-
You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
New antenna from Sirio Gain-Master
- Thread starter dxswe
- Start date
if your dead set on going with a fiberglass antenna, and you have any wind at all,,, id go with the gainmaster. my gainmaster has been up (40' to the base) in a tree for a year with no issues,, but my imax on the tower broke in the wind within 3 months of having it up. now only aluminum antennas,, and im not going back up in the tree as long as the gainmaster keeps working.
I've had my gainmaster up for a year. There have been no problems with this antenna. It replaced a maco v5000 and seems to me to be as good, maybe a little better. Local and long distant contacts have been great. I am well pleased with the gainmaster.
I likes mine to! Ran mine at the same tip height as my Imax for comparison for a month or so then sold my imax. Less noise on the gainmaster no cmc issues and slightly better signal on the real long haul dx, no signal difference local or short skip. Is it worth the extra Money? Both antennas retail for silly prices here ,$ 250 to $300 I wouldn't recommend either at those prices. And I always paint glass antennas now ( lasts longer in the Aussie sun)
A Gain-Master in clean air even 10' above the roof line (30 feet to the feed) works pretty well.
Sirio recommends just that:
"Be sure that the antenna is installed at least 3 meters(9.84', call it 10') above the roof of the nearest building and 5-6 meters above or away from any metal objects in the area."
Their literature is not clear on what they mean by a metal object, should it then be installed at the higher 5-6 meters for a metal roof?
What about the antenna mast itself if it is metal, then should one use non metal mast and keep it at least 5-6 meters(16.4'-19.7') away from your nearest next section of mast ?
I pulled the above quote from the Sirio website, which has a pdf on the gainmaster mounting instructions...
"Be sure that the antenna is installed at least 3 meters(9.84', call it 10') above the roof of the nearest building and 5-6 meters above or away from any metal objects in the area."
Their literature is not clear on what they mean by a metal object, should it then be installed at the higher 5-6 meters for a metal roof?
What about the antenna mast itself if it is metal, then should one use non metal mast and keep it at least 5-6 meters(16.4'-19.7') away from your nearest next section of mast ?
I pulled the above quote from the Sirio website, which has a pdf on the gainmaster mounting instructions...
Last edited:
I am finding it impossible to know if the Gain Master is really better than a conventional 5/8 wave and I appreciate that TOA is not the only factor relative to a good antenna. Size/shape/CMC in feeder issues/mounting options/height options and sensitivities to static and noise susceptibility all come into it. (all relative to the specific location and ground quality conditions)
I appreciate the GM is a 5/8 dipole equiv as opposed a 1/2 wave and most plots that are provided are for the 1/2 wave standard dipole. I wonder if Sirio are stretching the truth... in their diagrams they show radiation angle of 0 degree for the GM (I think that is free space ?), their diagram just says "Typical radiation pattern" (does not exist in reality, what is typical, typical should mean over earth surely... typical cannot be in non existent free space) Comparatively they show a "conventional 5/8" as having a elevation angle of 24 degrees. That does not appear to the the case either as we know from diagrams here:
Taken from:
http://www.dx-antennas.com/5-8 wave vertical.htm
That 0.5M above earth it has most gain at 16 degrees TOA. That is an 8 degree discrepancy for starters.
As does the humble 1/2 wave, 16 degrees TOA:
Taken from here:
http://www.dx-antennas.com/Half wave vertical.htm
A 1/2 wave dipole above ground at various heights looks rather different than the plot on Sirio's literature...(also would a 0 degree take off not just get absorbed by ground, hills, mountains, buildings, terrain therefore attenuating the signal en route to the atmospheric layers we are interested in ?)
The caveat being... I suspect in reality above actual earth/ground a 0 degree take off is pure fantasy land.
Vs.. at 0.75 wave length of ground. (looking a lot more like 18-20 degrees on this plot, with a nice cloud warming plume on top)
Image taken from here:
http://www.hamuniverse.com/wb4yjtdipolepatterns.html
I am doing my best to make sense of this but am having difficulty. Maybe the widely reported 1 S point improvement should just be accepted as a oft reported signal improvement in the vast majority of user set ups. i.e. set ups that do not have proper size ground radials that the 5/8 design requires to provide some TOA gain over a 1/2 wave monopole. i.e. relative to 5/8 waves that do not have full length 1/4 wavelength radials.
