HY-GAIN SPT-500 or Tornado 27?

[The DB]

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?

I love it when someone uses an s-meter to test, well, anything really. These devices are the most unreliable meters we have. Has that s-meter been calibrated? If so by whom? Did they leave any notes? Did they test it just for 9 s-units or multiple different reading? If multiple readings how many? How long has it been? Can I examine it myself to verify it is still accurate?

I'm sorry, but every time I see someone referring to a s-meter reading I begin to doubt whatever it is they are saying. It is what it is.


The DB

 

[roadrage]

In reality an S meter may not tell anything with a degree of accuracy. Still, it can tell the difference between a stronger signal and a weaker one. My cheap Astatic power meter may tell me that my Galaxy 95t DK 90W and my Cobra 29 DK 10W. That is way off. In reality the Galaxy's DK is 30W and the Cobra's is 4W. But it can still tell me the Galaxy is putting out more power than the Cobra. To find out exactly how much more does need better equipment. My point is an S meter can still say that this signal is stronger than that one.

 

[W5LZ]

And just for grins...
That 4.15 dBi isotropic gain is the equivalent of about 2.0 dBd gain. Or the same as any 5/8 wave when compared to a standard 1/2 wave dipole. Actually, a 5/8 wave antenna's gain is slightly less than 2 dBd. But when talking about fractions of a dB, it's an almost meaningless difference (nit-picking over nothing).
- 'Doc

 

[The DB]

In reality an S meter may not tell anything with a degree of accuracy. Still, it can tell the difference between a stronger signal and a weaker one. My cheap Astatic power meter may tell me that my Galaxy 95t DK 90W and my Cobra 29 DK 10W. That is way off. In reality the Galaxy's DK is 30W and the Cobra's is 4W. But it can still tell me the Galaxy is putting out more power than the Cobra. To find out exactly how much more does need better equipment. My point is an S meter can still say that this signal is stronger than that one.

Assuming this is a hypothetical example, hypothetically speaking...

My first question would be, what did you do to that meter to screw it up that much? I suppose if it were an older meter it could have an internal component going bad, however, I have several meters that are over 20 years old at hand and all of them are much more accurate than that. As a matter of fact they all match up almost perfectly with my much newer Bird. To me that leaves someone messing with the meter in question... Several possibilities there not relevant to this discussion.

Even though it is so far off, the Astatic watt meter still gives you much more information than the receiving s-meter, and a much more accurate difference between the two in power. Yes it doesn't give you the exact amount of power each radio is transmitting, but it still gives you not only more, but more reliable info than an s-meter. All the s-meter is doing in your example is confirming what you already learned from the Astatic meter. If it is anywhere near accurate it will show about 1.3 or 1.4 s-unit difference between the two.

Your example has been nullified, as you gained no additional information from the use of the s-meter than you already had from the watt meter in question.

As I said, it is what it is.


The DB

 

[Needle Bender]

Yeah, I thought that might stir things up a little. It was getting boring out here.

So after all is said and done, (and there's usually a lot more said than done ) I can think inside the box and blame the antenna gain rating or the coax or the mast or the meter adjustment or the AGC or the isobars and the way the wind was blowing, but when I get 2-3 s units improvement, I'm happy! :w00t: And that's why I like the P500.

Shockwave you must be right because when I bought the Ringo it came from the estate of a local Ham operator and he had mounted it on an 8' fiberglass rod with the hub from an A99 radial kit drilled for 8 horizontal 24" long brass welding rods with a choke wrapped from mini8 coax and it was tuned best for channel 7. I left it as he had it and I think we used channel 12 back then if I remember right.

OK I'd like to hear from those who have had both a Sigma4 / Vector4K-type antenna, and a P500. How did their performance compare?

 

[Shockwave]

Yeah, I thought that might stir things up a little. It was getting boring out here.

So after all is said and done, (and there's usually a lot more said than done ) I can think inside the box and blame the antenna gain rating or the coax or the mast or the meter adjustment or the AGC or the isobars and the way the wind was blowing, but when I get 2-3 s units improvement, I'm happy! :w00t: And that's why I like the P500.

Shockwave you must be right because when I bought the Ringo it came from the estate of a local Ham operator and he had mounted it on an 8' fiberglass rod with the hub from an A99 radial kit drilled for 8 horizontal 24" long brass welding rods with a choke wrapped from mini8 coax and it was tuned best for channel 7. I left it as he had it and I think we used channel 12 back then if I remember right.

