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New Sirio 1/2 wave Gain Master

I am guessing it was an easy adaptation to compete with the A99 etc. If this antenna had been available when I purchased my A99 I would have made the purchase. I am an excellent example of a "no radial" required setup environment. I use the original 5/8 GM for 10/11/12 and the A99 for static mobile.
 
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tba02 said:
I am guessing it was an easy adaptation to complete with the A99 etc. If this antenna had been available when I purchased my A99 I would have made the purchase. I am an excellent example of a "no radial" required setup environment. I use the original 5/8 GM for 10/11/12 and the A99 for static mobile.
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I hear ya but really don't see a need to compete with such mediocrity when, over the last decade, Sirio have proven their name & quality to be of a higher class.

Not to mention the difference in cost.

How can they compete with an antenna costing £69.95 when their offering is £94.95, only £5 less than the A99's big brother the £99.95 Imax2000 or, even less but with better performance the £89.95 NV4K?
- Courtesy Nevada Radio

Not to mention the susceptibility to experiencing pattern distortion from being too close to other objects or the ground as the GM HW is also a balanced antenna.

So,

uhm,

...Why? ;)
 
Not sure how a vertical "dipole" ala Gainmaster can be a classed as balanced antenna given that one side has a nearer proximity to the ground and the mounting solution than the other half.
 
M0GVZ said:
Not sure how a vertical "dipole" ala Gainmaster can be a classed as balanced antenna given that one side has a nearer proximity to the ground and the mounting solution than the other half.
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It's a bleedin' center-feeded vertical dipole, idn't it?

...sorry, watching perhaps a bit too much of Jezza, Cap'n Slow & The Hampster in TopGear. re-runs these days :sneaky:
 
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M0GVZ said:
Not sure how a vertical "dipole" ala Gainmaster can be a classed as balanced antenna given that one side has a nearer proximity to the ground and the mounting solution than the other half.
Click to expand...

This is correct, no vertical antenna can be perfectly balanced as one side will always be closer to the earth below than the other. As you gain height, however, that difference becomes less and less very quickly, but it always exists.

If you measure earths at varying locations around a given yard, the quality of the earth will change slightly as well, more so than many realize. This, more often than not, causes even a horizontal dipole to also not be perfectly balanced either. I am remembering an article posted on a much earlier thread about the use of a the word "counterpoise" years ago, although applied a bit differently. Give me some time and I'll try and dig it up.

What we see as perfection is a rare occurrence in reality.

Needle Bender said:
...sorry, watching perhaps a bit too much of Jezza, Cap'n Slow & The Hampster in TopGear. re-runs these days :sneaky:
Click to expand...

Great show, waiting for the new Amazon version of their show... I might just give Amazon some money just to see it...


The DB
 
Needle Bender said:
I would've much preferred Sirio invest time & $$ into offering an high power version of the GM
Click to expand...

To use your own question I would ask why? All that extra power you want buys you a S point but it requires a lot more engineering, introduces a lot more issues many of which most purchasers aren't going to be competent enough to sort out and for very little benefit. If the majority of your customers are running no more than 500W there's very little incentive to design and construct an antenna of this design to work with 2kW. Certainly you'd be way beyond being able to use coax in the design as they do due to the voltage limits of the centre conductor insulation.
 
The DB said:
Great show, waiting for the new Amazon version of their show... I might just give Amazon some money just to see it...


The DB
Click to expand...
I'll echo that if Jeremy (the heavyweight champion ;)) is back.

And regarding perfection, You're right in that none of this is textbook, but it's still part of the name-of-the-game, for me at least, to keep trying to get ever closer to cresting that mountain peak.
Wouldn't it be cool if Sirio provided both a too-long top 1/2 of the GM and a chart for cutting off the correct amount (based on how high above specific soil types it will be installed) to get as close as possible to a balanced state, helping keep the famed 'near-zero° TOA'?


M0GVZ said:
To use your own question I would ask why? All that extra power you want buys you a S point but it requires a lot more engineering, introduces a lot more issues many of which most purchasers aren't going to be competent enough to sort out and for very little benefit. If the majority of your customers are running no more than 500W there's very little incentive to design and construct an antenna of this design to work with 2kW. Certainly you'd be way beyond being able to use coax in the design as they do due to the voltage limits of the centre conductor insulation.
Click to expand...

Well I'd like to know that my GM will handle at least the full power advertised
but many have complained their GM have fried at no more than 1Kw pep :( - and I'd like to be able to be confident that my hard work in installing my GM won't be wasted effort should I decide to try full-legal power on 28.4MHz.
 
NB,

doesn't sirio state the gain-master power handling is limited to 500 watts cw(continuous) and 1000 watts cw(short time)?

there is a thread on here, several years old, where shock wave talked about the break down, can't remember if it's heat related or arcing.
 
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gamegetter said:
there is a thread on here, several years old, where shock wave talked about the break down, can't remember if it's heat related or arcing.
Click to expand...

It will be internal arcing in the coax between the centre conductor and the inner of the braid.

Needle Bender said:
but many have complained their GM have fried at no more than 1Kw pep :(
Click to expand...

Quite possible depending on what the SWR was given that the power limits that coax can run at before internal arcing occur lower as the SWR rises and the GM has effectively got a coax air wound choke built into its design.
 
The error for length in feet has been there from the first info sirio published including the user manual,
 
bob85 said:
The error for length in feet has been there from the first info sirio published including the user manual,
Click to expand...

Ah, so Sirio are to blame? Odd. That's the first I recall seeing of it.

Anyway, why does the world need another, expensive, minimal power handling HALF WAVE?
For years people were crying out for Sirio to increase the power handling of the GainMaster so they don't, but come out with THIS...?

Geez.
 

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