HY-GAIN SPT-500 or Tornado 27?

[W5LZ]

Because of how the gain was stated I wouldn't place much faith in it. From experience, that 5+ dB gain is more like 2+ dB gain, the typical difference between a 1/2 wave and a 5/8 wave antenna. Just depends on how it's measured and since it wasn't stated, and since the quote comes from the manufacturer, it's on the optimistic side, sort of.
It should perform as well as any other antenna of the same type mounted in the same place and way.
- 'Doc

 

[T23]

How do y'all think this will do 20 - 25 foot in the air? As far as local, skip is irellivent because I have worked the east coast and scotland on a loaded speaker wire with var. cap. zip tied to a pvc vertical pole. heh.. heh..

T23

 

[BOOTY MONSTER]

if local is your priority try a starduster/M400 or a merlin .

 

[binrat]

I would go with it at that height.

 

[W5LZ]

Height is usually the best at whatever you can manage. More is better, but if you can only do so much, then that's as good as it's practical for you. 20 or 30 feet should do just fine.

Gain. That's a complicated subject, all kinds of factors get involved with it. Without that third letter not included in the advertised figure you have no idea what it's being compared to. If that third letter is a 'd' then it's compared to a dipole. If it's an 'i' then it's being compared to an isotropic antenna. For any 5/8 wave antenna a gain of 5 dB means it could be being compared to a rubber duck, or a beer can laying in the grass, it doesn't tell you anything. A typical 5/8 wave antenna has something like 1.2 dBd of gain. The same antenna'sgain expressed in dBi would be something close to 3.4 dBi. The exact same gain in either case, just a different way of measuring it. Big numbers sell antennas so guess what 'they' are trying to imply! Same old B.S. Sorry...
- 'Doc

 

[The DB]

Height is usually the best at whatever you can manage. More is better, but if you can only do so much, then that's as good as it's practical for you. 20 or 30 feet should do just fine.

Gain. That's a complicated subject, all kinds of factors get involved with it. Without that third letter not included in the advertised figure you have no idea what it's being compared to. If that third letter is a 'd' then it's compared to a dipole. If it's an 'i' then it's being compared to an isotropic antenna. For any 5/8 wave antenna a gain of 5 dB means it could be being compared to a rubber duck, or a beer can laying in the grass, it doesn't tell you anything. A typical 5/8 wave antenna has something like 1.2 dBd of gain. The same antenna'sgain expressed in dBi would be something close to 3.4 dBi. The exact same gain in either case, just a different way of measuring it. Big numbers sell antennas so guess what 'they' are trying to imply! Same old B.S. Sorry...
- 'Doc

In an additional note, don't forget the point of advertising is to get you to purchase something, not necessarily give you accurate information. Some companies have more accurate figures than others.


The DB

 

[W5LZ]

Oh, the ad can be perfectly true in what it says. It's just that it doesn't say enough to qualify the 'truth' they told. Guess that's up to the buyer knowing what he's reading. If that buyer makes an assumption that isn't what the seller meant, is that the seller's fault?? Really??
- 'Doc

 

[BOOTY MONSTER]

figures don't lie ..... but liers can figure

 

[The DB]

Oh, the ad can be perfectly true in what it says. It's just that it doesn't say enough to qualify the 'truth' they told. Guess that's up to the buyer knowing what he's reading. If that buyer makes an assumption that isn't what the seller meant, is that the seller's fault?? Really??
- 'Doc

A half truth is worse than a lie. If they only put part of the fact in question in the advertising and you neglect to do your research, I would put the blame on both as both sides were negligent.


The DB

 

[hotrod]

ive never compared these 2 . but i do have a sirio 2016. yes it does have somewhat thin tubing . but since spring of 09 when i put it up its seen ice storms cooulpe times
seen 70 mph winds still going strong. the p-500 will be a stiffer antenna yet.
when i got my 2016 the NEW p-500 wasnt out yet, otherwise i MAY have gotten it

 

[Needle Bender]

I presume the 5.3dB figure is compared to a 1/4 wave GP.

I prefer the larger, stronger radials of the P500 to the Tornado27, and have had fantastic luck helping others to erect theirs when placing the current node right at 1 wave length above ground, sometimes actually seeing signal improvement over when it was dropped to that height compared to having been somewhat higher.

The current node is at 8' down from the top hat, so if the radials were located 22' above ground it may be the 'sweet spot'.

And the early version was 22' 9.5" to the top hat, I would be interested in trying a new one out for tuning at that length, especially since there seems to be several discrepancies regarding the correct length for tuning @ 27.2mhz.

 

[Shockwave]

5.3 db is laughable considering reality for a 5/8 wave is a little over a db. Even if it were dbi it would only be about 3.35 dbi. Having said that, it's still a no brainer that the SP-500 is the better antenna. Full length radials make the biggest difference between the two. The 5/8 wave is a antenna that really likes to see a good ground plane under the radiator. Compromises in this area tend to shift power from the patterns low angle primary lobe, to higher elevations. Both matching networks are efficient enough that you will not notice gain differences in this area.

