| Author |
Message |
    
Bburck
New member
Username: Bburck
Post Number: 3
Registered: 1-2005
| | Posted on Thursday, January 27, 2005 - 7:35 am: | 
|
OK, here is my question: A friend and I were discussing the possibility of a 10 element beam. Judging by the work instructions/schematic for the Maco M108, where the 4,5, and 6th director are all the same length and space apart, would it be theoretically possible to just add 2 more elements the same length and space apart to the 8 to create a 10 element beam??? What does everyone think of that? I have owned all kinds of beams, my first was a PDL2, next MoonRaker4, then the Super Lazer 400, then I put of the M105 and stuck with that. I have to say the Moonraker4 was comparable to the 105, but I liked the simplicity of the Flat5. My next set of beams will probably be the 108s on the flatside, but, if there is any real benifit to adding more elements, maybe a 10 element!! |
Kj7gs
Junior Member
Username: Kj7gs
Post Number: 10
Registered: 12-2004
| | Posted on Thursday, January 27, 2005 - 5:36 pm: |
|
I think the number of elements has a "cost effectiveness" to it, where you really don't get much enhancement past a certain point. Have you considered stacked parasitics? Bear in mind that your pattern will be extraordinarily sharp, which can be a good or a bad thing! |
Bburck
New member
Username: Bburck
Post Number: 5
Registered: 1-2005
| | Posted on Friday, January 28, 2005 - 7:29 am: |
|
Kj7gs, thanks for your imput. I do have some questions, though. I understand how and what it does, but as far as cost effectiveness goes, which two stacked antennas would be comparible to say just the 8 element yagi? OH, yeah, of course these are for 11 meter. Maybe im not exactly sure of what you are trying to say. Stacked 8s would cost a fortune, not only that, just the fact that the wind load would be astronomical. Would stacked 6 elements, or even 5 elements have comparible DBgain? and cost effectiveness asside, back to the original question, do you know if it is theoretically possible to add the two extra directors on an 8 element yagi, keeping the same dimensions as directors 4,5,6? Thanks again!!
|
Tech833
Moderator
Username: Tech833
Post Number: 973
Registered: 8-2002
| | Posted on Friday, January 28, 2005 - 6:00 pm: |
|
Stacking beams adds 3 dB gain over whatever they were singularly. This assumes proper phasing and spacing of course!
An 8 element yagi with stahdard element spacing will have the same gain as a pair of 5 element beams, but not nearly the rejection of the phased array. |
Ferd1605
New member
Username: Ferd1605
Post Number: 9
Registered: 1-2005
| | Posted on Tuesday, February 01, 2005 - 4:59 am: |
|
persoally , i would look up the specs. for the Hygain longjon 5 element beams , build 2 and stack them . If my memory is still working hight , the longjohns were besighend for over all gain , not so much for front to back . I think it is easer to stack 2 beams to get the 3db than to stretch the boom . besides , to get max gain , element lengths and spacing needs to be redone ... GOT-ER-THUNKED-ABOUT ... |
Wayne
Junior Member
Username: Wayne
Post Number: 31
Registered: 12-2001
| | Posted on Monday, May 30, 2005 - 9:19 am: |
|
I use to run a Long John now I run a 12 element lazer which is six elements on the flat side with a 31 ft. boom, so you say if I would stack the long john I would get more db gain than the Lazer on the flat side |
|
