new 55 merlin base antenna

[CDX-007]

I have seen this antenna test results and would like to pass along the info to everyone.
This has been copied with permision....

... needed with the I10k to cut down on bleeding since 5/8 wave antennas are notorious for signal comming down the coax.

... so i'm convinced

And another thing I noticed about this so-called comparison... The counterpoise system of 1/4 wave radials found on most 5/8 (.64) antennas decouples the coax from the possibility of feedline radiation, or common-mode currents.
I tend to use a common-mode current choke in the coax as a final preventative measure, but it is, for the most part, unnecessary when using an antenna with a counterpoise.

This was recently proven at John's (WR-897) home. He had always had problems with his own TV receiving TVI when using his newer-version Astroplane (Top Hat) antenna. We built a .64 from parts and pieces, including an old Hy-Gain CLR-II hub, made a 5-radial counterpoise and now he has no TVI, and WITHOUT a current choke in line. He doesn't even bother the neighbors TV & Stereo equipment anymore.

I find this entire comparison 'incredible' in the strictest definition of the term. The only application where I can accept that it might slightly excel over a .64 would be in Sporadic E - high angle short skip conditions.

 

[Robb]

OK - so you both think that the A99 is junk?!?
Don't think so...
You are comparing apples to oranges when comparing a A99 to a high-end expensive antenna. Let's remember that an A99 cost $65 and high-end antennas cost hundreds.
You get what you pay for.

Not to let it be said that the A99 is a bad antenna - it certainly is not. Many -if not most- people that I know of use them in the South Bay Area/San Jose CA - and make it thru the muck/miles and miles of urban sprawl quite well - too. My IMAX is a bit better and only cost slightly more. WIth a little power - taking skip isn't an issue - usually done often/well with 100-200 watts - no problemo.

Had I spent $375 for an antenna, I would expect perfection - and nothing less. A beam cost a lot to put up - when one considers the additional cost of a rotor and tower. Yikes!

 

[CDX-007]

OK - so you both think that the A99 is junk?!?
Don't think so...
You are comparing apples to oranges when comparing a A99 to a high-end expensive antenna. Let's remember that an A99 cost $65 and high-end antennas cost hundreds.
You get what you pay for.

Not to let it be said that the A99 is a bad antenna - it certainly is not. Many -if not most- people that I know of use them in the South Bay Area/San Jose CA - and make it thru the muck/miles and miles of urban sprawl quite well - too. My IMAX is a bit better and only cost slightly more. WIth a little power - taking skip isn't an issue - usually done often/well with 100-200 watts - no problemo.

Had I spent $375 for an antenna, I would expect perfection - and nothing less. A beam cost a lot to put up - when one considers the additional cost of a rotor and tower. Yikes!

I agree, your point of getting what you pay for is spot-on. But I hate it when manufacturers lie about gain to entice consumers to save money thinking they're going to also be getting performance.

Oh, just to rub salt in that wound, I bought my Penetrator for $55, (wish I would've bought 100 and put them away!!) - but that was back in '75.

I saw right at 2 S-units RX & TX improvement going from the A99 to the Imax2000 when I was in Reno in '02. They were mounted stealthy, from 6' above ground going up into a white birch tree.
Four different stations (just about everyone who HAS a CB in the Reno area!!) watched when I did the test and all 4 saw 2 S-units difference, as did I on RX.

To one of the guys, Stu, it was only 165 paces from my front door to his and he STILL saw 2 S-units improvement when I switched to the Imax and 2 S-units loss when I switched back to the A99.

I love it when lots and lots of stations use the A99 because I automatically have the advantage!

In fact, I believe the A99 is the best gift you can give a fellow CBer, ...if he lives real close to you.

 

[DoctorMaster]

If you understand antennas to at least some degree, you realize in a second that there isn't any benefit whatsoever with using a quarter wave antenna on 27mhz, and even if you have an HOA issue, and must use a quarter wave antenna, there is no benefit of adding a coil and/or top radials whatsoever. The reason, it's simply not needed in the design or for tuning a quarter wave antenna at all!! In fact, all you are doing is adding alot of extra components that just add loss, and if you have an HOA issue, you are just making the antenna "more" visable.. Think about it, if it was a straight stick, it would be much more stealthy and/or less of an eyesore, versus putting all these added components at the top to make it "stick out".. Adding coils or radials (or top hat) only adds loss, they do nothing to improve gain.. If you used a full sized quarter wave whip (or wire), with a RF ground, the SWR would be 1:1.The top hat and adding coils are worthwhile if you are trying to shorten the antenna significantly, but in this case, it would be far better (and cheaper) to use a 102" whip or wire, with none of this added at all. It would also be easier to conceal and hide.

 

[Splash1]

i always figer ,, base of antenna to base of antenna,,a good big un beats a good lil un every time..no matter how many bells ,whistles and purdy shinny things that are added to the lil,un..

 

[CDX-007]

i always figer ,, base of antenna to base of antenna,,a good big un beats a good lil un every time..no matter how many bells ,whistles and purdy shinny things that are added to the lil,un..