 

[W5LZ]

There are a lot of factors which will determine how much gain an antenna will have in any given situation. Those factors include it's physical characteristics, where and how it's located/mounted, how high it is, and how well it's tuned (resonant and impedance matched). Varying any of those things (plus the color of socks you are wearing) will vary the 'gain' of any antenna. That's the reason for 'standardizing' antenna testing, you are 'leveling the playing field'. And the biggy is propagation when you do that sort of comparing on the air. There's no way to 'level' that 'playing field' completely, 'Momma Nature' always has the last word. So, putting too much emphasis on any one of those things isn't a good idea without considering -all- the rest of them.
If comparing that 5/8 wave to a 1/4 wave that 5 dB is still sort of huge. A 1/4 wave when compared to a 1/2 wave (the standard) has a negative gain factor somewhere close to a dB. That would make a 5/8 wave's gain something like +2 or +3 dB. Still a little bit optimistic with the quoted 5 dB. That's a 'ballpark' guesstimate, not accurate by any means, but close. Some 'ballparks' are bigger than others. And for some reason the 'bigmac' I get in that bag don't never look like the one on the sign, you know??
- 'Doc

 

[Needle Bender]

5.3 db is laughable considering reality for a 5/8 wave is a little over a db. Even if it were dbi it would only be about 3.35 dbi. Having said that, it's still a no brainer that the SP-500 is the better antenna. Full length radials make the biggest difference between the two. The 5/8 wave is a antenna that really likes to see a good ground plane under the radiator. Compromises in this area tend to shift power from the patterns low angle primary lobe, to higher elevations. Both matching networks are efficient enough that you will not notice gain differences in this area.

After using one for years I'm not laughing, and as I stated previously,

I presume the 5.3dB figure is compared to a 1/4 wave GP.

- I believe they might have been using a 1/4 wave as reference, or dBq.
1/4 wave = -.85dBi
Isotropic Source = .85dBq
1/2 wave dipole = 2.15dBi or 3dBq
5/8 = 1.2dBd or 4.2dBq and the Penetrator500 radiator measures easily a foot longer (including it's top hat) than any other 5/8 radiator so perhaps on a test range it might have 1.1dB additional 5/8 gain or 5.3dBq. I don't know, I haven't tried it there, but...

I wonder what the dB difference would measure at the distance where the higher departure angle of a 1/2 wave provides zero signal but the lower Departure angle of a 5/8 still provides an s3 signal at the receiving antenna location?

That's what happened when I compared a metal 1/2 wave against the Penetrator500. 55 miles away, no signal heard on the Ringo 1/2 wave, but s3 on the P500 (both tuned with an MFJ-259B) yet on a test range they are only supposedly 1.2dB different.
Oh wait! Maybe his meter was out of calibration and was set to only .4dB per s unit.

OK, take the Gainmaster for instance, it's only a 5/8 but you claim it keeps up with your modded Vector but on a test range it would have the same gain as a bottom fed 5/8 since they are both 5/8, and would be less than the stock Vector which Sirio claim is 4.15dBi.

Maybe what happens in the real world, and at distance, shows a much greater propensity for more realized gain (translating into as much as 2-3 s units difference between different antenna designs) than the tiny amount of difference measured on a near field test range.
Wow, what a concept

 

[Shockwave]

After using one for years I'm not laughing, and as I stated previously,



- I believe they might have been using a 1/4 wave as reference, or dBq.
1/4 wave = -.85dBi
Isotropic Source = .85dBq
1/2 wave dipole = 2.15dBi or 3dBq
5/8 = 1.2dBd or 4.2dBq and the Penetrator500 radiator measures easily a foot longer (including it's top hat) than any other 5/8 radiator so perhaps on a test range it might have 1.1dB additional 5/8 gain or 5.3dBq. I don't know, I haven't tried it there, but...

I wonder what the dB difference would measure at the distance where the higher departure angle of a 1/2 wave provides zero signal but the lower Departure angle of a 5/8 still provides an s3 signal at the receiving antenna location?

That's what happened when I compared a metal 1/2 wave against the Penetrator500. 55 miles away, no signal heard on the Ringo 1/2 wave, but s3 on the P500 (both tuned with an MFJ-259B) yet on a test range they are only supposedly 1.2dB different.
Oh wait! Maybe his meter was out of calibration and was set to only .4dB per s unit.

OK, take the Gainmaster for instance, it's only a 5/8 but you claim it keeps up with your modded Vector but on a test range it would have the same gain as a bottom fed 5/8 since they are both 5/8, and would be less than the stock Vector which Sirio claim is 4.15dBi.

Maybe what happens in the real world, and at distance, shows a much greater propensity for more realized gain (translating into as much as 2-3 s units difference between different antenna designs) than the tiny amount of difference measured on a near field test range.
Wow, what a concept

Why not get on Hy Gain's behind and complain they didn't state what antenna they were comparing gain against? It's also worth noting the Ringo Ranger is one of the worst performing 1/2 wave antennas you can buy. Where is its counterpoise, radials, or any other method of decoupling the feedline and mast from the antenna? It has none and as a result has notorious problems with the coax and mast radiating.

Furthermore, anytime you see 3 S-Units or 18 db of gain between two single element verticals, you can bet that S meter is off as are most. Saying the GainMaster is "only" a 5/8 wave is a bit of an understatement too. Changing the feedpoint to the center has a drastic affect on how the currents are dispersed across the radiator. To the point of keeping them all in a constructive phase. Try getting the SP-500 to do this.

I'd also like to ask who is using a near field test range? "Near field" and "test range" don't even belong in the same sentence. Field tests must be done in the far field. Near field is useful for understanding the currents along a given radiator, not its gain. I don't run around the antenna holding the trusted Micronta field strength meter and neither does Sirio. I prefer a digital field strength receiver with a precise 50 ohm input impedance and a handful of calibrated attenuators to double check against at a distance of miles.

PS: With your test between the Ringo and SP-500 in mind, would you now feel comfortable claiming the SP-500 has 18 dbd as a result? I hope not.