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halfwatt959
08-31-2014, 10:29 AM
Howdy folks. I want to build my own base antenna just to do it. I don't expect any miracles, in fact failure on the first few tries. That said this is what I'm thinking: copper pipe in progressive sizes so they slide into each other for adjustment purposes with 4 ground radials of 3/8 copper pipe at 1/4 wave length set at 45-60 degrees. I'm currently undecided as to how to construct the gamma match. I also thought I would clear coat the whole thing to resist corrosion. Is the clear coat a bad idea? Is the whole project a bad idea? Was planning on 5/8 wave length since Ive benn informed that a full wave would have too steep of a radiation patern to be effective for practicle communication use. I am planning on using a choke at the feed point. Is this just dumb or is it semi-solid planning. There is nothing wrong with my Mako v5/8 I just want to make my own. Any help, advice and or tutoring will be greatly appreciated. Like I said I don't expect spectacular results or to reinvent the wheel just well just that I want to build my own junk. Thanks again 73s

Tallman
08-31-2014, 11:15 AM
The ARRL handbook has information for designing antennas. A vertical 5/8 wave made from copper would be expensive and hard to keep working due to corrosion. However if you went that way a light tin coat would help. There are ways to put tin coating on copper without hot dipping. Electro-less tin plating is one way.
Aluminum tubing would be best, but that's just my opinion.
The best antenna for skip shooting is a long wire horizontal. Once the signal bounces the polarity is ambiguous any way. Great for skip, not so good for local talking though. There is a lot less EMI on the Horizontal orientation.

halfwatt959
08-31-2014, 04:42 PM
Thanks for the input Tman. Aluminium would probably be better as you said but I cant get it from the local stores like lowes or home depot. That's the main reason for copper. It is readily available. However if I can find it online I will go with aluminuim . Just an experiment not spectacular results expected just want to say "I built it" Thanks again 73s Karl

Tallman
08-31-2014, 06:08 PM
http://www.speedymetals.com/c-8342-aluminum.aspx
The copper would be heavy and hard to mount up.
Certain ham vertical multiple band antennas are simply long wires supported by fiberglass or plastic tubing.

I made a CB ground plane from 1/2" conduit worked pretty good till a big storm knocked it down.

BOOTY MONSTER
09-02-2014, 06:32 AM
to use a gamma on a 5/8 you'll need to ad some length to the vertical without making it longer , aka coils , loops , tophat . the gamma will tune a 1/4 wave or a 3/4 wave vertical but not a 5/8 or a 1/2 wave . thats what wolf did on his .

http://www.wolfradio.com/p64.htm

1796

the gamma is for fine tuning on the wolf . you can also skip a matching network all together and add a large coil at the bottom and tap it for length like sirio did on one of their antennas . it's a open circuit antenna with no DC tap to ground .


https://www.youtube.com/watch?v=Jmh-RgkPPnw

when i made my 5/8 antennas i tried the tapped maco loop matching network and a tapped coil type ... i liked the maco loop type better . i had slightly better performance with the loop over the coil , but it could have been conditions because i didn't compare them on the same day . the loop was easier to make too . here they are .

http://i867.photobucket.com/albums/ab234/BOOTY-MONSTER/IMG_0065.jpg (http://s867.photobucket.com/user/BOOTY-MONSTER/media/IMG_0065.jpg.html)

http://i867.photobucket.com/albums/ab234/BOOTY-MONSTER/IMG_0037.jpg (http://s867.photobucket.com/user/BOOTY-MONSTER/media/IMG_0037.jpg.html)


http://i867.photobucket.com/albums/ab234/BOOTY-MONSTER/IMG_0019.jpg (http://s867.photobucket.com/user/BOOTY-MONSTER/media/IMG_0019.jpg.html)

BOOTY MONSTER
09-02-2014, 06:33 AM
had to break up my reply because i had too many pics .

heres the electrical image of the maco loop type matcher .

