M107C vs. M108C

[Henry HPSD]

Hi Marconi,

Ah oke, got it.

No, you dont really need to verify "real world".
As long as you do things "rigth".

Modeling is more accurate that 99,9 percent of the "antenna guru's" can measure.

The debate wheter or not modeling is accurate is already done by guys with much more knowledge that us all combined.

It is not for nothing the US gouverment specificly asked if we were planning to use the software for nuclair purpose.
Another example is the CST seminar i went to a couple weeks ago..CST is used for example on rockets to see if the EM field has any influence.
You cant have any mistakes there.
So to get back at hydef his statement...well..it is kinda rocket science isnt it hihi

If you follow the "manual" the provided results within the limits provided are accurate as can be.

And yes, i do know each situation is different, houses...trees...etc.
But just think about all the antennas that go out the door here, all 50 ohms direct impedance...and no complaints only happy people.

Another example..the 5el U yagi i made this weekend.
The "damm' thing didnt show the SWR/return loss as expected.
I too was going..perhaps that tree..perhaps this perhaps that etc.
So, i re-measured the antenna inserted into the program and you probarbly know who was wrong hhihi

Kind regards,

H.

 

[radioreddz]

i know in looking at beam antenna designs it seems like the only manufactor's that got or get it right with boom length was hygain with the big gun quad and Mosley beam company. seems to me every other beam antenna manufactor has there boom lengths about 2' too short. in testing on a Maco Shooting Star we made the boom length to specs of a Mosley i belive power master beam which is 18' and saw an improvment on receive & transmit. i also knnow of a couple other guys that have extended the boom lengths a mear 2' on there Gizmotchy antennas and saw an improvement. i'm not going to get into Smeter readings but i know in the case with the Maco Shooting Star folks that we could just barely read there signal were brought up enough for ledgeable reading for a qso. and thats real world testing. i know of the same results guys have had just by moving the reflector element as far back and the first and second director acordingly on there 3 element maco comet and saw an increase in TX & RX.

 

[Henry HPSD]

Hello Radiorezz,

Hoping were not going to much away from the "thread"...

Im with you that some of the present day availible beam antenna's can be improved.

But perhaps not in a way you have your mind set on now.
One should be very carefull to just "add" length to a boom.
or to use other dimensions without changing the element diameter and length as well.
all three parameters have dramatical impact on the entire antenna.

But i do understand your "feeling".
It is possible that you have had that experience of "improvement".
Rembering a gizmotchy thread here on this forum where almost any change would have done good hihi.. so in that case yes.
(not to hit on gizmotchy, im sure they have come a long way since then)

But Im also quite confident that with most present day Yagi's the changes that that will happen again are neglible.
Just to name a couple "others"..array solutions, M2,force 12 etc etc etc

Kind regards,

H.

 

[Rooster 903]

I am getting ready to put up a m108 with the 3" 40 Ft boom minus 1 element effectively making it a m107 on a 40 ft boom. I noticed that the modeling was done on a 36' boom? Has anyone modeled and optimized that spacing of 7 elements on 40' boom?

Thanks

 

[Henry HPSD]

http://cb-antennas.com/?page_id=432

Kind regards,

Henry 19sd348

 

[Rooster 903]

Very cool, thank you so much for taking the time to send me the link.

Thanks

 

[Shadetree Mechanic]

I was looking for some info on the Maco 105C and found this interesting thread. Bump!

 

[Marconi]

Hey STM, check out Henry's Website here is the link: M107C vs. M108C

He has, among others, several Maco beam models. and some with dimensions.

 

[Rangerman68]

The cb-antennas site is down. Did any of you guys happen to save those specs? Wanting to get the most gain I can out of 7 elements. I heard of some guys running 48ft booms with those.