omni ground elements effecting a beam below them

[Alabama Buckeye]

Hey Homer,

Sorry to rejuvenate such an old thread, but I have a 2016 as well which is less than 1 year old and I would love to add a beam to my set-up but I have nowhere else to mount it as my 2016 is taking up my only location available. I don't want to remove it since it's still new and shiny, and works very well. Did your set-up seem to work ok for you with minimal re-tuning? I'd like a beam for better DX'ing and working 10 meter once I get my Tech license later this year, but is there any advantage to utilizing both (at separate times of course) or should I just switch to a beam? I only have a 10' mast mounted to the gable eave of my house so I'd have to keep the beam fairly close to the roofline and put the Sirio as high on the mast as possible to maximize the distance between the two. Am I wasting my time, or do you think I should be able to make it work. I mostly use 11 meter, but I'd like to work 10 as well once I get my license. I DO plan on getting an ATU to help, but am I going overboard here? Should I just take the 2016 down and put it away in the attic or garage for a day when my beam gets taken out by a tree limb or bad storm? I've never used a beam so I'm not sure what functionality I'll lose if I ditch the Sirio.

Thanks for everyone who commented on this thread, it's been helpful.

73 from 106 Central Massachusetts, I'm back in my corner...

I too am new, not to radio but to this site. Here's my answer on the principal question. Go For It! The beam is directional and becoming more so with each additional director. You miss the traffic in the direction the beam is not pointing.
Had great doubt about the matter until this marvelous volume of Positives came about.
My 5/8λ omni-directional has very good DX receive. Sometimes better one direction more so than another depending on conditions. My Yagi can then be rotated towards the greater or the faint signals for my rag chewing pleasures.

 

[Alabama Buckeye]

So...the 2016 radials are much shorter (30"?) and more of them to make up the area difference for a ground plane. Being as they're not extending out as far, they "shouldn't" cause as much of a disruption to the pattern of the beam as they're extended much less off the central point, at the mount. With the 72" and 102" radials those would extend much further into the pattern of the beam thus causing more issues yes? Also the father away I keep them (height wise), the less they should interfere?

The Imax GPK is not integral. I wouldn't mount the antenna with the GPK. I'll experiment with a 1/4λ with the long legged GPK under it.

The 30" radials on the 2016 are removable. Your beam will also serve as the ground plane.

 

[MeatMan]

The Imax GPK is not integral. I wouldn't mount the antenna with the GPK. I'll experiment with a 1/4λ with the long legged GPK under it.

The 30" radials on the 2016 are removable. Your beam will also serve as the ground plane.

Sounds like I need to save up for a new antenna/experiment hahaha. Antenna, rotor, cable... that's $500 easy (little budget)

 

[Alexis Mercado]

Hi guys. How about a Sirio 5/8 wave Gainmaster on top of a yagi? In my case, I have a Mosley TA-33 WARC antenna. Right now, there is a Sirio 827 antenna on top of the yagi, but, since a bird came to rest on top, lowered the tip and know it is resonant around 30 MHz, I plan to take the 827 antenna out and replace it with a 5/8 Sirio Gainmaster antenna.

Has anyone done this, GM on top of a yagi ?

 

[Alabama Buckeye]

In summary I gather from all that has been said, it'll doable.
Get the monopole as close to the Yagi as possible whether that be with 30" horizontal radials as with the 2016 or other similar monopoles. But I don't want diagonal radials extending downward through the horizontal plane of the beam antenna. Omit the GPK, with 103" diagonal whips.
***End Summary***
I'm still curious as to the radiation patterns; how does the monopole affect the beam pattern? I didn't see a previous example.

The Sirio SY-3 has quite a short boom. 4'7" from Driven to Reflector and only 7" longer than Driven to Director. Ant. weight is about 10# + 5# rotor. The. Imax 2000 is said to be 6# for a wag combined weight of 21# above the last guy wire support, 6' below, and only 16# 3' above the rotor. Total mast height 36'.

It's not a beefy rotor. RCA VH226F. I read absolutely nothing in the User Manual on antenna weight limits. The Imax 2000 (6#) is not expected to add a significant load on the rotor function, aside from wind load. Comments?

 

[Marconi]

Has anyone done this, GM on top of a yagi ?

Alexis the answer is...it is probably not a good idea to install a GM right above a horizontal beam.

If you read the Gain-Master manual, you will find two situations with specific warnings, instructions for height above a roof or other metal objects close by.

Marconi

 

[Alabama Buckeye]

Hi guys. How about a Sirio 5/8 wave Gainmaster on top of a yagi? In my case, I have a Mosley TA-33 WARC antenna. Right now, there is a Sirio 827 antenna on top of the yagi, but, I plan to take the 827 antenna out and replace it with a 5/8 Sirio Gainmaster antenna.

Has anyone done this, GM on top of a yagi ?

That would certainly meet all I've gathered from this thread. I might add, 25.5-30 mHz "no tuning required" description means what; not tunable?

Do check out Solarcon Imax 2000. Another fiberglass 5/8 that is Tuneable. I see em as low as $120 http://www.radioproshop.com/solarcon/max2000.htm, but that may be history, and as high as $289, Amazon. Cheapham.com $250. Shipping is horrendous, due to length.

"since a bird came to rest on top, lowered the tip and know it is resonant around 30 MHz,..." I'm trying to imagine this.

