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KC4UMO
01-11-2008, 05:28 PM
Hi all,
Yep it is me again.
Sorry.

I am wondering a few things on trapped yagi's.
Built plenty of mono band stuff and dipoles but like to know more about trapped antennas.

I have a lot of aluminum here. I also have a complete set of traps from an old TET HB33 tribander (with elements. Parts are lost so no way of reassembling this thing.

The HB33 according to the manual was actually a director and two driven elements. So the driven and director was insulated from the boom and the two halves of the elements was insulated from each other.

What I like to do is take what I have and build a triband beam. Join the element halves together and doing a direct mount to the boom.

I thought about just going ahead and doing this then feed the driven element with a gamma match. Then it hit me the the gamma would only tune one frequency. So most likely it will have to be fed with a balun or something. But either way it has to tune 10-15-20.

I not finding much information on this on the net.
Google is not helping.

Any information that someone can lead me to is most appreciated. Thinking that even 3db over the wire dipoles would sound more like 200 watts instead of 100 watts. With a beam antenna I should be able to reduce the qrm a bit.

Thanks for taking the time to read another one of my questions.

WA7KKP
01-11-2008, 08:58 PM
I'd think by the time you bought all the tubing, and traps that fit said tubing, you'd probably have the better part of the price of a new beam invested . . . unless you were a good enough scrounge at hamfests finding scrapped or disassembled tri-banders.

I'd think $100, maybe a bit more could get you a pretty good 3 element beam in fair condition, and you wouldn't have to futz with the design part. I admire your eagerness to tackle the project, but there are practical considerations in effect as well here.

I'd reccomend some of the smaller Beam Antenna Handbooks by Bill Orr, W6SAI as a good start. Also, single band beams are a snap to put together (no traps!).

Gary WA7KKP

KC4UMO
01-11-2008, 10:03 PM
Quote[/b] ]I'd think by the time you bought all the tubing, and traps that fit said tubing, you'd probably have the better part of the price of a new beam invested . . . unless you were a good enough scrounge at hamfests finding scrapped or disassembled tri-banders.
Hi Gary and thanks for replying .
As I said in the above post, I have lots of aluminum tubing. From 3 inch down to 1/4 inch. Lots in 8 foot sticks. I also have several sets of traps. Alot of this stuff came form just that. Buying old antennas that were took down and discarded. Even have some angle and square tubing here.

Quote[/b] ]
I'd think $100, maybe a bit more could get you a pretty good 3 element beam in fair condition, and you wouldn't have to futz with the design part. I admire your eagerness to tackle the project, but there are practical considerations in effect as well here.

Those I have not found yet. And believe me when I say I have been looking. I did find one local here but the going price was 300. He told me that the new was over 600. That want happen. Not that I am to tight http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif Just dont have it to spend. My thinking is build the antenna, buy some good coax to feed it. I did find a few tribanders on the net for sale, but with the price of shipping, yuk!

Those "practical considerations" are nice. But I like to learn though applying. If I build it, I have a better understanding of how it works. Yes I may fail, But I can start over and learn from the last time.


Quote[/b] ]
I'd reccomend some of the smaller Beam Antenna Handbooks by Bill Orr, W6SAI as a good start. Also, single band beams are a snap to put together (no traps!).

Gary WA7KKP
Yup, And I agree with you. And have done that. In fact, there is a 4 element 10 meter mono band and a 3 element 15 meter mono band antenna on the roof of the shack that I built some time ago. Nothing wrong with them. On the top of the tower there is a 16 foot homebrew 2 meter 70 cm quagi, below that is a 2 meter 12 element ssb homebrew and below that is a 6 meter homebrew.

I have experimented with one trap antenna and think I just got lucky with it. At the apex of the tower there is a 10-15-20 meter rotatable dipole. The element halves are insulated and feed with a W2AU balun. Then strait to the rig. I use it more than the wire dipoles. I find it has less noise and better receive over the wire dipole.

Thanks Gary for the reply. Your post has good suggestions for the average operator and should help many.
http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif

WA8RTI
01-11-2008, 10:11 PM
Agree with KKP. #A mono- band beam for 10, 15 or 20 wouldn't be hard but you are bitting off a big chunk to go for a tri bander. #Getting the traps tuned just right would be a real headache-not to mention the mechanical aspects of it. Orr books, if still in print, are great. Also ARRL the antenna book had a program with it that would design an antenna, give you the gain figures, element dimensions, F/B ratio, show the radiation pattern, side lobes, etc. The designs were however mono band.

