omni ground elements effecting a beam below them

[AudioShockwav]

I see that. That extra below the coil and feed point is for mast attachment?

That coil is a choke made from coax, and it extends up into the antenna.
The actual feed point is about half way up the antenna and uses a shorted impedance matching stub inside the fiberglass, and a capacitor to couple the top section.
That's why they call it a center feed antenna.
It doesn't need radials because both sides of the antenna are already there.
This is much different from the matching on the bottom of the imax antenna.
Sirio is more realistic about there gain figures than Solarcon ever was about the 99 and the imax with 9 and 12 db gain.

73
Jeff

 

[Marconi]

I would install mine about 3 feet above the Mosley TA-33 WARC yagi.

Bump

 

[Alabama Buckeye]

That coil is a choke made from coax, and it extends up into the antenna.
The actual feed point is about half way up the antenna and uses a shorted impedance matching stub inside the fiberglass, and a capacitor to couple the top section.
That's why they call it a center feed antenna.
It doesn't need radials because both sides of the antenna are already there.
This is much different from the matching on the bottom of the imax antenna.
Sirio is more realistic about there gain figures than Solarcon ever was about the 99 and the imax with 9 and 12 db gain.

73
Jeff

Thank you for that explanation of the "center fed" nature of the GM. I failed to see that, thanks Marconi for your input on this fact, skimmed right over it; my bad.
I'm going to read more into how a apparent monopole is actually a dipole in disguise. Learning more every day.

 

[Marconi]

I would install mine about 3 feet above the Mosley TA-33 WARC yagi.

The one on the picture, I think is is too close to the beam. Will there be any difference if I install it close to the beam against 3 or more above any yagi antenna ?

Hey Alexis, have you had a chance to check and see if your new Gain Master will work above your beam.

I'm feeling better now, so I think I have a model of a 3 element Maco yagi with a good match...that hopefully is close to specs.

I think a 3 element yagi will do the job of either showing, OK or Bad effects, with a close to specs Gain Master installed above.

 

[Marconi]

I'm going to read more into how a apparent monopole is actually a dipole in disguise. Learning more every day.

AB, you might have some luck reading over the GM Manual. I don't think the subject of Common Mode Currents has come up in this discussion about the GM, but this type of antenna current is used as the major feature in the design.

Here is a good YT video that shows a step by step rebuild of the GM that might be of help.

Rebuild the Gain Master - by Mike

Good luck,

Marconi

 

[Marconi]

Here are two Eznec models that are pretty much to scale.
1. Gain Master is active.
2, 3 Element yagi is active.

Both models combined show to be skewed a little bit, based on the individual models alone that I added together per the question Alexis asked (not included).

I was surprised at the good results, when compared with my personal experiences with my GM low to the ground some years ago.

I thank Henry for his comments some time back as well. I always believed...two heads are better than one.

If you have questions, just ask away.

Thanks,

Marconi 390

 

[Alabama Buckeye]

two Eznec models
1. Gain Master is active.
2, 3 Element yagi is active.

...surprised at the good results, when compared with my personal experiences with my GM low to the ground some years ago.

Marconi 390

edited for brevity
The YouTube making of GM was quite informative. Have to ask about the push-up pole? Brand and Height?
Eznec modeling also quite informative! Low 8D horizon elevation quite impressive. That's what I'd love to see with my set up. Can only hope.

I'm leaning strongly toward the GM; though I'm reluctant to set aside my Imax 2000.

Thanks for your time, Cheers. Next round of Stout on me.

 

[Marconi]

Have to ask about the push-up pole? Brand and Height?

Type DX Commander into the YouTube Channel Search. Or:

---

https://www.youtube.com/results?search_query=dx+commander

 

[Alexis Mercado]

Thanks Marconi. I haven’t installed the 5/8 Gain Master above the yagi. As soon as I do it, I’ll let you know.

 

[Marconi]

Thanks Marconi. I haven’t installed the 5/8 Gain Master above the yagi. As soon as I do it, I’ll let you know.

Thanks for the update.

BTW, I set the GM 36" inches above the Maco 103. I see little difference overall, so my idea that the combination might be a bad idea was likely wrong. I don't see enough difference that you can tell, just working your radio.

Let me know what you find out in the real world, OK?

 

[Alabama Buckeye]

Type DX Commander into the YouTube Channel Search. Or:

---

https://www.youtube.com/results?search_query=dx+commander

Very Much appreciate link. Quite informative. Will pay attention to more. 2nd round of Stout on me, as well.

Just what I need to push-up an I-Vee.