New antenna from Sirio Gain-Master

[Marconi]

And I'll keep looking, too!

But considering the genius emanating from Sirio, I'm wondering, if the .64 IS better, why wouldn't they choose a .64 over a .625, especially when the impedance is supposed to be closer to 50 ohms prior to the introduction of a matching network...?
Things that make you go, "Hmmmmm".

007, I'm assuming my models @ http://www.worldwidedx.com/members/marconi-albums-i-10k-625-vs-i-10k-64.html are correct or close enough to make some conclusions about the issue you raise..."why" Sirio did not make the GM a .64 rather than a .625.

I've added the source impedance reports for both antennas and I think the differences may not be as significant as I may have implied earlier.

If you look close at the free space pattern results for both you may notice that the .625 exhibits a marked lowering of several degrees in the maximum angle of radiation near the horizon---even while the gain is reduced slightly below that of the .64. Is this the gain difference the CB world clamors about while claiming the .64 makes more gain?

Again we have differences here that are small, and since Sirio elected to use the free space model to make their comparisons, I would think it natural to want this angle to be at its lowest point to the horizon and sell the customer on the idea of the gain advantage noted in yellow in their manual as they are doing.

IMO, the .625 has a slight advantage over the 1/2 wave and the .64 wave. I'm just not sure how the real world results will work out with the Gain Master. I believe a lot of guys will be looking for "on/off switch" kind of differences, and then I think there will be some complaining.

BTW, I tweaked my 22.6' foot 5/8 wave down to 20.8' feet and it shows a 4% increase in gain over real Earth to 3.77 dbi, and in free space the maximum angle went down from 18 degrees with 1.91 dbi gain to 10 degrees with a 1.94 gain, so maybe you guys with 5/8 wave antennas might try and tune them a little shorter...rather than going longer.

 

[HomerBB]

Interesting thought on the shortening of the 5/8. I may have to try it . . .

 

[BOOTY MONSTER]

BTW, I tweaked my 22.6' foot 5/8 wave down to 20.8' feet and it shows a 4% increase in gain over real Earth to 3.77 dbi, and in free space the maximum angle went down from 18 degrees with 1.91 dbi gain to 10 degrees with a 1.94 gain, so maybe you guys with 5/8 wave antennas might try and tune them a little shorter...rather than going longer.

interesting ............................... 248 inches is what maco recommends for the overall length of their 5/8WGP .

http://www.macoantennas.net/assembly/support2/V58I072810_Web.pdf

things that make you go hmmmmmmmm................................

 

[LightFoot]

Well, I called H&Y spoke to a nice lady on the phone in respect to the Gain-Master. They will have it in stock by the end of this month. Price is $129.99 plus shipping is $20.33 to Shipping price is good. Also when they have it in stock they will post it at their side . Best wishes and regards.........LightFoot with the Golden Wave...............................

 

[Marconi]

Well, I called H&Y spoke to a nice lady on the phone in respect to the Gain-Master. They will have it in stock by the end of this month. Price is $129.99 plus shipping is $20.33 to Shipping price is good. Also when they have it in stock they will post it at their side . Best wishes and regards.........LightFoot with the Golden Wave...............................

That's good news Thundir, the price sounds much more reasonable than I thought. It's in line with their New Top One price.

BM, Sirio has also elected to go shorter with their New Vector, so maybe shorter is the new "in-thing" in antenna design. We're still waiting for some New Vector owners to give us some real comparison reports, but I think most are scared to talk-up.

Homer, the devil might be in the details with this idea.
The source impedance just about doubles with the shorter radiator, so the matcher will have to work harder to make a match. It is also possible these models are giving some false indications, because they are not matched...and in this case I am showing segment errors for the radial elements. This error indicates my input does not show the necessary number of segments for the length of the radial elements.

 

[Oggy]

Since the materials used don't look that hot to me; it looks like they might have priced themselves out of the market.
That video - while appreciated - makes the antenna look a bit shoddy.

We will see what happens.

Hello everyone from the UK. I see you posted my video on here. I do intend to do a side by side with my Shakesphere ABS1600 Bigstick within the next couple of weeks. I'm curious Robb why my video makes the GM look shoddy?.....73's Dave

 

[LightFoot]

It would be nice to see it side by side with the Imax2000 and the MacoV58. Hello Oggy. My Buddy plans on purchasing this antenna the end of the month. If it smokes his Imax2000 everyones planning on trying it out. Best regards and wishes. LightFoot with the wave................

 

[Oggy]

Hello Lightfoot .........nice to finaly post on the Worldwide Radio Forum. I have had mine (got it direct from Sirio in Italy) around a week ago. Due to my job ,it will be a couple of weeks before I do my side by side with it. As I said on my video, I feel it's well built .I think it will work very well and I guess, this is what will make it worthwile for most. For most in the UK 500 Watts is plenty. But I know Stateside your like your power, so I guess this may be a bit of a down side for you guys.......I do intend running it QRO on 10 meters too....The UK Waving A Hand!!....Dave M0OGY (26CT110)

 

[Shockwave]

BTW, I tweaked my 22.6' foot 5/8 wave down to 20.8' feet and it shows a 4% increase in gain over real Earth to 3.77 dbi, and in free space the maximum angle went down from 18 degrees with 1.91 dbi gain to 10 degrees with a 1.94 gain, so maybe you guys with 5/8 wave antennas might try and tune them a little shorter...rather than going longer.

