• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.

The difference an antenna makes on HF

Moleculo

Ham Radio Nerd
Apr 14, 2002
9,068
1,399
283
I dialed around the 15 meter band today and heard several weak stations working the band. I decided to give it a try with both my Cushcraft R6000 6m-20m vertical and my multi-band inverted V dipole, both with the feed point at 40 feet. After calling CQ for a bit using 1KW with no luck, I spun the dial and found another local, W6TA also working 15 meters. The difference? He was actually working 15 meters into Europe from L.A., while I was not. I couldn't even hear the stations he was easily working. The antenna he was using: A 40-10 meters log periodic at 110 feet:

DSC_0052.jpg



He's got a real nice station, check out more pics at: Pictures by W6TA - Photobucket

It sure makes a difference to have a great antenna (y)
 

Savoir Faire

Member
Jul 16, 2010
16
0
11
Antenna nice BUT...

The height of the antenna is the real kicker...

You can conceivably go too high but two wavelengths is an awesome height and makes the gain of the antenna even higher.

73 and good dx,


N4SLR
 

K8PG

The Outer Limits
Jul 7, 2006
201
2
28
Chatham MI. EN66mi
Difference the antenna makes.

I say that is a Kick Ass antenna system and station,
The higher the better-Never heard of TOO High ? for HF.
The key and heart of any station is the antenna system
with hight-2-7 wavelengths I would say.The Dx is there
most of the time you just need the antenna to hear them
if the propagation is right.

Paul-K8PG- CW IS AMATEUR RADIO
 

Captain Kilowatt

Professional Amateur
Staff member
Apr 6, 2005
16,992
11,420
823
59
Nova Scotia,Canada
I agree,you can never get an HF antenna too high except in very particular and specific circumstances. It may be possible to be so high that the antenna develops a very low TOA that may not be conducive to working a certain station at some time that happens to be in a certain geographic area that due to propagation requires a higher TOA at the time but in about 99% of DX contacts you can never be too high. Generally with a large yagi you will have enough gain at any angle to make the contact.
 

VA3ES

Old Buzzard
Oct 30, 2010
645
80
38
Ottawa, Ontario
A multi-element yagi or log periodic will exhibit more gain than any vertical or dipole. For a vertical to work well on HF, it needs a counterpoise system, (radials). Elevated verticals also need radials, but not quite as many,. Many multi-band dipoles are extremely poor performers on the higher HF bands.

The only multi-band dipole that works well on 15, is a 40M doublet. The problem with multiband dipoles that are long (such as an 80M dipole fed with 450 ohm line) is that at the higher HF frequencies it starts to exhibit too many vertical lobes which are useless and waste power. Any gain that is derived is going up, not out to the horizon. Too high a TOA.

Yagis exhibit directional gains of 6dBd or more, while any dipole or vertical is 0 dBd.
 

Moleculo

Ham Radio Nerd
Apr 14, 2002
9,068
1,399
283
I should note that my multi-band dipole is really more like a fan dipole - It's the Alpha Delta DX-CC which has full size elements on 10, 20, 40, and a loaded 80 meter segment. One day I might be lucky enough to live where I can put up a real tower, lol.
 

northern35s

Active Member
Jan 24, 2011
223
42
38
Yagis exhibit directional gains of 6dBd or more, while any dipole or vertical is 0 dBd.

I guess you're right, in that a dipole will never have gain over a dipole, just as a three element yagi will never have gain over the same three element yagi ;) however a dipole does exhibit gain in the order of 8dBi at just over a half wavelength high, it will also exhibit very low angle radiation when a few wavelength high eg 10m dipole at 30m will have multi lobes with the lowest at approximately 4.5 degrees and a very respectable 6.4 degrees a 20m also a DX worthy 11.3 degrees at 10m, a beam it will never be though :D
 

W5LZ

Crotchety Old Bastard
Apr 8, 2005
6,832
888
173
Oklahoma
Isotropic antennas or gain figures can be very misleading. I've found that taking those figures with a large dose of salt is a very good idea. It also helps to keep in mind that those isotropic antennas are being compared to 'perfect' antennas located in a 'perfect' position. It's still a comparison to a 1/2 wave length antenna, so how can they have 'gain' over themselves? Keep things in perspective...
- 'Doc
 

Beetle

Sr. Member
Dec 7, 2005
3,082
1,172
173
78
Western Washington
Studies have shown that most stations that regularly establish contact with other stations in the local area or halfway around the world DO use antennas. That seems like a recommendation. You should use one! :whistle:
 
  • Like
Reactions: 2 people

dxChat
Help Users
  • No one is chatting at the moment.
  • @ BJ radionut:
    I hope he did not ask that question on the "ZED" he would get vaporized...75% telling in some "polite way" are you going to put up a "REAL" antenna? The rest telling him that's the greatest antenna ever with my 7300o_O:coffee:
  • @ Roadstar:
    still the dx wa 135 antenna
  • @ cbjunkie:
    test
  • @ cbjunkie:
    the guy qrming 27385l is on 27383 is Matt K2YCK in New York for info very bad operator causing intententional
  • @ cbjunkie:
    bleedover to 27385lsb