So the SP-500 does have 18 db over a half wave dipole? It must be because that's a lot of work to insure that 1/2 wave Ringo was working right.

OK I'd like to hear from those who have had both a Sigma4 / Vector4K-type antenna, and a P500. How did their performance compare?

I've done it several times personally over the years at more then one location since the 1980's. They are all good antennas and the difference is about a db or so. It all comes down to how the antenna handles the radiation currents past the half wave point. The point that will begin to introduce out of phase currents in the base.

The SP-500 does nothing to address that 1/8 wavelength on the radiator. The Sigma / Vector both handle that lower current lobe in an innovative way that has sparked debate for decades. NB, do you need a hub for your Vector so you can try this yourself? I'll send you one free if it will assist you in your own tests. Just email me where you want it sent.

 

[Needle Bender]

If you have one not needed, I would welcome it, and hope it leads to even better antenna performance.

May I PM you the info? Could I cover the cost of shipping?

And how do you think a bottom fed 1/2 wave compares to a center fed 1/2 wave dipole, if they are both installed with their tops at the same height?

My experience has me thinking that a lot of things are going on with the signal over distance, and not just relative to simple gain figures and varying atmospheric conditions, but even within static conditions, it seems one design beats others especially at distance as if there's more than meets the eye, such as possibly how the signal blends or cancels it's other angles depending on the E & F layers, and at certain distances.

The P500 always seemed to hang in there when other guys in my area were losing the signal on their APs, Stardusters, Sigma4s, Macos and Imaxs but I could still communicate on the P500. It kind of gave me a reputation for being one of the bigger stations in the area. Only the guys with the Sigma5/8 rivaled it.

Could you also send some measurements where I should begin tuning, or do you think the new Vector 3/4 specs are the way to go? And if you have a copy of their assembly manual I'd like to buy one of those, too.

 

[roadrage]

Assuming this is a hypothetical example, hypothetically speaking...

My first question would be, what did you do to that meter to screw it up that much? I suppose if it were an older meter it could have an internal component going bad, however, I have several meters that are over 20 years old at hand and all of them are much more accurate than that. As a matter of fact they all match up almost perfectly with my much newer Bird. To me that leaves someone messing with the meter in question... Several possibilities there not relevant to this discussion.

Even though it is so far off, the Astatic watt meter still gives you much more information than the receiving s-meter, and a much more accurate difference between the two in power. Yes it doesn't give you the exact amount of power each radio is transmitting, but it still gives you not only more, but more reliable info than an s-meter. All the s-meter is doing in your example is confirming what you already learned from the Astatic meter. If it is anywhere near accurate it will show about 1.3 or 1.4 s-unit difference between the two.

Your example has been nullified, as you gained no additional information from the use of the s-meter than you already had from the watt meter in question.

As I said, it is what it is.


The DB

The meter is the way it came from the factory. It is one of those real cheap meters. The needles also doesn't really move when the radios are modulating either. I only use it for the SWR window. My point was that even though it is totally useless, it still can say one radio is stronger than another. Just like an s meter can say it is seeing a stronger signal using one antenna vs another. But at the very least, when one antenna yeilded no signal and only static in the speaker, then the other antenna had an S meter reading and could clearly hear his buddy talking....that tells me more than the meter anyway. But the speaker may be out of calibration worse than the S meter.

 

[The DB]

The meter is the way it came from the factory. It is one of those real cheap meters. The needles also doesn't really move when the radios are modulating either. I only use it for the SWR window.

Ahh, so it's a broken meter. It still told you more than your s-meter.

My point was that even though it is totally useless, it still can say one radio is stronger than another. Just like an s meter can say it is seeing a stronger signal using one antenna vs another.

You still got not only more info but more accurate info from the broken watt meter. The s-meter told you pretty much the same thing only less specifically. Here is a question, what if your radios were transmitting say 20 and 25 watts. That might be a needles width difference on the receiving s-meter if that. Your broken watt meter would still show a difference and be much more clear about it. Do you think the person reading the s-meter would even realize the difference with the time in between spent unhooking one radio and hooking the other up? I would say no. It is thus limited to telling you you have a drastic difference in radio transmit power only. Again, your broken watt meter has already given you more detailed information than the receiving s-meter. Argument still nullified.

But at the very least, when one antenna yeilded no signal and only static in the speaker, then the other antenna had an S meter reading and could clearly hear his buddy talking....that tells me more than the meter anyway.

Which meter were you referring to with the "that tells me more than the meter anyway." I'm assuming you mean watt meter as if you meant the s-meter in that statement you would defeat your own argument.