I find this very interesting that a change of a few inches in radiator length would drop the TOA by an additional 8 degrees. Many years ago I had a conversation with a colleague concerning the possibility of downward beam tilt with a single element FM antenna. He suggested it was possible to manipulate the take off angle by adjusting the radiator length. The change of 8 degrees is more then I expected because I have not seen that much difference working with the Sigma design.

Also, the differences in the matching network required for a .625 wave and a .64 wave are nearly identical. Only a slight change in the tap point should be required to match either one. One reason companies are using the free space model is because it eliminates variables with the height the antenna is mounted above ground.

 

[CDX-007]

Interesting eznec results but I've already been there far too many times to even consider that possibility.

Having owned several shortened or 'loaded' 5/8 such as the Hy-gain CLR-II, Spectrum 1600, Maco V-5/8 and an Antenna Specialists Jam Ram, I can testify the Penetrator / I-10K / Sigma5/8 / Tayor GLR4 outperformed all of the above by about* the same 1.5 S-units against each, to wherever I was talking.

Makes me wonder about all those posts I've read with regard to eznec sometimes being inaccurate.

Your actualized results may vary...



...not.:bdh:


*Taking into account the vast differences of up to 10,000dB in S-meters.

 

[BOOTY MONSTER]

if a 5/8wgp only has 1.2 db of gain over a dipole how does adding a few inches to it add 9 db (1 1/2 s-units) of gain ?

 

[HomerBB]

Homer, the devil might be in the details with this idea.
The source impedance just about doubles with the shorter radiator, so the matcher will have to work harder to make a match. It is also possible these models are giving some false indications, because they are not matched...and in this case I am showing segment errors for the radial elements. This error indicates my input does not show the necessary number of segments for the length of the radial elements.

Well, If you get more clarification I may try it. As for the 5/8 I've got up, it is giving some good results. I am hearing stations clearly that I had difficulty with on with other antennas, but as I've noted elsewhere, I can not reasonably say how it compares to the Qv4k until I get it back into the air. One note, the Vector at 10' off the ground has heard some stations as well as the 5/8 at 35'. This might have more to do with the different radios than not. The old 88 with good ears is on the 5/8, and an old Cobra 87gtl with great ears is on the Vector.

Back to the length. Give me a really good reason to want to change the length. Keep saying things like better TOA. Do that, and I'll end up shortening the 5/8 and retapping the coil by Friday.

 

[Marconi]

I find this very interesting that a change of a few inches in radiator length would drop the TOA by an additional 8 degrees. Many years ago I had a conversation with a colleague concerning the possibility of downward beam tilt with a single element FM antenna. He suggested it was possible to manipulate the take off angle by adjusting the radiator length. The change of 8 degrees is more then I expected because I have not seen that much difference working with the Sigma design.

Also, the differences in the matching network required for a .625 wave and a .64 wave are nearly identical. Only a slight change in the tap point should be required to match either one. One reason companies are using the free space model is because it eliminates variables with the height the antenna is mounted above ground.

Hey Shockwave, I'll scan my reports and see if I can post it all to my album. The models only have 5 wires, and it should be easy to duplicate on your end. If you would like to enter this into your Eznec, which I think allows for more segments, I would appreciate the feed back. I can also send the Eznec files via email if I can find them.

I don't have anything or anyone to really compare notes with. I have compared some other Internet modeling presentations for the 5/8 wave for 2 meters that was presented in a published report for one of the Radio Magazines. My results were almost identical, and that gives me some confidence.

I sure wished WWRF would allow pdf files and I could post a slide show of each model. As it is I have to scan and load each page individually and sometimes I have to go back a fix the size of the images my scanner makes. It is not easy and maybe WWRF doesn't even like this type of info posted, because I'm sure it takes up space. If this is true, them let me know and I will have to send you the files via email. Robb how say you?

 

[CDX-007]

if a 5/8wgp only has 1.2 db of gain over a dipole how does adding a few inches to it add 9 db (1 1/2 s-units) of gain ?

Less loss in the matching network due to less loading?

Lower TOA?

Measurements taken in the real world instead of in a near-field RF test chamber?

Hard to say without doing exhaustive testing utilizing the type of test equipment as have Sirio, but when I see results on both mine and the other meter I don't argue with it, I just move along the latest test antenna that gets smacked down.

 

[CDX-007]

Well,...

Back to the length. Give me a really good reason to want to change the length. Keep saying things like better TOA. Do that, and I'll end up shortening the 5/8 and retapping the coil by Friday.

Now there would be a great comparison idea! I'd LOVE to see if your results mirror mine.