The story (1S point) might be different if all those IMAX's/827's/GPE5/8 etc. had full size 1/4 wave length radials or a massive ground plane of some kind. Your thoughts are welcome. I am not expert just trying to add 2 and 2 and make 4. Thanks
PS I do wonder how much of a difference the 5/8 wavelength of the GM makes as opposed to 1/2 wavelength where the plots are often derived for dipoles.
I appreciate the GM is a 5/8 dipole equiv as opposed a 1/2 wave and most plots that are provided are for the 1/2 wave standard dipole. I wonder if Sirio are stretching the truth... in their diagrams they show radiation angle of 0 degree for the GM (I think that is free space ?), their diagram just says "Typical radiation pattern" (does not exist in reality, what is typical, typical should mean over earth surely... typical cannot be in non existent free space) Comparatively they show a "conventional 5/8" as having a elevation angle of 24 degrees. That does not appear to the the case either as we know from diagrams here:
Taken from:
http://www.dx-antennas.com/5-8 wave vertical.htm
That 0.5M above earth it has most gain at 16 degrees TOA. That is an 8 degree discrepancy for starters.
As does the humble 1/2 wave, 16 degrees TOA:
Taken from here:
http://www.dx-antennas.com/Half wave vertical.htm
A 1/2 wave dipole above ground at various heights looks rather different than the plot on Sirio's literature...(also would a 0 degree take off not just get absorbed by ground, hills, mountains, buildings, terrain therefore attenuating the signal en route to the atmospheric layers we are interested in ?)
The caveat being... I suspect in reality above actual earth/ground a 0 degree take off is pure fantasy land.
Vs.. at 0.75 wave length of ground. (looking a lot more like 18-20 degrees on this plot, with a nice cloud warming plume on top)
Image taken from here:
http://www.hamuniverse.com/wb4yjtdipolepatterns.html
I am doing my best to make sense of this but am having difficulty. Maybe the widely reported 1 S point improvement should just be accepted as a oft reported signal improvement in the vast majority of user set ups. i.e. set ups that do not have proper size ground radials that the 5/8 design requires to provide some TOA gain over a 1/2 wave monopole. i.e. relative to 5/8 waves that do not have full length 1/4 wavelength radials.
The story (1S point) might be different if all those IMAX's/827's/GPE5/8 etc. had full size 1/4 wave length radials or a massive ground plane of some kind. Your thoughts are welcome. I am not expert just trying to add 2 and 2 and make 4. Thanks
PS I do wonder how much of a difference the 5/8 wavelength of the GM makes as opposed to 1/2 wavelength where the plots are often derived for dipoles.
Last edited:
Well, my GM sucked until it went up in the air alone. When I had the Penetrator up a 1/2 wave away the GM lost 1.5 S-units to the Imax which had been on the same mast. Removing the Penetrator from it's airspace, the GM then outperformed everything I had on that mast, and also beat the Penetrator on it's own mast by 2dB.I am finding it impossible to know if the Gain Master is really better than a conventional 5/8 wave and I appreciate that TOA is not the only factor relative to a good antenna. Size/shape/CMC in feeder issues/mounting options/height options and sensitivities to static and noise susceptibility all come into it. (all relative to the specific location and ground quality conditions)
I appreciate the GM is a 5/8 dipole equiv as opposed a 1/2 wave and most plots that are provided are for the 1/2 wave standard dipole. I wonder if Sirio are stretching the truth... in their diagrams they show radiation angle of 0 degree for the GM (I think that is free space ?), their diagram just says "Typical radiation pattern" (does not exist in reality, what is typical, typical should mean over earth surely... typical cannot be in non existent free space) Comparatively they show a "conventional 5/8" as having a elevation angle of 24 degrees. That does not appear to the the case either as we know from diagrams here:
Taken from:
http://www.dx-antennas.com/5-8 wave vertical.htm
That 0.5M above earth it has most gain at 16 degrees TOA. That is an 8 degree discrepancy for starters.
As does the humble 1/2 wave, 16 degrees TOA:
Taken from here:
http://www.dx-antennas.com/Half wave vertical.htm
A 1/2 wave dipole above ground at various heights looks rather different than the plot on Sirio's literature...(also would a 0 degree take off not just get absorbed by ground, hills, mountains, buildings, terrain therefore attenuating the signal en route to the atmospheric layers we are interested in ?)
