New Sirio 1/2 wave Gain Master

[vkrules]

Simon is very well known ,and regarded , particularly outside the US .
The new GM certainly looks like it might be a T2LT in a fiberglass radome.
If you allow for VF of insulated wire and the fact that the Europeans center frequency is higher than the US the length looks about right to me.
Having built many T2LTS I can tell you with certainty that tuning the top wire does unbalance the ant and can raise the impedance but usually not enough to be a problem.
Any way we are all just guessing we will have to wait for someone to purchase one .

 

[M0GVZ]

Simon is very well known ,and regarded , particularly outside the US .

Simonthewizard of Youtube fame Simon?

Probably is well regarded amongst the less knowledgeable section of the CB fraternity. Personally I find much of what he says in his videos and on his website the most cringeworthy bollocks there is especially when he bleats on about that Klaus guy who mods CBs.

 

[Marconi]

Simon is very well known ,and regarded , particularly outside the US .
The new GM certainly looks like it might be a T2LT in a fiberglass radome.
If you allow for VF of insulated wire and the fact that the Europeans center frequency is higher than the US the length looks about right to me.

I agree with VK regarding Simon.

I just took it for granted that the New Gain Master 1/2 wave was similar to the 5/8 wave. VK makes some good points about the short overall length we see posted. In both models I posted above, neither considered any of these factors.

Any way we are all just guessing we will have to wait for someone to purchase one .

We will probably know soon enough.

 

[Marconi]

You have been telling us for years there is nothing special about 5/8waves,
I was not convinced of that until Henry educated me, up to that point I sort of believed the BS that 5/8wave antenna builders promote,

Bob, I got good results with my first real 5/8 wave...the I-10K from Jay in the Mojave. This was the first antenna I bought to compare to my Starduster. I like Jay's antenna and it worked fine, but it didn't seem to fare much better than my SD'r.

So I started reading trying to find out why. I read the following article in the ARRL Antenna Compendium Volume 1, as noted in the PDF attachment below. I've repeated this article in previous discussions before, but I don't think it was well received, so I didn't bother to include it all. I tried to find a link on this forum for the full article, but no luck. It use to be on the Internet however.

5/8waves only have a gain advantage at low angles due to their extra 1/8wave of height of current maxima if the loss in the matching is equal in both antennas,

The first part up to the word "maxima" is my believe too. The rest of your words about matching...makes a good point as well.

when mounted at the same tip height the 1/2wave has a small advantage over the 5/8wave,

I haven't tried that yet, but I will post my models results here if I don't forget.

stick that 1/2wave gainmaster at the same tip height & let us hope the 1/2wave gainmaster has the same magnitude of matching loss as the 5/8 version.

Maybe DB can handle this one...I don't know how to add Eznec's matching feature to a model.

Among other articles that I rely on, Figure 3, on page 102, is the chart of importance to my claim about 5/8 wave antennas not being special, as long as the current maximums are about the same height.

Thanks for your comments.

 

[RadioDaze2.0]

Good debate on here as always, as expected on this forum. I can only convey my initial thoughts. Mention of use on hill tops from Simon is interesting and slightly peculiar. As far as 5/8 Gain Master hilltop use I am the only person I know using one in the UK for mobile static. Understandably as they require some work to get ready.

I use one for the suspected enhanced low angle radiation for the 7,000 miles + performance over any other practical vertical omni directional antenna for mobile static. If I was going up a hill I would not take a 1/2 wave Gain Master. I would use a £25.00 Silver Rod. I hope the GM HW is not more than an Antron 99 for Sirio's sake.

It appears to me that the 1/2 GM will perform like a 1/2 wave dipole or a 1/2 wave Silver Rod, similar at least.

Many people who hill top do not use a 20ft pole (which I believe you need for GM/dipole antennas before ground losses die off a little and the unbalancing of the balanced design from the electrical qualities of the earth below is reduced), they have various other mounting methods. (tops of vans/pick up truck with a pole etc. or just 1 or 2 poles with a max height of 3M or G-clamped to gate or fence post) A 1/2 GPA (Silver Rod) is likely to have less performance losses associated with low height mounting (or close to metallic objects mounting) in my understanding relative to dipole designs.

