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Building antennas

Thanks for the help

All,

I wanted to thank everyone for the information! I think my main issue here is that I am a over analyzer, I know how to put an antenna together - but it just can't be as easy as the books say (I have the ARRL Antenna book and am now reading it front to back, ugh - but thats another story). I have been a Ham for years and have stuck with pre made antennas because of all of the discussions you see on antennas, there seems to be so many types and opinions to each type that it just always seemed easier to go with a proven performer (gotta love eHam reviews). But as I become more educated and want to understand more about different parts of the hobby, buying commercial antennas just doesn't cut it.

So thank you all again for your comments, I will be continuing down the path of educating myself on antennas and antenna design and hopefully will be able to make some that will work for me.

Thanks again,

Michael
 
K8PG said:
The first thing you ned to do is get the ARRLs Antenna Book-study basic antenna theory,
then get The Basic Antennas Book-Their are many different antennas you can build
with wire ,you can have a lot of fun and learn a lot about antenna properties-Some wire
antennas can out-perform many commercial bought antennas,just depends what you make
Find a local ham that is well versed in building antennas-I am sure he will be glad to help
you.Good Luck-have fun and be Carefull.I at one time had 11 different wire antennas.
73/Dx.

Paul-K8PG
Click to expand...


Paul,

I am going out today to get The Basic Antenna Book - thanks for the info!
 
RickC. said:
Micheal,

First of all, congrats on becoming interested in building your own antennas-- the down side is, this stuff can eat your brain!

That said, the suggestion for the ARRL books are good ones, and don't be worried by any naysayers-- the posts were already deleted by the time I saw this thread, so I don't know what was said.

But you know, I am constantly surprised at the fear and trepidation expressed by some at building dipoles and such. It really is simple and they work well if attention is paid to mechanical and soldering details. Some people seem to be afraid they'll destroy their radios if they hook it up to something they built themselves or something that doesn't have a particular brand name. Nope...

The one suggestion I'd add is to find the highest wattage soldering iron (not gun) you can find because antenna wire makes an excellent heat sink and it can be hard to get up enough heat to make a proper joint with longer lengths of wire and the coax drawing heat away from the joint.

So, what's going to be your first project?


Rick
Click to expand...

Thanks for the info. My first project? Well - I had in mind that I would be looking at one of two things. 1) a wire antenna that would go around my house along / by / thru the rain gutter. I am in a area where I really can't have antennas showing. 2) An end fed 80 meter. I had a G5RV Jr up (having only a small black cable over the house isn't really noticeable), but the ladder line kept beating against my house - so I thought of doing a end fed and then just running the coax down the support tree next to my ham shack.

Thoughts?
 
kb7pzi said:
Ok, seriously, for some reason - the Lesson 1 of this doc explained antenna theory better than anything else I have read.

Thanks,

Michael
Click to expand...

Pretty straight forward as far as the explanation of theory.

The antenna design will depend on many factors. How you want to operate, DX or Local Rag chew or a little of both.

Size and height restraints, etc.etc.

Hams have been building some awkward antennas for years to get "around" HOA rules and regulations.

Build what you can with all constraints considered, and make some contacts.
 
I've done that "wire around the house" thingy and it seemed to work well, or well enough. Basically started as a random length wire and turned into a full wave loop on 80 meters. Originally fed it with a 1/4 wave of 75 ohm which worked, not well bu it worked. Then changed to ladder line and that made a world of difference in my particular circumstances. Naturally, used a tuner with that ladder line. No, the house wasn't that big (260 feet around, but there were trees at each corner. Used some thing like #14 wire for most of it, pieced together whatever else I had to make the full length.
I like loops! The bigger the better to some ridiculous extent. They can be used on higher bands and even provided some gain in particular directions. Some times that works out well, sometimes not.
Try different things, won't hurt a bit. Or much, anyway...
- 'Doc
 
wavrider said:
I am not sure but moving the driven element to the side away from being right on top of the reflector may make it just a simple dipole.

The spacing between the driven element and the reflector would have to be maintained, So the further to the side the driven element is the closer to the ground it would have to be to keep the .15 wl spacing between the driven element and the reflector,

Just my guess, for what it is worth.
Click to expand...


ok , so what if it was effectively the same as a super-scanner , laid on its side , but instead of using the S-S switch box use a separate run of coax to each top element and use a switch box ? thanks for endulging my curiosity :)
 
BOOTY MONSTER said:
ok , so what if it was effectively the same as a super-scanner , laid on its side , but instead of using the S-S switch box use a separate run of coax to each top element and use a switch box ? thanks for endulging my curiosity :)
Click to expand...

No problems on indulging the curiosity, it also makes me think outside the envelope or box per say, and that is a good thing.

As long as the reflector wire is laying on the ground as the diagram shows, the driven director will only be a little over 5 feet away from the reflector.

So straight vertical it is 5 feet above the ground, if it is moved to the left or to the right it is still 5 feet away from the reflector but the driven element is much closer to the ground.

This NVIS antenna is basically designed for daytime rag chews on the lower freq and it does work well for that, 7 mhz and below.

Reason is the length of the band.
27 mhz is roughly 36 feet for a wavelength .15 wl = 5 1/2 feet
7 mhz is around 140 feet for one wave length. .15 wl = 21 1/2 feet.

The NVIS antenna probably will not work to well on the higher HF freq. But it will work.
 
kb7pzi said:
Thanks for the info. My first project? Well - I had in mind that I would be looking at one of two things. 1) a wire antenna that would go around my house along / by / thru the rain gutter. I am in a area where I really can't have antennas showing. 2) An end fed 80 meter. I had a G5RV Jr up (having only a small black cable over the house isn't really noticeable), but the ladder line kept beating against my house - so I thought of doing a end fed and then just running the coax down the support tree next to my ham shack.

Thoughts?
Click to expand...

End fed half waves are fun to play with, and work well if you solve a couple of problems-- matching and grounding. I sure can understand getting around antenna restrictions, and one good thing about rolling your own is you can try different things without having to spend a bunch of money if something doesn't work well, or if your needs change.

How do you plan to match the end fed wire? Do you mean an end fed 1/4 wave or end fed 1/2 wave wire?

Rick
 
Antennas

Made and hung a 20 meter and a 40 meter dipole this weekend, embarrassed to say how easy the whole thing was. I didn't like using prefabricated feed point though - will be making my own for the next set.

Thanks for all the help everyone.

Michael
 
a mobile stud mount works well with home-brew antennas . it's still prefabricated though .
looking forward to what you come up with ;)
 
For my feedpoint, I used 1/2" PVC pipe.

I put a long notch through two opposite sides, then slid my twin-lead through that...I then split the twin lead outwards, and crimped/soldered on some lug connectors. I also crimped/soldered some lug connectors onto the dipole wire as well. I then predrilled two holes through both sides of the tube... I ran a 3/4" screw through the lugs one on top of each other, then through the holes.

My dipole has survived many storms.
 

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