M-104C to M-106C

[W5LZ]

One of those FWIW things

The average multielement beam on HF (any HF) isn't exactly what you'd call a 'spotlight' type of narrow beam width. It's more of a 'flood light'. Average 'beam width' is on the order of 60 degrees at the narrowest. They can certainly be made narrower than that but only at the expense of losing the FB advantage. Very narrow 'beam width' = no FB. If you can't keep the thing aimed at a mobile, and that mobile in on the earth's surface, and if that mobile isn't running micro-watts of power with in a very few miles of you, you got a problem with your antenna. A station more than just a few miles from you seeming to move 'left/right' of where your antenna is pointed just means that propagation isn't very steady, or your antenna has quite a 'wobble' to it (as in something's loose).
Transmitted and received radiation patterns are reciprical. Meaning that 'where' you hear is usually 'where' you are being heard too. There's always some variation to that, but not much. And what little variation there is is due more to other considerations, rather than 'beam width' or type of antenna being used.
- 'Doc

Oh, the difference between a 4 and 6 element beam antenna isn't day light/dark. More like clear skys and partly cloudy, if that makes any sense.

 

[DXman]

I put up the 6 element and really did not like it! It was not as broadbanded and I had to get it dead on the station because the front end was so closed. I put the 4 element back up. I did get about a .5 S unit more gain if I had it DEAD ON them by testing with other stations on flat but it wasnt worth the trade off for me. The best overall beam is a 4 element for me!

Turbo6, how long did you have the 6 up for testing?

It seems like I remember reading somewhere that the more broad-banded a beam is, the less efficent the antenna is. The tighter the beam width then the more the signal is concentrated in the direction that it's pointing.

FWIW
The beam width of my 5 is fairly tight (55 degrees-according to the model program I used) and I like it that way, it has excellent side rejection also. But if I could get the beam width down even tighter then I would do it.

Also...I prefer my beam to be Narrow band especially for my type of talking and that is - dxing to the other side of our planet.

 

[airplane1]

Would the maco 103HV be better than the PDL-2?

Both at 36-40 ft.

AP

 

[Master Chief]

Would the maco 103HV be better than the PDL-2? Both at 36-40 ft.

Be better how? Gain; YES. Weight; NO. Assembly; NO. Mechanically; NO.

I read back through this entire thread and want to make a couple of comments.

FIRST COMMENT
Any 11-meter beam at 85' is a mistake, DX speaking. It is too high. Let me explain. As the distance between a horizontal beam and the ground changes, so does the TAKE OFF ANGLE.

Think of a pool table and que ball. The angle the ball hits the bumper determines where the ball will end up. Too steep and the ball does not travel as far down the table. Decrease the angle and the ball will end up further down the table.

I don't know if you have a crank up tower or a fixed tower. If you have a crank up tower, start with the antenna all the way up. You can point the antenna towards Europe or the West Coast. Have a friend slowly lower the antenna while you are sitting in the radio room watching and listening to the radio. You will see different "skip zone" come and go as the antenna changes it's distance from the ground. You could talk to California at say 45' (just a random number for this discussion) and not hear him at all at 40'! At 36', Hawaii comes in. Try it and le us know what you learn.

For LOCAL (line of sight) communications, the higher the better! If you want to chase DX, you height above ground will change the skip zones you will talk into.

SECOND COMMENT
There are two ways to make gain. With an antenna or with an amplifier. The BEST money you will EVER spend on a radio system is on the ANTENNA and the FEEDLINE!

Buy a great stereo with so-so speakers and it will sound so-so. Buy a so-so stereo with great speakers and it will sound GREAT! Don't take my word for it, go check it out for yourself!

You will never go wrong buying or building a quality antenna!

THIRD COMMENT
Not all gain is good gain! Everything is a compromise! Longer booms generally have more gain, but at a cost (weight, $$$, support, mechanical integrity, beam width, etc). There was an article written years ago where a ham experimented with a popular Cushcraft 11-element 2-meter beam. He found that by removing 1 element and respacing them along the boom, that he had better gain and front-to-back!

Just because it has 6-elements does not make it better than a 5-element. Was it designed correctly? In the 20th edition of the ARRL Antenna Handbook, they take a popular Hy-Gain 4-element 20-meter monoband beam and change the spacing for better gain and front-to-back. Come to find out, the original design from Hy-Gain was more about the physical balance of the antenna rather than the electrical performance.