http://i867.photobucket.com/albums/ab234/BOOTY-MONSTER/antenna2.gif (http://s867.photobucket.com/user/BOOTY-MONSTER/media/antenna2.gif.html)

a cheap easy ground plane for testing or till you make something better is using four 108 inch copper wires on a PVC X below the antenna . i used two 10 ft sections cut in half with a PVC 4-way holding it together and ziptied to the mast .

http://i867.photobucket.com/albums/ab234/BOOTY-MONSTER/BELOWANTENNA.jpg (http://s867.photobucket.com/user/BOOTY-MONSTER/media/BELOWANTENNA.jpg.html)

copper is a slightly better electrical conductor than aluminum , but the difference is un-noticable on RF using human ears . special high tech equipment can detect a difference but human ears never will . and as already said copper is very heavy compared to aluminum . on a 22 1/2 ft. or longer vertical i'd be afraid it would snap due to it's own weight when raising it or with high wind loads . it will also oxidize very quickly and will not play as nice with aluminum or stainless steel (electrolytic corrosion) . aluminum to stainless/nickel aluminum is much much better .

you can use PEX refrigerator water line for a insulator in a gamma if you have to have a gamma match , but the tapped coil or loop is much easier than putting coils/toops/top hats on the vertical or finding the exact length on the sirio type open circuit with a coil on the bottom . and the loss difference between the tapped or open circuit antenna wont be a issue .

and don't be concerned about DC grounded (closed circuit antennas) myths .

http://www.iceradioproducts.com/80.html

when you want to step up to the best omni available ..... homebrew a beefy sirio vector 4000 antenna ... that's what i ended up doing ;)

Tallman
09-02-2014, 10:20 AM
copper is a slightly better electrical conductor than aluminum , but the difference is un-noticable on RF using human ears . special high tech equipment can detect a difference but human ears never will .
I agree totally with everything you said. I was misinformed about copper vs aluminum by a trusted source. Aluminum has less conductivity than copper. What I had been told was "The only reason copper wins over aluminum is the ease of connection using solder." I never questioned the "Trusted Source."
There bits and pieces of mobile antennas that could be adapted for tuning a base. http://www.hyelectronics.com/X-Terminator/products/41/

BOOTY MONSTER
09-02-2014, 02:14 PM
you can make your own coil too .


https://www.youtube.com/watch?v=XuOUITGSiaI&list=UUAReaqI5VTJ_255ExeWDf-w

BOOTY MONSTER
09-02-2014, 02:15 PM
BTW , here's my best homebrewed antenna .


https://www.youtube.com/watch?v=bHP1LzECHl4&list=UUAReaqI5VTJ_255ExeWDf-w

i ordered all my aluminum tubing from DX Engineering

http://www.dxengineering.com/search/department/rigid-tubing/part-type/aluminum-tubing/product-line/dx-engineering-aluminum-tubing?autoview=SKU&N=4294951163%2B4294951162&sortby=Default&sortorder=Ascending

made each order over the phone , everything went smoothly and arrived in 5 or less shipping days and was nicely packaged . i'll definitely order from them again if i need something they sell :)

ARCHBISHOP
09-05-2014, 07:55 AM
Hello booty great antenna design :300 (114): On another forum now ( closed ) a member built built bootys antenna an had great results.

NY714
09-09-2014, 02:56 AM
Howdy folks. I want to build my own base antenna just to do it. I don't expect any miracles, in fact failure on the first few tries. That said this is what I'm thinking: copper pipe in progressive sizes so they slide into each other for adjustment purposes with 4 ground radials of 3/8 copper pipe at 1/4 wave length set at 45-60 degrees. I'm currently undecided as to how to construct the gamma match. I also thought I would clear coat the whole thing to resist corrosion. Is the clear coat a bad idea? Is the whole project a bad idea? Was planning on 5/8 wave length since Ive benn informed that a full wave would have too steep of a radiation patern to be effective for practicle communication use. I am planning on using a choke at the feed point. Is this just dumb or is it semi-solid planning. There is nothing wrong with my Mako v5/8 I just want to make my own. Any help, advice and or tutoring will be greatly appreciated. Like I said I don't expect spectacular results or to reinvent the wheel just well just that I want to build my own junk. Thanks again 73s