W9GB
01-12-2008, 03:05 AM
Buddy -

Here is the rebuild of a 30-year old Cushcraft ATB-34 yagi antenna by DK4QT.
This antenna was the predecessor of the A-3 and A-4 antennas. #This is a work "in progress".
http://www.mydarc.de/dk4qt/basteln/atb34/atb34-beam.htm

You need your GDO or MFJ Antenna Analyzer to properly setup the coils. #DK4QT has supplied that data for your as well.


Quote[/b] ]I also have a complete set of traps from an old TET HB33 tribander.
You can also look at OH5YI's HB33M 3-element tri-band mini-beam (14, 21 and 28 MHz) -- seems like you situation. #
He added 50 MHz functionality - nice design appears to be his version of the Tet-Emtron TE33 (which is current version of your HB33)
http://www.kolumbus.fi/oh5iy/back/Ham%20Radio.html
http://www.tet-emtron.com/products/te33.htm

The Antenna Lab
http://www.hamuniverse.com/antennas.html

w9gb

KC4UMO
01-12-2008, 03:06 PM
Greg,
Now that is the stuff I was looking for. Thanks.
The TE-33 is very simular to the HB-33.
The manual on the HB-33 I have is so old and worn it is a pain to read. Not much info on the traps either. #The info you supplied gives me more detail on the way the tribander works.
Much appreciated.

KC4UMO
01-12-2008, 04:04 PM
Good news,

I just got an email from a guy here in town.
He just gave me a Hygain 3 element triband beam.
Going to pick it up next week.

Said it does require a lot of work but all parts are there.

Imagine that http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif

W9GB
01-12-2008, 09:09 PM
Quote[/b] ]The manual on the HB-33 I have is so old and worn it is a pain to read. Not much info on the traps either. #The info you supplied gives me more detail on the way the tribander works.

Send an e-mail query to Mark Rawlings at Tet-Emtron about your HB33 (they are about 12 hours ahead) on Sunday afternoon or early evening.

Mark might have an answer to you by Monday morning your local time. #

RAWMAR ENTERPRISES
40 Blackburn Street
STRATFORD
Victoria 3862
Australia
Ph: 61 3 5145 6179
Fax: 61 3 5145 6821
Email: info@tet-emtron.com

http://www.tet-emtron.com/

I am sure they can provide information on current parts as well as "update" to help you make that a fully functional TE33 antenna (which gets great reviews in Australia).

w9gb

KC9GUZ
01-13-2008, 03:57 PM
Good grief! 300.00 for a used tribander? I got a nice used Cushcraft A4 for 50.00 and it works great. I guess it pays to look around for a bargain!

KC4UMO
01-13-2008, 10:10 PM
Quote[/b] (KC9GUZ @ Jan. 12 2008,09:57)]Good grief! 300.00 for a used tribander? I got a nice used Cushcraft A4 for 50.00 and it works great. I guess it pays to look around for a bargain!
Thanks Greg I will give him an email.


Yup, 300 bucks!
Amateur equipment is high around here.

KA0GKT
01-13-2008, 10:38 PM
Quote[/b] (kc4umo @ Jan. 13 2008,15:10)]
Quote[/b] (KC9GUZ @ Jan. 12 2008,09:57)]Good grief! 300.00 for a used tribander? I got a nice used Cushcraft A4 for 50.00 and it works great. I guess it pays to look around for a bargain!
Thanks Greg I will give him an email.


Yup, 300 bucks!
Amateur equipment is high around here.
No Kidding!

You could have bought a brand new HyGain 3-element yagi (TH3MKIV) for only $169.95 more (at full retail price). If you don't plan to run full legal power, then you could have gotten by with a TH-3JRS for less than $60.00 more (again at full retail price).

Prices for Ham stuff must really be high in Greenville, SC.


73 DE KAGKT/7

--Steve

KC4UMO
01-13-2008, 11:49 PM
Quote[/b] (ka0gkt @ Jan. 12 2008,16:38)]You could have bought a brand new HyGain 3-element yagi (TH3MKIV) for only $169.95 more (at full retail price). #If you don't plan to run full legal power, then you could have gotten by with a TH-3JRS for less than $60.00 more (again at full retail price).

Prices for Ham stuff must really be high in Greenville, SC.


73 DE KAGKT/7

--Steve
Greenville NC..

People around here think highly of their stuff.
I wanted a third HF rig. I like to put one in the house. Everything Is out in the shack. My house is 80 foot long with a high pitch roof. Thought I lay a dipole on top. Be enough for whaen I am inside and dont want to go out to the shack and fire up the heater.

Someone told me about a ham here that lost his antenna during a storm in 1999. Said he still had his hf rig. I went over to look at it. Icom ic 745. With the built in power supply. $525.00. And would throw in a tuner for 50 more. I can drive 140 miles and get one for 325.

Yep, people are proud here.

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