FOURTH COMMENT
The 5KW gamma! This gamma was designed to operate at higher power levels and will not be as efficient at lower power levels. If you are running up towrds 5KW all the time, then get the bigger gamma. A simple test will show that at modest power levels (100w), the original gamma will work better than the larger gamma. The 5KW gamma WILL work, but is not as efficient at lower power levels.

If you are serious about your hobby and like to build antennas, why not pitch the gamma and build a Beta-Match (hairpin)? Click the link and purchase the DXE BEB-2. You will also need a 8" - 10" section of 1/2" fiberglass rod to slide inside of the 5/8 tubing supplied by Maco. Cut the 5/8 section in half and and slide both ends over the fiberglass leaving an approximate 1" gap between the ends and mount them to the bracket. Then buy a DXE-HMS-1P Hairpin kit and build the driven element. It will take some experimenting but is a much better feed system (I wonder if that is why Jay is using it on the NEW Crusader beams or why most of the ham antennas use it?)

I'm sure I have more, but this post is long enough!

 

[FL Native]

MASTER CHIEF, thats he best antenna post ive ever read.

:beer :beer :beer

 

[excavator701]

question

then mastercheif what would be the best height for dx and local combined?? would you say 60 ?? 70?? feet useing a laser 400 cause i have 70ft of tower but i want best performance height is not an issue

 

[freecell]

it's not that good, the use of the term "skip zone" in the context presented is incorrect.

the "skip zone" is not talked into or heard from as it is the distance between the farthest points at which the ground wave can be received and the nearest points at which reflected skywave signals are able to be heard. the "skip zone" exists between these two points and can't be accessed unless the takeoff angles are raised, not lowered. no ground wave or skywave communications takes place in the "skip zone".

".......gamma was designed to operate at higher power levels and will not be as efficient at lower power levels." the gamma match does one thing and one thing only. it provides a match between feedpoint impedances that are less than 50 ohms to 50 ohm feedline. if it's rated to handle 2kw of power it does its job just as well at 2kw as it does at 2w. as long as impedance equals voltage divided by current the gamma match performs its primary function up to the limit imposed by the materials from which it is constructed, period. the ratio between voltage and current that establishes the match transformation values don't change just because the power applied is varied.

 

[W5LZ]

excavator701,
Not 'M.C.', but pick whatever height you want. There's no such thing as a ~'constant'~ best height, it changes all the time, just like propagation, and because of propagation.
- 'Doc

 

[airplane1]

I was told to get a antenna at least 36ft one wave length, the next best would be two wave lengths and so on till you hit I think a certain hight but I dont remember what that is. After you reach the max it wont help going ant higher.

Ap

 

[freecell]

while that may be true for certain vertical antennas over various types of ground it may not apply to the directional antennas under discussion here.

as you can see here for the feedpoint height of an end fed 1/2 wave vertical antenna over poor to very poor soil one wavelength above ground is the way to go if a low takeoff angle is what you're looking for with a minimal investment in support structure.

now back to the beams.

 

[W5LZ]

As displayed, that graph makes absolutely no sense.
- 'Doc

 

[freecell]

the horizontal axis represents feedpoint height above ground in fractions of a wavelength to one and the take off angle from five up to forty five degrees is represented by the vertical axis. four different soil types are plotted on the graph. pick a soil type and follow the colored line from left to right. average and poor soil start from the same marker and are overlapped as is evidenced by the blended geometry of the marker. select a bottom height above ground to determine the take off angle for any of the four soil types.

the soil types represented by the red and blue markers converge at .4 wavelengths and remain so until they separate at .8 wavelengths and go their separate ways.

 

[W5LZ]

Would have made a lot more sense if it was explained about the four soil types to start with. As it was displayed there was no explanation of what the 'very good', 'average', 'poor', and 'very poor' refered to, or that it was a graph representing the affects of soil conductivity to take-off angle.
- 'Doc

 

[freecell]

here was your first clue:

while that may be true for certain vertical antennas over VARIOUS TYPES OF GROUND........

here were your second and third clues:

the word ground appears in the heading at the top of the image (twice as a matter of fact) as in: "1/2 WL Vertical Above Ground"....ground = soil.

if you could read this was included in the same post below the image........here was your fourth clue:

"as you can see here for the feedpoint height of an end fed 1/2 wave vertical antenna over POOR to VERY POOR SOIL one wavelength above GROUND is the way to go if a low takeoff angle is what you're looking for with a minimal investment in support structure."

 

[Master Chief]

Re: question

then mastercheif what would be the best height for dx and local combined??

There is no "best height" for DX. The conditions are forever changing. What works today may not be the same tomorrow. For local, the higher the better.