The caveat being... I suspect in reality above actual earth/ground a 0 degree take off is pure fantasy land.
Vs.. at 0.75 wave length of ground. (looking a lot more like 18-20 degrees on this plot, with a nice cloud warming plume on top)
Image taken from here:
http://www.hamuniverse.com/wb4yjtdipolepatterns.html
I am doing my best to make sense of this but am having difficulty. Maybe the widely reported 1 S point improvement should just be accepted as a oft reported signal improvement in the vast majority of user set ups. i.e. set ups that do not have proper size ground radials that the 5/8 design requires to provide some TOA gain over a 1/2 wave monopole. i.e. relative to 5/8 waves that do not have full length 1/4 wavelength radials.
The story (1S point) might be different if all those IMAX's/827's/GPE5/8 etc. had full size 1/4 wave length radials or a massive ground plane of some kind. Your thoughts are welcome. I am not expert just trying to add 2 and 2 and make 4. Thanks
PS I do wonder how much of a difference the 5/8 wavelength of the GM makes as opposed to 1/2 wavelength where the plots are often derived for dipoles.
The GM is a center-fed 5/8 therefore a 'balanced' antenna needing to be as close to free space as possible to keep that low TOA.
I've also seen the GM beaten in several installations by an Imax, Sirio 827 and Sirio Tornado, but those installations were not able to keep the GM well away from other metal objects.
It's very fickle but when happy, unbeatable - IMO.
Thanks for the input.I only have one antenna set up at a time being a mobile base station so can get it up above the nearest objects by 5m.
I have no complaints just an inquisitive mind and a curious grass is greener feeling (which could well be wrong). Not helped by the fact that one local station to me cracks out very well (local and DX) using an IMAX2000. Though he has a perfect salt water ground plane.. i.e. the sea so maybe it is not a fair comparison against a more typical ground based station with only average earth/soil conditions.
I have no complaints just an inquisitive mind and a curious grass is greener feeling (which could well be wrong). Not helped by the fact that one local station to me cracks out very well (local and DX) using an IMAX2000. Though he has a perfect salt water ground plane.. i.e. the sea so maybe it is not a fair comparison against a more typical ground based station with only average earth/soil conditions.
I have a 16' 4-section military telescopic mast which collapses to about 5'. Reading your post had me wondering if you've got the same type of mobile mast. Each section has 2 spring buttons which pop into holes in the next section down when fully elevated.
In THAT type of rover, I'd seriously encourage you to snag a Proton99 and do a little fiberglassing mod to strengthen it. It's construction quality leaves much to be desired but the performance is surprisingly good. mine proved to be only a needle width below the Imax in the same 18' high mobile-rover installation but it breaks down to FOUR ~55" sections which makes it a dream to transport. It outperformed my A99 by a full S-unit so I'm sticking with my beefed-up Proton99 for camping & roving. It's also been on 1 backpacking trip! I used the 2" x 2.5" x 58" box it came in, tied to my backpack. Kicked arse from the 9000' peak of Quartz Mtn!
(Only had a 2950DX and a 15lb XS XP750 22AH battery. Incredible battery! Avail for ~$99!)
I also tried my GM but it didn't seem to get anyone coming back, made me feel handicapped in that installation, and I had it almost 20' above the car roof by adding a mast section into the top of the 16 footer.
Whatever you end up with, HAVE A BLAST!
2dB eh? How did you measure that? I can but I have a Flexradio 6000 series however the trouble is though that even in the time it would take me to swap the coax going to two permanently installed antennas the propagation could've changed the signal by more than 2dB. Let alone in the time it takes to take down an antenna and put up another antenna on the same mast.
I have a local friend that uses the analog meter on his Pro3 and I've got him well trained! - LoL!!
He had me on the Penetrator at S-9+1dB, all day, everyday for months.
Pulled it down and replaced it with the GM, same radio, coax, mast, height. S-9+3 for days & days & days & days...
We almost NEVER had any difference in signal strength between us, our signal strength remains constant, base to base @ 10.15 miles (Google Earth), (kinda like long range near field
) that is until I recently moved.BTW, the Imax2K was just under S-8 on that mast, coax, radio, etc...