Home Brew 4:1 Air Core Balun...

[W4INF]

http://rogertango.com/images/hbaircorebalun.jpg

Coming soon, digital article on my site on step-by-step build of a home brew 4:1 air core BALUN.

Just got a check out of AL, +20 report, so it must be working. Also, with my HB doublet and Z-100, I am able to tune ALL bands 1.5 or less. With the Spiro 4:1 BALUN, I could not get below 2.5 on 80m and 20m.

You can see the first one I made, the "prototype" which also works 100% FB, however it was made with Romex and I used split bolts. The new one uses 14ga stranded and is all soldered. It should handle 1kw, at least 600w no problems. The Romex version should be able to do 1.5kw easily. Same plans, different materials. You can even step down to smaller wire for QRP!

In the next week, I will have a new post with the link to the article.


Thx 4 looking-
Andrew

[N8GAV]

I made one just like that one Andrew with #18 mag-enamel wire and incased it in a plastic Coke bottle. It worked better then I expected 1.2:1 or better 80-10 and 2.5:1 on 160 with my tuner. It handles 1 kw or so and was a lot of fun to built.

[W6GQ]

Is this your site?

http://rogertango.com/index.aspx



http://rogertango.com/images/hbaircorebalun.jpg

Coming soon, digital article on my site on step-by-step build of a home brew 4:1 air core BALUN.

Just got a check out of AL, +20 report, so it must be working. Also, with my HB doublet and Z-100, I am able to tune ALL bands 1.5 or less. With the Spiro 4:1 BALUN, I could not get below 2.5 on 80m and 20m.

You can see the first one I made, the "prototype" which also works 100% FB, however it was made with Romex and I used split bolts. The new one uses 14ga stranded and is all soldered. It should handle 1kw, at least 600w no problems. The Romex version should be able to do 1.5kw easily. Same plans, different materials. You can even step down to smaller wire for QRP!

In the next week, I will have a new post with the link to the article.


Thx 4 looking-
Andrew

[W4INF]

Is this your site?

http://rogertango.com/index.aspx


Yes sir, it is a continued work in progress... I still have a lot of coding to do to the web app to really finish it up. Written in VB/ASP.NET with a Access database back end and all done in Notepad. :p

Am I doing okay with it? Just curious...

PS
I just looked at the bottom of the page, I got my call and name on it. Doah!

Andrew

[w8unx]

Am I doing okay with it? Just curious...


Works fine in Firefox. Looking at your source, I'd suggest moving your CSS to an external file as it makes site-wide layout changes easier. There isn't anything wrong with in-lining your CSS, but if your site grows and changes, you will likely find it a pain to manage. Just my $0.02.

The balun is interesting. What are the specs on your homebrew doublet?

[W4INF]

Doublet is 90ft long fed with 75ft of RatShack 300ohm twinlead (foam core) at 25ft AG. BALUN is the 4:1 HB, and tuner is LDG Z-100, this setup is SMOKIN'!!

I have the 66ft doublet on my website, just sub 45ft legs for the plans and your working the same as me!

I have 2 of these, 1 is fixed and the other is in the back of the Jeep for portable ops. Now I need to build another BALUN for portable and put the LDG BALUN in the closet! HA HA!

What little bit of CSS I have, I am lucky TO have.... I know little about it, mostly an HTML guy and do a lot of ASP.NET programming. But thx for the tip, I will look into that!!! I know what your saying and I likely should do that.

Take care,
Andrew

[KC7YPJ]

got another project for ya andrew, take your 4:1 voltage balun wind a new one with 12-20 turns (20 is working for me), straight thru rather than the foldover wireing involved with the 4:1 voltage balun pictured, solder your so-239 on, center to white grnd to black (or whatever 2 colors you have chosen) other end of the windings slap couple of bananna jacks on and you've got an efective 1:1 current balun.

[W4INF]

Ryan, thx for the info! I was wondering what difference there was between a 4:1 and 1:1!

[EI8DRB]

Hi Andrew... nice site. Did you write the do the RSS puller yourself? Nice work if you did. The little tooltip popups are nice too... inobtrusive, but when you need them, there they are!
I'm more a LAMP developer than an ASP/.NET, but have great respect for anyone that can make Access do anything worthwhile :)

Looking forward to the balun plans.

[W4INF]

Hi Andrew... nice site. Did you write the do the RSS puller yourself? <snip>

Thx for the kind words... But what do you mean the RSS puller? I have not done anything with RSS at this stage.

Andrew

[W4INF]

I finished ahead of schedule!

http://rogertango.com/articleread.aspx?idnumber=34232411

HTH,
Andrew

[N2RJ]

I think I might actually build one.

Thanks.

[EI8DRB]

Thx for the kind words... But what do you mean the RSS puller? I have not done anything with RSS at this stage.

Andrew

Ah, I assumed that you were using RSS to pull the articles off QRZ

[n6yg]

http://rogertango.com/images/hbaircorebalun.jpg

Coming soon, digital article on my site on step-by-step build of a home brew 4:1 air core BALUN.

Just got a check out of AL, +20 report, so it must be working. Also, with my HB doublet and Z-100, I am able to tune ALL bands 1.5 or less. With the Spiro 4:1 BALUN, I could not get below 2.5 on 80m and 20m.

You can see the first one I made, the "prototype" which also works 100% FB, however it was made with Romex and I used split bolts. The new one uses 14ga stranded and is all soldered. It should handle 1kw, at least 600w no problems. The Romex version should be able to do 1.5kw easily. Same plans, different materials. You can even step down to smaller wire for QRP!

In the next week, I will have a new post with the link to the article.


Thx 4 looking-
Andrew

Hi Andrew;

Nice job, I have built something similar. Yours looks like a cleaner version of this design (http://www.bloomington.in.us/~wh2t/balun.html)

Unfortunately Twin lead baluns are far from optimal and have some serious issues.

You might be interested in reading Jim Browns K9YC Paper on Understanding Common Mode and Differential Mode Currents on Transmission Lines. (http://audiosystemsgroup.com/NCDXACoaxChokesPPT.pdf)
He goes into great detail about the drawbacks and issues with the common twinlead / bifilar balun.



Edit----------------------------
I just saw your web page with detailed step by step instructions. Great job I just forwarded it to my son. He's already in my shop scrounging parts.

These are a bit more complex, COAX BALUNS (http://www.xs4all.nl/~pa0fri/Ant/Balun/balun.htm)

73
N6YG

[kr2d]

Good build and nicely done tutorial, Andrew! I don't have need of a 4:1 voltage balun at the moment, but I have bookmarked your tutorial in case of future need.

[W4INF]

N6YG
That "ugly balun" page was one that gave me inspiration. And sure enough, its UGLY! HA HA! It really doesnt matter how it looks, as long as it does the job well!

Ill also be reading that transline page too, you got me interested! TU for the link OM!



N2JSO
TU Sir, I wanted to share what little knowledge I come across, the intent of my site, I hope in the spirit of Ham Radio. Kind words, which encourage me to do more.

I know many of my articles are simple... but so am I. :eek: We have to recognize there are operators of all different levels and abilities... I am still learning, and someone that was once in my foot steps will benefit from what I can pass on, or I hope so.



Andrew