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new 55 merlin base antenna
- Thread starter bighammer
- Start date
maco.....v5/8.....slightly modded.....eighty bucks 'today'.....mine is up......cost far less then eighty bucks 'then'.....r=50....x=0.....1.1:1.....26.5-28.6 under 1.6:1.....ain't nothin' gonna be that much better to make it worth the effort to change.....
Exactly!
- Come-on, a 6' antenna outperforming a 23' 5/8?
There's nothing magic going on here, the coil on the 55 draws up the current from the feed point to the top, but how can one honestly imagine, even on a sunny day with a nice fresh cool breeze blowing through her hair as you enjoy all of life's wonderful.. oh, sorry I got a bit off track, that having the current at 6' above the mast is somehow better than having the current at 13'+ above the mast?
http://www.g4nsj.co.uk/images/58ths.jpg
And what about the capture area for RX? - 6' of antenna out-receiving 23'?
I know its early in the year and therefore a bit out-of-season, but the best remark I have to offer here is, "Bah, HUMBUG!".
It would sure be easy to test by building one out of a Starduster clone, but I wouldn't know if I had the right color code of flat bar aluminum so that it wouldn't end up being just a "Dummy load"...
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B
BOOTY MONSTER
Guest
i still think it looks like a m400/starduster with a funky top . i am interested in the way you can directly attach coax to it without using a pl259/so239 .
Which Maco 5/8, old or new?
Hey Dave, Is your 5/8 an early one (Wilson) and about 23' tall, or is it one of the newer Maco 5/8 that is about 19.8'-20'?
Hey Dave, Is your 5/8 an early one (Wilson) and about 23' tall, or is it one of the newer Maco 5/8 that is about 19.8'-20'?
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From the Instructions, Posted with the permission of 55:
The Merlin is a balanced antenna with direct feeding of the elements. RF Wave Shaping is acheived by redirecting RF that would normally leave the antenna in the direction of the sky and ground. All radiated power is in phase, thereby preventing distortion of the sine wave leaving the antenna. The feed point is 75 inches from the top of the antenna, allowing you to install the antenna in restricted areas with the feed point at the highest possible point. The gain of the Merlin in relative terms,is greater than any other antenna of the Merlin's same physical length. It is also greater than most conventional ground planes on the market today. The gain is not being expressed in db because other antenna manufacturers gain figures, expressed in db have made the figure deceptive. Power handling capability is limited by the SO239 connector, when used. For High Power operation, the antennahas been designed for easy removal of the SO239 bracket, and direct connect of large coax, with eyelets or brackets. RG218 or 1 5/8 hardline will fit on the hub easily.
The Merlin is a balanced antenna with direct feeding of the elements. RF Wave Shaping is acheived by redirecting RF that would normally leave the antenna in the direction of the sky and ground. All radiated power is in phase, thereby preventing distortion of the sine wave leaving the antenna. The feed point is 75 inches from the top of the antenna, allowing you to install the antenna in restricted areas with the feed point at the highest possible point. The gain of the Merlin in relative terms,is greater than any other antenna of the Merlin's same physical length. It is also greater than most conventional ground planes on the market today. The gain is not being expressed in db because other antenna manufacturers gain figures, expressed in db have made the figure deceptive. Power handling capability is limited by the SO239 connector, when used. For High Power operation, the antennahas been designed for easy removal of the SO239 bracket, and direct connect of large coax, with eyelets or brackets. RG218 or 1 5/8 hardline will fit on the hub easily.
i think you will find the answers as to why a 1/4 wave can outperform a 1/2 or 5/8wave endfed in this article,
the misinformation on how to install your base antenna often parroted on forums will have your endfed antenna warming the clouds,
i have tested what this guy says more than once and it works for me.
http://www.w8ji.com/verticals_and_baluns.htm
End-fed vertical j-pole and horizontal zepp I-max 2000 vertical
the misinformation on how to install your base antenna often parroted on forums will have your endfed antenna warming the clouds,
i have tested what this guy says more than once and it works for me.
http://www.w8ji.com/verticals_and_baluns.htm
End-fed vertical j-pole and horizontal zepp I-max 2000 vertical
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Whew! Good to hear all that coax-fed "Balanced" 1/4 wave current is "In phase"! Wouldn't want those 90 or so degrees of phase to be out of phase with, uhm, uh, well, ...itself, and - or well anything else anywhere else like all those other phases, or cars driving by with co-phased antennas, or Star Trek Phasers... uhm - yeah, ok, ...good... and all, you know, uh - yep, uh huh.
Oh boy.
Oh boy.
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B
BOOTY MONSTER
Guest
did you ever get your 55 antenna yet ?
if so , do you have any opinions on it yet ?
OK, I may have waxed a little sarcastic in my last post, but really now, a shortened 1/4 wave outperforming "Most conventional ground plane antennas..."?
Uhm, - if there are ground radials then it's more than likely a 5/8 wave since 1/2 waves do not require a counterpoise, (though it can sometimes help minimize RFI even on a 1/2 wave) so if you take the well-known information available regarding antenna theory & gain formulas you'll find a 1/2 wave has 2dB gain over a 1/4 wave with low angle radials (center fed dipole) and a 5/8 wave antenna provides 3dB gain over a dipole.
The best case scenario this 55 antenna could hope for is to perform as well as a center fed dipole, unless what is in question is a specific fix for a specific problem, that being: the transmitting station utilizing the 55 is in a serious HOLE!
Then does a 1/4 wave shine with regard to radiatiopn take-off angle being so high it can help to get signal out of the hole better than would a lower angle radiator like a 1/2 or 5/8 wave.