Seriously though, the s-meter isn't telling you something you don't already know from just listening. What can you get from the s-meter that you can't get from just listening? What if his voice was in the static but clear? If it were the s-meter would actually provide less information than just listening. So again, argument nullified by using other, and this time free tools (your ears).

But the speaker may be out of calibration worse than the S meter.

Ha, very funny. You go ahead and believe its your speaker causing the problem...


The DB

 

[W5LZ]

In general, an 'S' meter is a relative reading device useful mostly for reference (your reference only). There are very few that are calibrated, and what calibration standard was used in that calibrating?
That reference thingy is for your use. When you try to make comparisons with someone else's 'S' meter readings you have mixed in who knows how many variables in that comparison. Got the same antennas, mountings of those antennas, things around those antennas, and that hasn't even touched on the accuracy of the two 'S' meters or propagation conditions. That's not all of the possible variation by any means, so putting a lot of importance on an 'S' meter reading just isn't very useful. Makes for a recordable number thought...
- 'Doc

 

[The DB]

In general, an 'S' meter is a relative reading device useful mostly for reference (your reference only). There are very few that are calibrated, and what calibration standard was used in that calibrating?
That reference thingy is for your use. When you try to make comparisons with someone else's 'S' meter readings you have mixed in who knows how many variables in that comparison. Got the same antennas, mountings of those antennas, things around those antennas, and that hasn't even touched on the accuracy of the two 'S' meters or propagation conditions. That's not all of the possible variation by any means, so putting a lot of importance on an 'S' meter reading just isn't very useful. Makes for a recordable number thought...
- 'Doc

He already acknowledged they are inaccurate...

In reality an S meter may not tell anything with a degree of accuracy...

I personally think hes just trying to get a rise out of me...

I was just putting forth that the two situations that he gave where as s-meter would be useful are pointless as other tools he has available already told him as much and more information. All the s-meter would do in the given situations is confirm what he already knew, and if you change the numbers much less that one might think, might not even do that.

So yes an s-meter is good only for personal reference, and not any more than that.

A more accurate meter that is not based on an exponential scale would be much more useful for any kind of actual measuring and comparing.


The DB

 

[AudioShockwav]

So yes an s-meter is good only for personal reference, and not any more than that.

Very True.

A lot of guys in the hobby simply do not understand how relative these meters are, there is no standard really and if you can not turn off the AGC on the radio off the reading`s are even more suspect.
It is just the way it is.
Very serious people that require very accurate results will test antennas using very expensive equipment....
The S-meter on a CB is not one of them so the results must be taken accordingly.
It is what it is.

 

[BOOTY MONSTER]

when i went from my home made wire star-duster to a home made maco 5/8 i had locals reporting up to 2 1/2 s-units more signal from me . did i believe i had up to 15 db more gain/signal from the 5/8 ? nope . all i really knew was that i was putting out a stronger signal . folks further out that couldn't or could barely hear me before without the little amp on had a copy on me barefoot and i could hear distant local stations that i couldn't hear before . so i didn't really know what the real difference was . but i had a very detectable difference and i was very happy with the result .

 

[roadrage]

He already acknowledged they are inaccurate...

I personally think hes just trying to get a rise out of me...

The DB

If I am offending you, I apologize. It isn't my intention. Just some friendly debate with a hint of sarcasm.

There was a quote that you responded to when the man said he had one antenna hooked up and couldn't hear his buddy and no response on is S meter. He changed antennas and could clearly hear his buddy and his S meter was reading 3. I'm not saying there was an 18db gain over the other antenna. How much gain was enough to take his buddy from not being heard, to being heard. That is enough gain make the difference between static and some rag chewing.
I am just saying that the S meter, though in-accurate, still said "hey this antenna is pulling in more signal than that one."

The speaker comment was in jest. You have to admit it was kind of funny.

 

[Marconi]

Very True.

A lot of guys in the hobby simply do not understand how relative these meters are, there is no standard really and if you can not turn of the AGC on the radio off the reading`s are even more suspect.
It is just the way it is.
Very serious people that require very accurate results will test antennas using very expensive equipment....
The S-meter on a CB is not one of them so the results must be taken accordingly.
It is what it is.

If this is true, then I believe it.

Why else then are all my signal reports so similar and showing hardly any difference among the antenna is have compared?

I also ask, how the do most that see nice clear differences in signals using their radios...get such different results from their radio meters?

If you guys are talking about SWR results, then "never mind."