Homemade yagi

[mainetrunk]

Hi guys. As you may know by now, I'm REALLY into airwaves, and saving a buck to build my own antenna. Well, cut thru the bull and heres what I did..I got
1--. 16 inch hollow square aluminum tube
4-- aluminum rods 1/8 inch thick
And the connector ( 2 prong ) that goes to cable/R-S adapter to female bnc
And R-S jumper cable--bnc male to male
The 1st rod is 14 inches, 2nd is roughly 5 inch spacing to 8 inch rod, -5 inch spacing, to7 inch rod, ,,, next is the end 1 that is a 6 inch rod..
I got these parts from ripping apart a giant/big uhf/vhf tv antenna.. I'm even using those corled peices that hold the rod in place.... It does well in vhf mode AS IS, and until I get a permanent design, The bolts that hold the rods in place are 2 inches long,steel..
So, for now, I'm asking for proper instructions for a uhf, and a vhf.. I've seen other drawings, but noone specifies if this rod is supposed to be 5.6 INCHES, or centimeters..? I also got the long shaft off the old antenna cut in half.. 4 feet and slightly bigger than the above mentioned.. This IS 1 heck of a hobby!! Thanks a mil... 800's mhz and HF will be on the list later.
I got many rods, bigger than above if needed--- forgot-- ends of rods are tapered flat

 

[popnokick]

Couldn't tell exactly if there was a question in your post... but hopefully you know there is a "Build Your Own Antenna" Forum here on RR with lots of good info. In fact, you may want to look at this thread which has one of the replies with a link to a LPDA Calculator for element length/spacing in a Yagi:
http://forums.radioreference.com/build-your-own-antenna/300862-my-new-homemade-lpda-first.html

 

[mainetrunk]

I'm looking to build a vhf and a uhf yagi, needs specs, please, inches or other types of measurements...

 

[bailly2]

i used this website cse.unl.edu/~akoch/apps/Yagi_Waveguide.php built a good yagi out of coat hangers and a piece of wood for painting that blocks out interference great when the rods are vertical

 

[mainetrunk]

I hate to say it, that page doesn't fit on my screen

 

[W6KRU]

Here is the link: Yagi Antenna Calculator

 

[majoco]

Here's my cut down TV antenna. The long elements are the VHF air band cut for 125MHz = 24 inches each leg, the other two with reflectors are the old TV band 2 which is 200MHz thereabouts and the smaller one is 440MHz roughly.

 

[mainetrunk]

Now, THAT'S an antenna set up. I've been making holes, putting 2 inch bolts in. Adjusting spaces between. So far, I get some vhf, and a little t-uhf.. The rods I got are too big and the short one's have no signal at all. I went out today and got more bolt's and alot of wingnut's.. The above links don't fit my screen. So, I'm guessing ALL the way... I'll get there. Now to make some 2 foot rods. Thanks

 

[mainetrunk]

Perfect vhf yagi

Well, I did it, made a perfect yagi.. Heres how--- NO GENERIC CONNECTORS ALLOWED--LOL..
2 Meter Yagi Antenna w/ Gamma Match (Part 1/2) - YouTube

 

[mainetrunk]

Total guessing--5 element vhf

I just came up with a great vhf this time
24 inch 3/8 aluminum tube
22 inch "" ""
16 inch "" ""
14 inch "" ""
2- 6 inches "" ""
3/4 inch square tubing 22 inches long
24 incher goes 2 inches from end, dead center, tube goes thru square tube as tight as possible, 4 inches up, the 22 incher goes goes inches up from the 24... 4 inches later on square tubing, use the 2--- 6 inchers to go in and not touch each other. I use a rubber hose.( 1 inch long ) Place hose thru square tubing, drill 2 tiny holes thru tubing into top side of rubber. Do not go all the way thru.. Pull hose out, place the 2 -- 6 inches at both ends of hose. Leave a minor gap and re-drill the rubber hose to line up holes on tubing. Tiny holes. 2.. place rubber hose with tubing through the hole. You will have to enlarge it. Make sure it is a tight fit. Line up all holes on both sides. So, you can put a 1/2 inch long screws into square tubing, thru hose, into the 6 inch tubes. The 16 incher goes 4 inches down from last hole. Drill 3/8 hole, fit tubing in. 2 inches down, the last 3/8 hole for the 14 incher. Your coax will have to have outer cover removed, about 2 inches. Un ravel sheild, to be attatched to 1 of the 2 6 inch tubes.. Then peel back 1 inch to bare wire. They both get attatched to both screws at the 6 inch tubing. Put bnc on end, it works for me. The wire connection is the same as my post about uhf yagi's..
http://forums.radioreference.com/build-your-own-antenna/302099-3-element-uhf-yagi-home-brew.html
For 1 free rooftop uhf/vhf antenna, I made 2 uhf's and 2 vhf's... And I am no genious, just a guesser that got lucky.

 

[prcguy]

What is described does not make sense. So you have a boom that is 22" long and a 24" long reflector element then some other elements that are 22" then 16" then 14" and the two 6" pieces make up a 12" driven element of some kind?

If so that's not an antenna, its a bird perch or sock dryer or something other than an antenna.
prcguy

I just came up with a great vhf this time
24 inch 3/8 aluminum tube
22 inch "" ""
16 inch "" ""
14 inch "" ""
2- 6 inches "" ""
3/4 inch square tubing 22 inches long
24 incher goes 2 inches from end, dead center, tube goes thru square tube as tight as possible, 4 inches up, the 22 incher goes goes inches up from the 24... 4 inches later on square tubing, use the 2--- 6 inchers to go in and not touch each other. I use a rubber hose.( 1 inch long ) Place hose thru square tubing, drill 2 tiny holes thru tubing into top side of rubber. Do not go all the way thru.. Pull hose out, place the 2 -- 6 inches at both ends of hose. Leave a minor gap and re-drill the rubber hose to line up holes on tubing. Tiny holes. 2.. place rubber hose with tubing through the hole. You will have to enlarge it. Make sure it is a tight fit. Line up all holes on both sides. So, you can put a 1/2 inch long screws into square tubing, thru hose, into the 6 inch tubes. The 16 incher goes 4 inches down from last hole. Drill 3/8 hole, fit tubing in. 2 inches down, the last 3/8 hole for the 14 incher. Your coax will have to have outer cover removed, about 2 inches. Un ravel sheild, to be attatched to 1 of the 2 6 inch tubes.. Then peel back 1 inch to bare wire. They both get attatched to both screws at the 6 inch tubing. Put bnc on end, it works for me. The wire connection is the same as my post about uhf yagi's..
http://forums.radioreference.com/build-your-own-antenna/302099-3-element-uhf-yagi-home-brew.html
For 1 free rooftop uhf/vhf antenna, I made 2 uhf's and 2 vhf's... And I am no genious, just a guesser that got lucky.

 

[majoco]

IMHO he's getting mixed up between a Yagi and a log aperiodic.