I understand you want to build you own antenna, but unless you have plenty of extra time and access to a lot of high end aluminum parts, better off now-a days buys an antenna that was designed by a professional and made of high quality parts. They are cheap enough today, I do understand the need to make yourself, but unless your retired with plenty of time to design and access to a lot of high quality parts. It will probably work great for only a limited amount of time. Just my opinion with the low cost of antenna's and the high quality design of the antenna's on the market. Especially when spend thousands on the radio, what is a couple of hundred on an antenna.

mjd420nova
09-10-2014, 09:03 PM
I like to start off simple. Working with copper wire lengths to start with on wooden dowels, the trial and error become easier until you get the proper angles and SWR match. An Ant Spec M-400 starduster was great for a high takeoff angle making for better skip. A gamma match can be sorted out by looking at the length in relation to the main mast. Ground elements can be matched the same way, but a "good" ground is essential. Lengths of ground wire between the ground and the first point should be to the antenna first and another to the equipment, filters and dummy loads first then amps and xceiver.

BOOTY MONSTER
09-12-2014, 10:39 AM
hey archbishop , hope things are going well for you . i'm still plugging along spreading love and happiness wherever i can ;)

most new CB antennas sold today were not designed by professionals , they are just older designs copied with small differences in construction with the better ones having little to no difference in performance . the sirio gain master is different , but everything else is a copy of someone elses design from decades ago . some of them are sadly just confabulations with dumb ideas/parts/construction to impress the impressionable that don't know better with eye catching do-dads and/or big words used out of context to once again ...... impress the impressionable that don't know better . there are some very heavy duty 5/8WL antennas being sold for (IMO) way more than they're worth , but they're not electrically any stronger than original designs they're based on . `

parts to make antennas are not difficult to find or make or goober .... homerbb is proof of that . he has made some great performing antennas from scrap/junk laying around . he has made some fine performing antennas from PVC tubing wrapped in aluminum tape ! starting simple is great advise , simple designs (like a dipole) have less parts to make and assemble wrong so theres less chance of errors that can occur making someone feel they can't do it or that it's too complicated . the confidence gained from making a effective simple antenna will inspire you to make more complex and/or bigger designs with more potential performance . building antennas isn't for everyone , but it can be a very enjoyable part of the hobby .

BOOTY MONSTER
09-12-2014, 03:24 PM
...... A gamma match can be sorted out by looking at the length in relation to the main mast. Ground elements can be matched the same way .........

can you explain how the gamma design is effected my the mast ?
i had best results using 1/4 wavelength ground elements .

hotrod
09-21-2014, 12:08 PM
if i was to make any antenna id start off easy. the starduster type will be the easiest 3 radials and 1 verticle
element all 108 inches to start may need to trim off a couple inches . this design should be easy and best
of all no matching devise.to get best performance outta of this should try and get it 30 or higher above ground

Tallman
09-22-2014, 09:10 AM
Especially when spend thousands on the radio, what is a couple of hundred on an antenna.
There is a satisfaction of building an antenna that is a real "Ozone Burner" and you make reliable long distance contacts. Even if it is just a dipole stretched between two trees like a clothes line. But when you rack up contacts and there is a log jam of people trying to contact you during a contest or just a day of shooting skip is a nice problem to have and feels good that your home made antenna did it.

mjd420nova
09-22-2014, 10:03 AM
The length of the gamma match device needs to be in proper proportion to the vertical mast. Think of it like a transformer, the gamma match being the primary and the mast the secondary. The idea is to get the best induction of the RF into the mast while keeping the SWR to a minimum. Ground elements (counterpoise) can also be positioned to change radiation patterns as the also affect the SWR and can be tuned to broaden the bandwidth.