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CAN'T WORK EM IF YOU CAN'T HEAR EM !

Sep 8th 2011, 11:11

N8CHR

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
I have a Dipole up North -South at 45 feet, inverted V at 40 feet and a vertical with radial, ground mounted. I'm in a sort of valley with 60+ feet high trees all around. Tower and beam are out of the question. Rig is Kenwood TS 450AT. I'm in Ohio close to the West Virginia border. Can't hear Europe. Hear the west coast working them but can't hear Europe. Can hear and have worked Australia with good reports and into South America.
Anyone have any ideas how I can increase my receiver gain so I can at least hear more of Europe? Would adding an external receiver pre amp or something else help?
Thanks
Tom N8CHR
Sep 8th 2011, 12:04

W1RFIAdmin

Joined: Jul 25th 2011, 14:25
Total Topics: 0
Total Posts: 0
Hi, Tom,

A preamp won't help, based on the antenna you described. The should pick up all of of the signal (and noise) that is present in your location.

I would expect that you should be hearing Europe at least some of the time. A dipole or inverted vee will have maximum radiation broadside (right angle) to the antenna, and minimum off the ends, although an inverted vee will have more radiation off the end than a dipole, as a rule.

Looking at a great-circle map, although you would hear minimum signals from far eastern Europe, you should have reasonable propagation to western and souther Europe from the inverted vee.

The vertical should hear equally in all directions. It may or may not be efficient on transmit, but on receive, it should pick up well, with the limiting factor being the signal to noise ratio at the antenna, which will not be improved by adding a preamp or increasing the efficiency of the antenna.

The inverted vee should be high enough to hear DX on 20 meters and above, and do a fair job on 40 meters, although a bit more height would be better. Being in a valley, you will have a lower limit on the angle of radiation that you can hear well, but what this will generally mean is that the band will not be "open" to you as early as it would be for someone who did not have the the low angles blocked by the hills, but as the band opens, especially on 20 meters and below, the usable angles at which the DX signals arrive at your location are usually a bit higher. If you have a 30 degree slope to the hills in the direction of Europe, that would really cut down on the signals you will hear in that direction, but if the angles to the hills are similar in all directions, that is not your limting factor.

You didn't mention at what times of day and frequencies you are listening for Europe. At this period of low sunspot activity, 20 meters will be primarily a daytime band, open to Europe starting early in the AM and continuing all day. At night, you will be open on 20 meters to South America nicely and to the west more than the east, just as you have experienced.

What I suggest that you first do is to give a listen at various times over one of the major DX contest weekends. You should have hundreds (literally!) of DX stations you can work. With your modest antenna, especially at 100 watts, you'll be beaten out in the pileups, but especially Sunday afternoon, many stations are begging for contacts, so you should be able to put a lot of new ones in the log.

You can also, if you want to get industrious, use one of the propagation modeling software packages to predict what the bands will look like and in what direction and times, from your exact location.

I use the ITSHFBE suite of programs, available for free from the US ITS in Boulder, CO. See:

http://elbert.its.bldrdoc.gov/pc_hf/hfwin32.html

It's a bit cumbersome to learn, but I figured it out farily easily and it does some really cool things with propagation, graphs, coverage maps, etc.

73,
Ed Hare, W1RFI
ARRL Lab
Technical forums moderator


Sep 8th 2011, 13:11

W1VT

Joined: Apr 4th 1998, 00:00
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Total Posts: 0

A cumbersome but effective way of getting around hills is to find a better location and operate portable.

Zack Lau W1VT
ARRL Senior Laboratory Engineer
Sep 9th 2011, 04:34

KM3F

Joined: Mar 6th 2008, 13:50
Total Topics: 0
Total Posts: 0
Hello Tom,
What bands are you interested in for Eurpean DX?
Here is what you would need to pay attention to.
On 75, you won't hear any above 3.8 as a general rule because they hafe no allocation above 3.8.
On 40 there is European DX to be heard but often below 7.175.
In the early morning 40 will often support ZL and VK contacts.
On 20, it's whenever propagation will allow it.
Here on the eastern border of PA. with a dipole that should not work as well as it does, I can work all over Europe in the late evening and early morning hours as well as on 40 meters to the same areas.
It takes a good antenna setup, using all the radio's filtering help you can dial in and patience hunting the hard to accomplish contacts and timing the calls.
I hear stations in your area making the same contacts but not quite as often.
Good luck.
Sep 9th 2011, 10:12

N8CHR

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Thanks for the replies.
I work from home 3 days a week so I can take care of my wife. I came across one of the DX nets in the morning on 20 meters. The Southern Cross Net on 14.2385 at 1230 hours. I can hear a lot of state side stations calling and hear some of the european station but not many. I hear and have worked into VK land. I can barely hear net control. I hate to give out my call to net control if I'm un sure if he hears me. I think thats my biggest concern. I'm planning on working the European Contest this weekend That should tell me what I need to know. Thanks again
Tom N8CHR

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