| Author |
Message |
    
Ajm1571
Intermediate Member
Username: Ajm1571
Post Number: 112
Registered: 12-2004
| | Posted on Thursday, September 15, 2005 - 1:01 pm: | 
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I just put up a set of 103's an they are only 20 ft off the ground. everybody I talk to say they are working fine but the question I have is this.
My father in law lives 15 miles north of me an I have the beams turned north an south he fades out of my receive quite a bit an he says i drop down in his receive. Now I know thats what they are supposed to do that amn they are working but when I flip my switch on my radio he says i only drop maybe 1 s-unit in his receive. He said there really is no difference between my a99 an beams when i have my switch flipped. Thats what I am confused about becasue technacilly I should still not be doin that good off the backside of the beams. Maybe I am wrong but I just cant figure it out. I hoping to get them up at 35-40 ft here in the near future. Also I live in a mobile home an do I dare put em up right beside it or away from it? Dont know if all the aluminum from the trailer will effect performance. Any insite would greatly be appreciated  .
Allen CEF565 |
Tech808
Moderator
Username: Tech808
Post Number: 7156
Registered: 8-2002
| | Posted on Thursday, September 15, 2005 - 1:19 pm: |
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Ajm1571,
This is NORMAL with Beams.
Many times when I have someone less than 75 100 miles I will Pick them up Better and tlak to them easier with the BACK of the Beams to them.
This has also worked with contacts well over 1000 miles due to conditions on the CEF Nets.
I can have them pointed at FL and that is the Only way I can talk with Moderator136 in Iowa.
When I try for Tech291 in OH. I HAVE to turn the beams to CA to get him off the back side and he can hear me great on the LONG PATH.
You will find many times with Beams you will OVER SHOOT the person you want to talk with and will need to turn them 180 away using the (Long Path) to reach them.
And with this Sunspot Cycle getting close to hittim bottom the IMAX has been working as well as the beams.
Hope this helps,
Lon
Tech808
CEF808
N9OSN
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Ajm1571
Intermediate Member
Username: Ajm1571
Post Number: 114
Registered: 12-2004
| | Posted on Thursday, September 15, 2005 - 10:55 pm: |
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Thanks Lon! That really did help. Now I wont be confusterated anymore .
Allen CEF565 |
Airplane1
Advanced Member
Username: Airplane1
Post Number: 568
Registered: 5-2004
| | Posted on Friday, September 16, 2005 - 7:07 am: |
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What does long path mean?
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Tech808
Moderator
Username: Tech808
Post Number: 7171
Registered: 8-2002
| | Posted on Friday, September 16, 2005 - 7:39 am: |
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Airplane1,
SHORT PATH = From me here in IL with my Beams / Signal pointed EAST DIRECTLY at you in PA.
LONG PATH = From me here in IL with my Beams / Signal pointed WEST away from you in PA where my signal travels around the world to get to you.
Lon
Tech808
CEF808
N9OSN |
Ajm1571
Intermediate Member
Username: Ajm1571
Post Number: 116
Registered: 12-2004
| | Posted on Saturday, September 17, 2005 - 3:31 pm: |
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Hey Lon, I was told I can lean my elements 30 degrees an I would be able to get both vert an horiz on my beams. Is this a good idea? Any advice would greatly be appreciated .
Allen CEF565 |
Tech808
Moderator
Username: Tech808
Post Number: 7214
Registered: 8-2002
| | Posted on Saturday, September 17, 2005 - 3:42 pm: |
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Ajm1571,
Sorry I have never tried it or know of anyone who has so I cannot say.
Sounds like a good Question for Tech833.
Lon
Tech808
CEF808
N9OSN
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Starface
Intermediate Member
Username: Starface
Post Number: 194
Registered: 1-2005
| | Posted on Saturday, September 17, 2005 - 9:37 pm: |
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I had a friend try that with is 103 and it broke down the signal on both V and H ... but was great with other stations that had their beams set the same way.... So I'm guess thats why there are two side to beams
Till next time
Starface CEF#476
Southeast Net Control
Auburndale,FL |
Kb9umt_don_123
Member
Username: Kb9umt_don_123
Post Number: 55
Registered: 3-2004
| | Posted on Thursday, September 22, 2005 - 11:05 pm: |
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Allen CEF565,
I would like to comment on a couple things. First if you are only 20ft off the ground (I will assume you mean you are 20ft to the boom of your 3 element beam) then approximately 9ft of the bottom elements are toward the ground which puts your at about 11 ft to the elements tips of the beam...that is not high enough. You should try to get the antenna one wavelength in height, that is about 36 ft for CB/11 meter band. Why? Because you are fighting ground effects, your antenna pattern will not be normal, your SWR is affected by this also and the antenna surroundings will cause effects..like metal objects, trees, other buildings etc...you also are and will cause more RFI/TVI being closer to the ground.
Your father-in-law at 15 miles away will see little difference with your beam is so low to ground. Your beam seems to have a pattern but it might not be normal with your surroundings effecting the pattern and gain. What should be normal is from 20 to 25 db back rejection which is about 4 s units or so decrease when turned away..so a properly set s-meter in this example a s9 signal should be decreased to s5 or so when the beam is turned away and the reflector is then toward your father-in-law...the less signal or of far out a station the more you will see this decline..also remember that many beam antennas have a lobe pattern that would not necessary have the complete opposite (or backside) be the lowest rejection signal but maybe the sides or even at or around the 60deg mark.
I have to say that I have had many yagi/beams and it is NOT normal to have the same forward signal as the back or rejected side signal..NOT normal. Again at low height your antenna can and will NOT have proper pattern or can be blocked or bouncing from surrounding objects (I have also had folks seen folks not put the elements in proper order on the boom...longest to shortest...shortest points to where the gain will go toward and longest points to where the signal will be rejected from). Lon's response is different than mine so I want to point out a few things there also. I have never had a ground wave signal some 70 to 100 miles out and had a better signal pointed the other direction with my yagi/beam, that would indicate that my beam is not working properly....well that is ground wave but other propagation then yes I have... when working the northern lights, backscatter, or aurora this could happen but it's not the norm...under normal conditions local ground wave (local ground wave being from 0 to 200 miles out) a properly working antenna under normal ground wave propagation conditions should have increase of signal pointed at the station and a reduced signal pointed away from the station or signal wanted. Long Path and Short Path....I think a google search on "Propagation" would be some good reading for some of what is being talked about here. There is no doubt in my mind that you are NOT using Long Path going from point A to point B if point be is a few hundred miles out...you might be using backscatter from the skip conditions but not Long Path. Those of us more northern will and can work aurora or the northern lights were you will have to pointing north WILL have an increase on signals just about any direction to other northerly stations no matter East, West, or South...but you will be bouncing off the Northern effects.
As far as putting your M103 3 element beam at a 30d or 45degree angle you will be decreasing your signal on BOTH vertical AND horizontal...so you will decrease your signal to BOTH folks on vertical and horizontal by about 6 to 9db. This might help in some DX type conditions were the signals are bouncing/skipping between vertical and horizontal polarization but I would suggest that putting it either 100% vertical or 100% horizontal would be directing 100% of your signal in the polarization you would like and actually show an increase instead of a decrease in both.
Hope some of this helps...bottom line is to get your antenna up higher and for those really interested in reading up on what or how signals skip/bounce around trying reading on different types of propagation and you will then know really what is going on with your signal and why.
de kb9umt Don/123
http://www.HamRadioHelp.com
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