Marconi, I understand you're remarking on the antenna manual. Lord only knows their meanings. Such as don't have a ground plane as some very similar antenna do? Or avoid blocking effects of an adjacent metal roof.

Eagle Antenna, Ebay seller, pictures a Gain Master virtually sitting on the top of a 4 element beam which appears to be a Sirio SY-4.

 

[Marconi]

Eagle Antenna, Ebay seller, pictures a Gain Master virtually sitting on the top of a 4 element beam which appears to be a Sirio SY-4.

AB, do you have a link for this picture on Ebay?

Such as don't have a ground plane as some very similar antenna do?

AB I read this Sirio idea to likely be suggesting, the Gain-Master does not need radials...since it's a center-fed 5/8 wave antenna.

And IMHO the center fed GM is also not similar to most of the other 5/8 wave vertical antennas...which are mostly end-fed.

When I installed my 1st GM I tested the match on a P/U pole that was low and set about 9' feet high. I had the antenna I just took down laying on the ground right below the new GM. The GM match was not showing a good match. So, I moved the antenna away from the mast and the match was near perfect and improved on raising.

I talk about this experience with Bob85 somewhere on this forum and he too was puzzled by his results with his GM set low to the ground. I never tried to duplicate his problem or mine. My results were different from what Bob describe about with his GM. That was my mistake not to try and duplicate those results, so I'm not completely sure what happened back then.

 

[Alabama Buckeye]

AB, do you have a link for this picture on Ebay?

As seen right now 1330L 08.04.22
Full URL not accessible
Seller eagle_antenna (4866), best I can provide.
Ebay.com
enter Gain Master
Top of the Listings
Sirio Gain-Master Hi-Tech Fiberglass 5/8 Wave 10m & CB Base Antenna $189

I'm certain the GM feed point is 4-5" above the boom over a Sirio SY27-4, half way between Driven and 1st Director; which wouldn't seem entirely balanced.

I struggle with MacBook copying and paste. Best I can do is take screen shot and damn thing is bound only for email. I hate it. There must be a reach around, I just don't know it.
Near 25yr Windoze confuser user, ACER is on the fritz.

 

[AudioShockwav]

I'm certain the GM feed point is 4-5" above the boom over a Sirio SY27-4, half way between Driven and 1st Director; which wouldn't seem entirely balanced.

The bottom of the Gain Master is not the feed point, it is not like the Imax antenna.
It requires no ground radials.

73
Jeff

 

[Alabama Buckeye]

I read this Sirio idea to likely be suggesting, the Gain -Master does not need radials...since it's a center-fed 5/8 wave antenna.

I was of the understanding 1/2 wavelength and longer don't require a Ground Plane. Whether that's true or not, I can't argue with experience.

I used the original Imax GPK as it may or may not have resolved my RFI issues with the neighbors. As it happens I also added a Fugly Choke Balun at the same time. The Imax GPK was tested/reviewed for validity of purpose and deemed theoretical at best. I never believed it added any benefit in my receive.

Recently I put aside the 4ea x 6' fiberglass radials in favor of 4ea x 102" SS whip antennas lengthened to 103". Several over the hill local region neighbors are now reachable. They could always hear me but I couldn't hear them until now. And I feel the received DX traffic has also increased remarkably; but, that may be entirely imagination.
Only recently have I made my first contact with Australia. Again, it may be conditions were simply in my favor.

 

[Alabama Buckeye]

The bottom of the Gain Master is not the feed point, it is not like the Imax antenna.
It requires no ground radials.

73
Jeff

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

 

[Marconi]

As seen right now 1330L 08.04.22
Full URL not accessible
Seller eagle_antenna (4866), best I can provide.
Ebay.com
enter Gain Master
Top of the Listings
Sirio Gain-Master Hi-Tech Fiberglass 5/8 Wave 10m & CB Base Antenna $189

I'm certain the GM feed point is 4-5" above the boom over a Sirio SY27-4, half way between Driven and 1st Director; which wouldn't seem entirely balanced.

I struggle with MacBook copying and paste. Best I can do is take screen shot and damn thing is bound only for email. I hate it. There must be a reach around, I just don't know it.
Near 25yr Windoze confuser user, ACER is on the fritz.

AB, I saw the image on Ebay, thanks.



However, it's just an image so, I figure that Alexis my have to try his idea on his beam to solve this Delima. Again, I can't be sure of my idea here...it was some years ago and I never tried to duplicate the results I saw.

I might try a GM model over a 4 element yagi and see what that suggests.

 

[Alexis Mercado]

AB, I saw the image on Ebay, thanks.

View attachment 60101

However, it's just an image so, I figure that Alexis my have to try his idea on his beam to solve this Delima. Again, I can't be sure of my idea here...it was some years ago and I never tried to duplicate the results I saw.

I might try a GM model over a 4 element yagi and see what that suggests.

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 ?

 

[Beetle]

Install it however you want. Take careful measurements, take pictures and take notes (legible ones, not like the ones I generally take). Use these data as your baseline. Then make adjustments (ONE at a time). Take careful measurements, pictures, etc as before.) Remember, when Guglielmo Marconi was ready to send his first radio transmission, he didn't have access to the Internet to find out if his antenna would work.

And I'm pretty sure he didn't know what SWR was, at least at first.