Now, having a coil near the top does nothing for raising of the current unless this were to be fed / matched with a coil or other form of phasing match at the bottom and phased as other than a 1/4 wave radiator, which it is not, as it has already been described to be a direct-fed 1/4 wave.
...and how is it the feed point is at 75inches high when the coax terminates at the base of the radiator, again, just like a Starduster...?
"Gain is not expressed in dB..." oh come on, are we now going to throw out a universal standard of performance measurement because one or two ding-a-lings make ridiculous claims? I think a sub-unity gain design isn't claiming to be because sub-unity gain isn't very flattering.
Sounds to me like hype upon hype, and frankly I'm offended at yet another antenna manufacturer making what are, in my opinion, ridiculous claims instead of just offering the truth about what it is and letting people who can use a shrunken 1/4 wave buy it for their specific needs.
It does, however, look to be a reasonably well-built, coil-shortened Starduster design, and should perform only a little under what a Starduster would.
Uhm, - if there are ground radials then it's more than likely a 5/8 wave since 1/2 waves do not require a counterpoise, (though it can sometimes help minimize RFI even on a 1/2 wave) so if you take the well-known information available regarding antenna theory & gain formulas you'll find a 1/2 wave has 2dB gain over a 1/4 wave with low angle radials (center fed dipole) and a 5/8 wave antenna provides 3dB gain over a dipole.
The best case scenario this 55 antenna could hope for is to perform as well as a center fed dipole, unless what is in question is a specific fix for a specific problem, that being: the transmitting station utilizing the 55 is in a serious HOLE!
Then does a 1/4 wave shine with regard to radiatiopn take-off angle being so high it can help to get signal out of the hole better than would a lower angle radiator like a 1/2 or 5/8 wave.
Now, having a coil near the top does nothing for raising of the current unless this were to be fed / matched with a coil or other form of phasing match at the bottom and phased as other than a 1/4 wave radiator, which it is not, as it has already been described to be a direct-fed 1/4 wave.
...and how is it the feed point is at 75inches high when the coax terminates at the base of the radiator, again, just like a Starduster...?
"Gain is not expressed in dB..." oh come on, are we now going to throw out a universal standard of performance measurement because one or two ding-a-lings make ridiculous claims? I think a sub-unity gain design isn't claiming to be because sub-unity gain isn't very flattering.
Sounds to me like hype upon hype, and frankly I'm offended at yet another antenna manufacturer making what are, in my opinion, ridiculous claims instead of just offering the truth about what it is and letting people who can use a shrunken 1/4 wave buy it for their specific needs.
It does, however, look to be a reasonably well-built, coil-shortened Starduster design, and should perform only a little under what a Starduster would.
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Kind of reminds me back when the Antron 99s first came out. Although I think they finally changed their advertising a while back, they began marketing the thing to CB'ers as having 9.9db gain, hence I guess the "99" in the name. All the while they also marketed the antenna to hams for use as a 10 meter vertical, but they knew they had to tell the truth to hams and claimed a 3db gain to them. Hype alert indeed.
Just depends on how you do that measuring of gain. A 1/4 wave antenna is 'sub-standatd' if that 1/2 wave antenna is used as the standard (which it very commonly is). With that same 1/2 wave standard, a 5/8 wave antenna has slightly more gain. But certainly not 3 dBd (or 'dBi' either, unless you start mixing those dB types, which you can't do), more like 1+ dBd. Standard measurements do work, and make comparisons much easier since you know what you are comparing the thing to. If you don't have a standard to go by, then those gain figures are absolutely meaningless. Is that gain as compared to a 32 element yagi, or a 'dead' beer can in the yard? Unfortunately, most of the gain figures typically seen in advertisements are related to that second comparison antenna.
- 'Doc
- 'Doc
Hey Doc, now I'm sure you know that a dBi rating is 2.15 higher than is a dBd rating, so how can you say a 5/8 (.64) antenna with at least 1.2dBd gain (depending on how the field strength tests are run) can't have a 3dBi rating?
Here's a respected website which supports your gain numbers for a 5/8: The Ultimate Guide to 11 Meter CB Antennas
But then there's Hustler, also a well respected antenna manufacturer: Mobile UHF & VHF
And what about the good ol' Hygain antenna company, do you trust them? They rated the Penetrator P500 Super CLR .64 at 5.1dB, and if that was a dBi rating then their dBd rating would've been 2.15 dB less, or right about 3dBd.
Here's the rub, all anyone has to do is erect a 1/4, 1/2, and a 5/8 (.64) antenna, then check the difference between them at, say, 30 miles. I've seen more like 10-15dB difference from the 1/4 to the .64 at that distance. That's why I have no use for near-field testing. It's how the antenna plays out at a distance that is the important spec, and having run the Penetrator against just about everything else out there, including an original Larry's LW-150 (easily the best built and heaviest omni antenna ever made, period, end of discussion!) I've seen it's at ever increasing ground wave distances where the .64 shows it's true colors and comes alive, heads and tails above other designs such as 1/2, .75, 7/8 etc...
And 3dBanything for the A99 must be in comparison to a wet mobile antenna, unless they simply forgot the minus sign before the 3.
Nope, I haven't invested the money yet.
You can direct fed almost any antenna. Just remove the connector and attach the coax directly to the proper elements.
I won't break apart the "Instructions" except to point out that the antenna is fed 75" from the TOP of the antenna. Its not 102" so they may be tapping the main radiator much like the Sigma IV. Although the Sigma IV uses a gamma. Not sure if this antenna uses a matching network. The use of the drooping radials should have raised the feedpoint closer to 50 ohms.
I'm still willing to put my money out there.....even if all this is, is a huge joke as he laughs all the way to the bank.
Anyone ever hear of an "RF Lens"? There are some strange antenna designs out there!