Well that's sometimes true. I've been building dual and triple 146mHz 5/8 wave collinear arrays for years and I've decided it's time to try building one for 11m.
I'm curious about how close it will come to performing as well as a neighbor's beam.

It will definitely be a "big 'un", 2 x 23' plus the center phasing coil, plus the bottom matching network.

I guesstimate about 48'-50' tall, but should also double as a 1/4 wave for 75m.

I'm hoping for +3dBP with an extremely low take-off angle which will hopefully add about 5-10dB at 80miles.
I'll hopefully see a big improvement in RX as well.

Should be fun, and I've already got the lighter top 23' made, just have to hit the local tubing outlet for some big stuff for the base.

...sure wish those 12kv lines were further than 40' away. Oh well, who knows, maybe they're only 4kv.

 

[W5LZ]

CDX-007,
...I'm almost afraid to ask, sort of hope it was just a missed key stroke, but...

What's that 'P' in the "+3dBP"?
- 'Doc

 

[CDX-007]

CDX-007,
...I'm almost afraid to ask, sort of hope it was just a missed key stroke, but...

What's that 'P' in the "+3dBP"?
- 'Doc

Ah, yes. Thank you for asking. I was wondering if anyone would catch that...
+3dB over a (Hy-gain) Penetrator.

 

[BOOTY MONSTER]

"I've been building dual and triple 146mHz 5/8 wave collinear arrays"

lol , ill admit up front i dont know what kind of antenna that is . got a question though . its my understanding that longer than a 5/8 or .64 and the signal starts going straighter up the taller you go . i know you know your feces about antennas so could you give a dummy down decricption of how it works and looks ? or provide a link to some not too technical info on it ?

thanks

 

[CDX-007]

"I've been building dual and triple 146mHz 5/8 wave collinear arrays"

lol , ill admit up front i dont know what kind of antenna that is . got a question though . its my understanding that longer than a 5/8 or .64 and the signal starts going straighter up the taller you go . i know you know your feces about antennas so could you give a dummy down decricption of how it works and looks ? or provide a link to some not too technical info on it ?

thanks

Sure, and I'm trying to get out o fhere for a BBQ but here's a link to a webpage with several simple designs you can peruse: 5/8 Collinear antenna by dxzone.com

And you're correct about the length of a SINGLE antenna, but a phased collinear is an antenna SYSTEM comprised of multiple 5/8 or 1/2 waves. Some even use several stacked 1/4 waves. I found the 5/8 easier and higher gain per foot, and the phasing coil is typically smaller and less lossy.

73

 

[DoctorMaster]

Big Hair Antennas have already became the first to make a collinear 11 meter base antenna a few year ago. It's about 48' tall total..

 

[CDX-007]

Big Hair Antennas have already became the first to make a collinear 11 meter base antenna a few year ago. It's about 48' tall total..

Oh really? Cool! I'm glad someone has put that excellent antenna design to use, though the design of a 5/8 collinear has been around for many decades.

48', yeah, that's about what I was thinking. I guess it takes a guy with big hair to build such a big antenna

 

[Mr Clean]

I get on both forums and really dont have a axe to grind for or against the 55 antenna but fussing about it one way or another without testing one is kind of useless. Let me go on to say I know nothing about the antenna in question. Someone over here needs to try one that has some clout as far as antennas go and get some ammo for or against this antenna to really know any more than we did after the first post. Just my 2 cents.

 

[DoctorMaster]

Mr. Clean, the antenna adds coils and a capacity hat to shorten a "quarter-wave" base antenna.. Why?? Adding components that aren't needed, only adds loss! This makes sense perhaps if running mobile where you need a smaller sized antenna, however it does nothing to improve gain. Actually, the best quarter wave antenna, is one without "no" coils or capacity hat whatsoever. These are being used to shorten the antenna (or to simulate a full sized quarter wave), thus only adds loss. For a base antenna, this doesn't make alot of sense, and again, you would be better using a 102" whip. Although the top placed coils/hat may be less lossy than other designs, the fact remains that the best solution is not adding any coil and/or capacity hat, or any other component that adds loss, compared to a full sized version.

A quarter wave doesn't need any of these components, as with an adequate ground plane and/or radials, the SWR can be 1:1 (or very close to) without adding any of that. Secondly, the concept they are used to hide the antenna in an HOA area, has no warrant, as it is only making the antenna stand out more, and more of an eye sore. You can by far hide a quarter wave, which is just a straight vertical thin whip.

It would be better for both scenarios, to just use a straight 102" vertical for the quarter wave base antenna.

 

[bob85]

doctormaster, ham international were selling the ham big-mac 5/8 over 1/4wave 11mtr colinear back in the early 80's,

55 is not the only one out there claiming the coil and hat lower radiation angle, signal engineering claim to be doing the same thing,

even avanti and hygain claimed a hat lowered angle of radiation,

is there a ratio of coil/hat and radiator length that gives a better signal on the horizon than a full length 1/4wave even if the maximum gain is lower than a full 1/4wave ?.