M107C vs. M108C

[Marconi]

Anybody interested in these scaled models for either of these two antennas. They were constructed as per the Charles Electronics Manuals, currently posted on the Maco Website.

Out of convenience in modeling I did not include the boom or the mast, but neither addition made a significant difference. Reason is my software is limited to 500 segments and I maximized the segments to the limit instead or waisting the needed segments on the long boom and the mast.

View attachment M107C vs. M108C.pdf

 

[Henry HPSD]

Hello Marconi,

It seems you have uploaded the "view antenna" plots
though the "interesting informtion" ..is missing.
wonder if im correct though...as im the only complaining after so many views hihi.

Anyway, not sure if im gonna reply on that other forum.
I tend to drift a bit away from the forums, a lot of forums end up in either yes/no debate or the often seen "i have 30 years experience so i know all". (expect wwrf of course hihi)
Sadly there are only few "members" who actually provide some facts.

It is much easier though, just to "shout" something (foolish), especially if one can make another look bad. Probarbly some compensation thing going on hihi.

well..we'll see its not in a hurry lol.

Take care!

H.

 

[Marconi]

Thanks Henry, I agree.

 

[Shockwave]

Field plots are missing.

 

[Marconi]

Field plots are missing.

Henry mentioned this all started on another forum. I posted some claims about my personal results over there, regarding my beams over the years, and then posted the antenna view of the models...the results for which, more or less, supports my thinking on these two in particular.

I just posted the antenna view over there, and I used the same file to post here.

Here is part of the results:

View attachment M207c vs. M108c per specs..pdf

 

[Henry HPSD]

Hello Marconi,

Could you be so kind and plot the freespace elevation and azimuth patterns preferbly with the average gain figure ? Im guessing for "fair" comparisment most of the antenna users are interested in those ?

Kind regards,

H.

 

[Marconi]

Hello Marconi,

Could you be so kind and plot the freespace elevation and azimuth patterns preferbly with the average gain figure ? Im guessing for "fair" comparisment most of the antenna users are interested in those ?

Kind regards,

H.

Henry, is there a report that prints the average gain value? I've just been making a note on the antenna view.

View attachment Free Space and AG.pdf

 

[BlackSkillet]

Is the Maco M107 a Better antenna

I am looking at the results and from what i see it seems like the Maco M107 IS BETTER ANTENNA but i also believe the Maco M105 is a DX monster

 

[Marconi]

I am looking at the results and from what i see it seems like the Maco M107 IS BETTER ANTENNA but i also believe the Maco M105 is a DX monster

BS, here is a model of the Maco 105C with current manual dimensions to specs.

I also modified this model and call it the Marconi 105C. It uses a 4' foot longer boom. I changed the spacing distribution and made some minor adjustments to some of the element lengths as noted.

Note the improvement in gain and rejection. I tried to extend the bandwidth, but it doesn't look much wider. The curve is much improve however, and I consider that an advantage. I also see a very irregular curve on all these other Maco models with a dip...higher in frequency.

View attachment Maco M105C vs. Marconi 105C.pdf

 

[HomerBB]

The 107 is better than the 108.

The Marconi is better than the 105.

Cool

 

[Henry HPSD]

Hi Marconi,

No, im not aware of a "insert" average gain function...that would be a nice asset.
The only way now is to use the 3d freespace plot.
And well, it needs to be done in a 3d freespace plot other wise it cant calculate the "entire" power of course.
but it would be nice if you could insert that figure in a azimuth or elevation plot.
Ill aks roy if such is possible in a update, thinking about it perhaps efficiency is not a bad extra as well.

If possible marconi could you be so kind to (always) add the free space azimuth and elevation plots, those are valuable for comparisment.

Keep up the good work !

H.

 

[Marconi]

Thanks Henry, you've requested this info before. I keep forgetting. I'll check out the 3d free space plot thing too.

Edit: I don't know about the 3d function Henry. When I checked I only found something about 2d settings in the Antenna View topic entitled View/Object. Give me the rundown on the use of 3D, how and where.

All these models shows Average Gain of 1.000 = 0.00db, and in the Sources function I use SI as the Type.

 

[Marconi]

The 107 is better than the 108.

The Marconi is better than the 105.

Cool

You may be right Homer, but IMO it's hard to tell if we can't duplicate what a model might predict, and for sure that applies to the complications of a multi-element beam.

Remember what Master Chief use to preach to us about antennas, "...just about anything will work."

I guess that leaves us to ask or wonder, "...so I ask how well?"

 

[Henry HPSD]

Hello Marconi,

The average gain factor is a relation between the "power" in the far field and the amount of power which we have selected to go into the antenna.

Now..if that figure is "one" all is transmitted by the antenna and the model can be seen as accurate.

The ONLY way to generate this figure is to run a "freespace" (plot type =) and 3D version.
all other options will generate valse figures !!!!
As in that case the computer "calculates" the entire antenna pattern, and not just a "slide" as in the elevation or azimuth plot.
Thats also the reason for very large antennas and small computers the calcualtion time will slightly rise.


Well back to work now..(wife's not so happy since it is sunday)
But have to send 1 moxon, 1 5el U-yagi, 2 x4el FMR-Yagi and a 3el FMR-Yagi out the door.
And time (as always hihi) is limited.

If i may ask...
What did you mean with "but IMO it's hard to tell if we can't duplicate what a model might predict" ?

Enjoy the sunday !

Kind regards,

H.

 

[Marconi]

Hello Marconi,

The average gain factor is a relation between the "power" in the far field and the amount of power which we have selected to go into the antenna.

Now..if that figure is "one" all is transmitted by the antenna and the model can be seen as accurate.

The ONLY way to generate this figure is to run a "freespace" (plot type =) and 3D version.
all other options will generate valse figures !!!!
As in that case the computer "calculates" the entire antenna pattern, and not just a "slide" as in the elevation or azimuth plot.
Thats also the reason for very large antennas and small computers the calcualtion time will slightly rise.


Well back to work now..(wife's not so happy since it is sunday)
But have to send 1 moxon, 1 5el U-yagi, 2 x4el FMR-Yagi and a 3el FMR-Yagi out the door.
And time (as always hihi) is limited.

If i may ask...
What did you mean with "but IMO it's hard to tell if we can't duplicate what a model might predict" ?

Enjoy the sunday !

Kind regards,

H.

I must have been half asleep Henry. I set the wire loss = O, the ground = free space, and the plot type = 3D.

I re-read the 8 part instructions for Average Gain on page 70, and I noted it said to set ground = perfect not free space. I fixed this and it did change the AG a little bit.


I also was reminded that for accuracy, the model can only have one source and I was using the split function and that is undoubtedly considered by Eznec as two sources, albeit only shows 1 source in the Main View.


So when I fixed these in the model it shows AG = 1.022 = .10dbi instead of (1).


Thanks for your help.


Re: my comment, "but IMO it's hard to tell if we can't duplicate what a model might predict.”

I think based on the models I posted, Homer said that the M107C was better than the M108C. I was just suggesting that model results need to be verified by real world testing to see if we can duplicate those results…before we make our determinations.

I agree however, that the results do look a little like he said.