd Carney
wrote:

[Sorry if this is a repeat post. The first didn't seem to go through.]

I'm a neophyte here, but I've done quite a bit of reading on antenna
characteristics and design. Still, I'd appreciate some advice from the
more knowledgeable (that's pretty much anybody here).

1. I have pretty limited options for a serviceable antenna for, say,
40 to 10 meters. Right now, I am interested in CW only using QRP rigs
(homebrew) for DX QSO's.

2. I want to limit the visual impact, so unless you advise strongly in
favor of them I want to avoid verticals. I don't have code or covenant
restrictions, but I do have a wife.

3. Here's the physical situation: My suburban property has two houses
on it but no real trees I could use as anchor points. However, from
peak of the big house to that of the guest house I can get about 96
feet. The big-house peak is about 25 feet high and the guest house
about 13. For visual purposes, I'd like to use as thin a wire as
possible.

4. Here's my idea: an end-fed wire with traps for multi-band use. I
don't see how I could use a center-fed dipole unless the feeder came
back parallel (right next to) along one leg of the dipole. In other
words, I can't feed at perpendicularly. For a variety of reasons, the
azimuth of a wire line between the two houses would be about 25
degrees/205 degrees.

So . . . what do you think? What kind of performance do you think I
could expect from this setup?

Many thanks! ---Todd


Try an off-center fed dipole (OCF).

Here's what I use:
http://www.wcerc.org/Projects/ocf_dipole.asp

Here's the balun I use:
http://www.balundesigns.com/servlet/...4-cln-1/Detail

I am a QRP CW operator with no trees on my property. I run a Small
Wonder Lab SW-40 (1.5 watts) and a Yaesu FT-817 at 2.5 watts. The
balun is tied to a PVC vent pipe on my roof, about 25 feet in the air.
The long end of the antenna goes to my shed and terminates about 15
feet above ground. The short end runs to my garage and terminates
about 12 feet above ground.

The antenna loads on 80 but the bandwidth is very small. Works fine
on 40 -- with my QRP rigs, I work into Europe, S America, Caribbean,
Canada, all over US, occasionall into South Pacific.



Here is a commercially available OCF dipole:

http://hamcall.net/7bandocf.html

HF Antenna Options
 

On 8/6/2011 6:28 PM, Kickin' Ass and Takin' Names wrote:

4. Here's my idea: an end-fed wire with traps for multi-band use. I
don't see how I could use a center-fed dipole unless the feeder came
back parallel (right next to) along one leg of the dipole. In other
words, I can't feed at perpendicularly. For a variety of reasons, the
azimuth of a wire line between the two houses would be about 25
degrees/205 degrees.

So . . . what do you think? What kind of performance do you think I
could expect from this setup?

Many thanks! ---Todd


Try an off-center fed dipole (OCF).


I'm inclined toward OCF also. I ran one for a while, which worked out
well because I could run the feed down to the shack window right at the
short side of the thing. I'd suggest a tuner as well. They do tune okay,
but the tuner extends the useable frequencies. Also, my antenna was
marginal at 20 meters. OCF isn't the "ideal" antenna, but you could do a
lot worse.

- 73 de Mike N3LI -

HF Antenna Options
 

On Sun, 07 Aug 2011 19:43:12 -0400, Mike Coslo wrote:

On 8/6/2011 6:28 PM, Kickin' Ass and Takin' Names wrote:

4. Here's my idea: an end-fed wire with traps for multi-band use. I
don't see how I could use a center-fed dipole unless the feeder came
back parallel (right next to) along one leg of the dipole. In other
words, I can't feed at perpendicularly. For a variety of reasons, the
azimuth of a wire line between the two houses would be about 25
degrees/205 degrees.

So . . . what do you think? What kind of performance do you think I
could expect from this setup?

Many thanks! ---Todd


Try an off-center fed dipole (OCF).


I'm inclined toward OCF also. I ran one for a while, which worked out
well because I could run the feed down to the shack window right at the
short side of the thing. I'd suggest a tuner as well. They do tune okay,
but the tuner extends the useable frequencies. Also, my antenna was
marginal at 20 meters. OCF isn't the "ideal" antenna, but you could do a
lot worse.

- 73 de Mike N3LI -


Agreed. Forgot to mention that I use a tuner with mine.

I have an old ICOM IC-729 with the companion AT-150 tuner.