A GM is not an ideal candidate IMO for mobile static use unless it is modified (which I do here by running the internal wiring up a fibre glass fishing rod which is cable ties to the base section of the GM) and mounted at a minimum of 20ft. Below 20ft and performance is much poorer in my experience.

My own thoughts are these are Sirio's tool angled squarely at replacing Antron 99 home bass antennas. I don't understand the mobile static commentary related to the GM HW. The practical issue putting people off for mobile static is not the length of the antenna it is the construction/design. i.e. fibre glass tubes with hose clips and associated stretching/support of the internal wiring. (very fiddly in the cold and wet especially)

Nonetheless it is interesting. I will watch this thread with anticipation of it's release and usage reports.

 

[gamegetter]

I have sent sirio an email asking if they will be producing a half wave gain master antenna.
Also asked them if it will be end fed or center fed. Don't know if they will reply, but if they do I will post back.

I have no reason to doubt anyone here, but my question is this:

Why would sirio not post the news on their website? They have a section dedicated to new products....
http://www.sirioantenne.it/news/

 

[Marconi]

Eddie,
I would not be too concerned about the 16.5ft, the wire in gainmasters has insulation and its housed inside a grp tube both of which slow the velocity of propagation,

I take back what I said earlier...that the insulation and the VF don't matter much. Bob, after I read your response above, I remembered the trouble I had using the Moxon calculators and getting different results...unless I considered the wire insulation factor in the models. Thanks to both you and Henry.

Very good points Henry or Bob, maybe both.

 

[BBB]

Wish Sirio would make a 3KW version of the Gain Master. Hopes were high when I first saw the thread. I'll stick with my Sirio 2016 for now. It looks like DNJ has some in stock again. Hey, I just noticed the model of the 2016 antenna matches the current year, haha.

 

[M0GVZ]

Wish Sirio would make a 3KW version of the Gain Master.

Why? It gets you just half a S point more than 1.5kW and barely an S point more than 750W. Given even a couple of 100W guarantees worldwide communications on 11m with a decent antenna then there is quite simply no need at all for a 3kW antenna or the need to transmit 3kW.

 

[camaro1]

sirio gainmaster HW now on there site along with the instructions and tuning table for what frequency range you want:

http://www.sirioantenne.it/hf-base/gainmaster-hw/

Manual:

http://www.sirioantenne.it/pdf/Id-442-26-02-2016.pdf

 

[Marconi]

Thanks camaro1.

 

[bob85]

I'm interested in seeing if they have a coupling capacitor for the upper 1/4wave like the original gain-master,

Spot the typo on their website & the user manual,
"Height (approx) 5560 mm / 11.2 ft with bracket" .

 

[Marconi]

Bob, the diagram shows there is a bump in the radiator, between the top end of the coax and the bottom of the wire, so there has to be something in there that will match the terrible mismatch present in this vertical HW.

Some how this seems to remind me of an old two piece Big Stick. I think they had a cap inside somewhere near the middle.

 

[Marconi]

I also compared a model at 27.205 vs. 30 mhz where I cut the radiator 10" shorter and the gain showed a bit better gain at the same maximum angle, but the match is twice as bad. So, whatever matches this one...will have to cover this span in frequency range.

Bob, do you think a capacitor will provide that kind of control?

 

[bob85]

The bump in the gainmaster could be just a circuit board to hang the coax from.
or it could have some matching element in there like the 5/8 gainmasters series coax capacitor. no doubt somebody will take one apart at some stage,

can you insert a capacitor of different values into the model to see what effect it has on the match?
i have seen one version of j-pole with a series capacitor to brodband the antenna,

I remember a capacitor probably series connected and I think a resistor or maybe a small choke for DC grounding in my shakespeare,
I'm not 100% sure how they were connected as its been a long time since I saw one let alone cut one up,

I'm not even sure what model big sticks we had here,
The antenna we called shaki big stick in the 70's had a coax tail hanging out of the bottom, it was shorter and thinner than what we called the super big stick,

my super big stick looked like the 176 with a rubber boot over the joint,
fatter and longer than the older big stick with a spiral wrap on the bottom section,

I took mine round to a local old timers in the early 80's to compare it to his coax tail big stick, they worked about the same on the same pole,

maybe somebody can tell me what models we had as I have looked online and can't find the version with coax tail hanging out of the bottom mounting tube
( not coming out of the side of the bottom tube ) .